Executive summary

What happened

On the afternoon of 16 September 2021, a Virgin Australia Airlines Boeing 737-8FE (B737) aircraft, registered VH-YIO, was conducting a scheduled passenger service from Sydney Airport, New South Wales (NSW), to Ballina Byron Gateway Airport (Ballina Airport), NSW. At the same time, a Cessna Caravan 208 (Caravan) aircraft, registered VH-YMV, taxied for a private instrument flight rules flight from Ballina Airport to Sunshine Coast Airport, Queensland.

While the B737 was on final approach to land on runway 24, the Caravan was taxied onto the runway and a take-off was commenced towards the approaching B737. The flight crew of the B737 conducted a missed approach to avoid the Caravan, during which they received a traffic collision avoidance system traffic advisory. At the closest point of approach, the lateral separation between the 2 aircraft decreased to approximately 0.9 NM with vertical separation reducing to about

700 feet. At the time of the incident, the aircraft were operating within the airport’s broadcast area and were both receiving a surveillance flight information service (SFIS).

What the ATSB found

The ATSB’s investigation identified that the Caravan pilot had an incorrect mental model of the traffic scenario, believing the B737 would land behind them on runway 06, rather than runway 24. The Caravan pilot had been provided with traffic information by the Ballina Airport SFIS controller, but the controller had not specified the landing direction of the B737 and the pilot had not sought this information.

The scenario was further compounded by the flight crew of the B737 not hearing the initial communications from the Caravan pilot, or the SFIS controller's response, and the flight crew remained unaware of the Caravan until just prior to it entering the runway. The Caravan pilot did not see the B737 approaching from the opposite direction and took-off directly towards it, resulting in the flight crew of the B737 to conducting a missed approach. No safety alert was issued by the SFIS controller as they were concerned that doing so would result in over transmitting communications from the aircraft in conflict.  

The ATSB also found that the SFIS had been implemented in an area with known surveillance coverage limitations, resulting in the SFIS controller having no displayed positional information for the Caravan until it reached an altitude of about 1,500 feet. Consequently, the controller was solely reliant on radio communications for situation awareness during the period of conflict between the Caravan and B737, significantly reducing their ability to provide appropriate traffic and avoidance advice.

What has been done as a result

Although reportedly an outcome of a post‑implementation review, rather than a response to this occurrence, Airservices Australia (Airservices) advised that there was an intention to install additional technology to improve surveillance coverage in the vicinity of Ballina Byron Gateway Airport by March 2023, but that timeline was dependent on a number of factors.

Noting the indefinite timeframe, in order to support Airservices’ intended action, including complying with a related recommendation issued by the Civil Aviation Safety Authority in its Ballina airspace review, the ATSB issued a safety recommendation to Airservices to address this surveillance limitation in a timely manner.

Safety message

Safety around non-controlled airports is an area of focus for the ATSB and a SafetyWatch priority. Pilots can reduce the likelihood of similar incidents occurring by communicating directly with aircraft on the common traffic advisory frequency when services such as a surveillance flight information service are provided. Additionally, pilots and controllers alike should ensure critical information is communicated and understood in order to maintain the accuracy of shared mental models.

The ATSB also strongly encourages the fitment of ADS‑B transmitting, receiving and display devices as they significantly assist the identification and avoidance of conflicting traffic. The continuous positional information that ADS‑B provides can highlight a developing situation many minutes before it becomes hazardous – a significant improvement on both point‑in‑time radio traffic advice and ‘see‑and‑avoid’. The ATSB also notes that ADS‑B receivers, suitable for use on aircraft operating under both the instrument or visual flight rules, are currently available within Australia at low cost and can be used in aircraft without any additional regulatory approval or expense.

The occurrence

On the afternoon of 16 September 2021, a Virgin Australia Airlines Boeing 737-8FE (B737) aircraft, registered VH‑YIO (Figure 1), was conducting a scheduled passenger service from Sydney Airport, New South Wales (NSW), to Ballina Byron Gateway Airport (Ballina Airport), NSW. There were 2 flight crew, 4 cabin crew and 47 passengers on board. The captain was pilot flying (PF) and the first officer (FO) was pilot monitoring (PM).[1]

Figure 1: VH-YIO

Source: Supplied

At 1332:33 Eastern Standard Time,[2] when the B737 was approximately 44 NM to the south of Ballina Airport, the FO made an initial positional broadcast on the Ballina Airport common traffic advisory frequency (CTAF) [3] (see the sections titled Broadcast area and Common traffic advisory frequency). This broadcast was acknowledged by the Ballina surveillance flight information service (SFIS) controller (see the section titled Surveillance flight information service).

At 1335:15, the B737 FO made another broadcast on the Ballina CTAF advising that the aircraft was now 27 NM south of Ballina Airport and would land on runway 24 at an estimated time of 1345.

Meanwhile, the pilot of a Cessna Caravan 208 (Caravan) aircraft, registered VH-YMV prepared for a private instrument flight rules (IFR) flight from Ballina Airport to Sunshine Coast Airport, Queensland. The pilot was the only person on board and the purpose of the flight was to reposition the Caravan to the Sunshine Coast for parachute operations.

The Caravan pilot had flown a different aircraft from Sunshine Coast Airport to Ballina Airport earlier that day. On arrival at Ballina Airport, the pilot undertook a prefight inspection of VH-YMV and readied the aircraft for the flight.     

At 1338:00, the B737 FO made a further broadcast on the Ballina CTAF advising that the aircraft was now 15 NM south‑east of Ballina Airport and would be positioned for a 10 NM final to land on runway 24 at a time of 1345.

At 1341:17, the Caravan pilot made a taxi broadcast on the Ballina CTAF advising that the aircraft would depart from runway 06 for an IFR flight to the Sunshine Coast. At the time, the weather recorded by the aerodrome weather information service (AWIS) indicated a few clouds at 2,600 feet above ground level, visibility greater than 10 km and a 12-17 knot wind from a 160-170° direction. The pilot recalled listening to AWIS and noting a crosswind. Although this wind direction favoured a departure from runway 24, the pilot recalled observing the windsock, assessing it favoured a departure from runway 06, and hence electing to do so. The aircraft was parked on the general aviation apron and the pilot chose to take-off from the intersection of taxiway A and runway 06, which involved a short taxi to the hold point with no backtracking along the runway.

At 1341:27, the SFIS controller responded to the Caravan pilot’s broadcast and provided the pilot with traffic information on the B737 and a Jetstar Airbus A320 (A320), registered VH-VQK, that was also inbound to Ballina Airport (Figure 2). The SFIS controller stated:

Yankee Mike Victor squawk 4547. Traffic [is] Velocity 1141, 737, shortly turning onto a 10 NM final, followed by Jetstar 464 an Airbus 320 currently 20 NM to the south-west and they're tracking for a right downwind runway 24. They'll be crossing centreline at about time four five.

Figure 2: At 1341:51, the pilot of the Caravan advised the SFIS controller that they had copied the traffic and correctly read back the transponder squawk code. Figure 2: A320 and B737 locations at 1341:27

Source: Google Earth, annotated by the ATSB

The flight crew of the B737 did not recall hearing the Caravan pilot’s taxi broadcasts or the SFIS controller’s responses to the taxi broadcast on the CTAF and were unaware of the presence of the Caravan. The SFIS controller noted that the B737 flight crew had not responded to the Caravan pilot’s taxi broadcast but did not confirm if they were aware of the Caravan (see the section titled SFIS procedures).

The B737 continued the approach for Ballina Airport and, at 1341:57, made a left turn onto a 10 NM final for runway 24.

Meanwhile, the Caravan pilot had formed the belief that the B737 would land on runway 06 based on their earlier observation of the runway windsock. The pilot had also misunderstood the traffic information provided by the SFIS controller as meaning that the B737 was on approach for runway 06, not runway 24, and hence believed that the Caravan could depart ahead of the arriving B737 without causing a conflict. The pilot recalled conducting a visual check for traffic before entering the runway but did not see the B737 that was on final approach to land on runway 24 (see the section titled Human factors).

At 1343:28, the pilot of the Caravan made a broadcast on the CTAF stating that the aircraft was entering and rolling runway 06 (Figure 3).

Figure 3: Caravan and B737 locations at 1343:28

Source: Google Earth, annotated by the ATSB

The SFIS controller heard the Caravan pilot’s ‘entering and rolling’ broadcast and was aware of the developing conflict between the Caravan and the B737. However, the SFIS controller elected not to issue a safety alert (see section titled Safety alert).

The ‘entering and rolling’ broadcast was the first transmission the flight crew of the B737 recalled hearing from the Caravan pilot and when they first became aware of the Caravan. At 1343:36, the B737’s FO made a broadcast on the CTAF stating that the B737 was on a 5 NM final approach for runway 24. Neither the Caravan pilot nor the SFIS controller responded to this broadcast.

At about 1344:00, the Caravan pilot commenced the take-off directly towards the approaching B737.

At 1344:15, the B737’s FO made a further broadcast on the CTAF querying the Caravan’s location. At 1344:19, the Caravan’s pilot responded stating that the aircraft had just become airborne from runway 06 (Figure 4). The B737’s FO immediately replied asking if the Caravan pilot could see the B737, which was now on a 3 NM final for runway 24. At 1344:36, the Caravan pilot confirmed sighting the B737, and its FO then requested the Caravan pilot to commence a turn. The Caravan pilot did not respond to the FO’s broadcast, but the pilot did initiate a turn to the right shortly after becoming airborne.

Figure 4: Caravan and B737 locations at 1344:19

Source: Google Earth, annotated by the ATSB

At 1345:06, the captain of the B737 initiated a missed approach and, a short time later, the flight crew sighted the Caravan ahead of their aircraft, travelling in a northerly direction. During the missed approach, the flight crew received a traffic collision avoidance system[4] traffic advisory[5] generated by the Caravan’s proximity. The flight crew maintained visual contact with the Caravan and repositioned the B737 for a left circuit to land on runway 24.

A review of recorded flight data indicated that the closest point of approach occurred at 1346:12 as the lateral separation between the 2 aircraft decreased to approximately 0.9 NM with vertical separation reducing to about 700 feet (Figure 5).

Figure 5: Caravan and B737 tracks and relative distances

Source: Google Earth, annotated by the ATSB

The Caravan pilot set course north for Sunshine Coast Airport and communications with the aircraft were transferred to the Brisbane Airport approach controller at 1349:26. The B737 landed at Ballina Airport at about 1359:00.

Context

Personnel information

B737 flight crew

The captain held an air transport pilot licence (ATPL) (aeroplane) and had a total flying time of 15,719 hours, having flown 25 hours in the previous 90 days. The captain was familiar with Ballina Airport and had operated there in both turboprop and jet aircraft over a 20-year period.

The FO held an ATPL (aeroplane) and a total flying time of 8,607 hours, having flown 72.3 hours in the previous 90 days. The FO was also familiar with Ballina Airport having operated there in both turboprop and jet aircraft throughout their career. The FO’s last flight to Ballina Airport took place on 11 May 2021.

Caravan pilot

The pilot held a commercial pilot licence (aeroplane) and a total flying time of 1,008 hours, having flown 50 hours in the previous 90 days. The pilot was familiar with Ballina Airport and had last flown into the airport approximately 3 months prior to the incident flight.

Controller

The surveillance flight information service (SFIS) controller had experience in both tower and en route air traffic environments prior to commencing in the SFIS controller role. The controller was based in the Airservices Australia Brisbane Centre and had undertaken SFIS endorsement training in August 2021, before the SFIS service commenced on 12 August.  

Ballina Byron Gateway Airport

Ballina Byron Gateway Airport is situated approximately 3 NM from the city of Ballina, NSW. The airport has an elevation of 7 feet above mean sea level (AMSL) and a single sealed runway, orientated in a 062°-242° magnetic direction (Figure 6). The airport had global positioning system (GPS)‑based instrument approaches and a non-directional beacon ground-based navigation aid.

Figure 6: Ballina Byron Gateway Airport

Source: Airservices Australia

Airspace and traffic services

Ballina Airport was located within non‑controlled Class G airspace, which extended from the ground surface to 8,500 feet AMSL. The airport did not have a control tower and was not supported by an air traffic control separation or sequencing service (that is, a non-controlled airport).

Overlying the non‑controlled airspace was Class C controlled airspace which extended up to flight level (FL) 180,[6] and controlled Class A airspace above that. An air traffic information and separation service was provided within the Class C airspace and a separation service was provided within the Class A airspace. A restricted area existed approximately 5 NM south of the airport (the aircraft involved in this incident were clear of this area).[7]

The non‑controlled airspace surrounding Ballina Airport was available for use by aircraft operating under visual flight rules and instrument flight rules. The primary method of traffic separation at Ballina Airport was visual and relied on pilots using ‘alerted see-and-avoid’[8] practices.

A broadcast area (BA) was in place within an approximate radius of 15 NM from the airport and a surveillance flight information service (SFIS) was provided to aircraft operating within the BA during defined periods (see the section titled Surveillance flight information service).

Broadcast area

Surrounding Ballina Airport was a BA that mandated the carriage and use of radio equipment for aircraft operating within a radius of 15 NM of the airport, from surface level to 8,500 feet, excluding penetrating arcs of circles for Lismore Airport and Gold Coast control area steps (Figure 7).

Figure 7: Ballina Airport broadcast area

Source: Google Earth, annotated by the ATSB

The broadcast area was expanded from 10 NM to 15 NM on 28 January 2021 to ‘reduce residual airspace risk’. The expansion of the BA occurred following a separation incident involving a Jetstar A320 and a Jabiru aircraft that occurred about 13 NM from Ballina Airport on 28 November 2020 (see ATSB investigation AO-2020-062).

The broadcast area required all pilots to make mandatory positional broadcasts when entering or operating within the defined lateral and vertical limits of the BA on the Ballina Airport CTAF. Pilots were also required to acknowledge calls from aircraft departing or landing whose operations were in conflict with their own, and should announce when in receipt of a call indicating that their aircraft may be in conflict when operating outside of the circuit area.

Common traffic advisory frequency

The Ballina Airport CTAF was a designated radio frequency on which pilots made positional broadcasts when operating in the vicinity of the airport. The Ballina Airport CTAF was shared with neighbouring airports and aeroplane landing areas at Casino, Lismore and Evans Head.

A surveillance flight information service, detailed in the following section, was provided on the CTAF to aircraft operating within the Ballina Airport BA.

Surveillance flight information service

A surveillance flight information service (SFIS) was provided to aircraft operating within the Ballina Airport BA between 2200-0800 Coordinated Universal Time [9] (1 hour earlier during Eastern Daylight-saving Time[10]) or as notified by notice to airmen.

The SFIS utilised available surveillance data, and broadcasts on the airport’s CTAF, to provide all visual flight rules (VFR) and instrument flight rules (IFR) aircraft with a full traffic information and alerting service. The information provided by the SFIS controller contained advice on conflicting traffic. However, the SFIS was not a separation or sequencing service and pilots remained responsible for seeing and avoiding other aircraft.

The service was provided by a dedicated Airservices Australia air traffic controller located at the Brisbane Centre. Pilots made broadcasts and reported to the SFIS controller (callsign ‘Ballina Information’) on the Ballina Airport CTAF.

The SFIS commenced on 12 August 2021 and replaced the previously established certified air/ground radio service (CA/GRS). The CA/GRS was provided at Ballina Airport from March 2017 to the commencement of the SFIS service in August 2021 and was delivered by a certified air/ground radio operator (CA/GRO) located at the airport.

SFIS procedures

Airservices Australia procedures required the SFIS controller to communicate specific details when passing traffic information to aircraft. This information was to include the traffic’s intentions, the traffic’s reported position and estimate. The SFIS controller was also procedurally required to provide traffic information to aircraft in class G airspace when an aircraft was expected to arrive with less than 10 minutes separation time from aircraft departing from the same airport.

During this occurrence, the SFIS controller provided traffic information to the Caravan pilot that did not include the B737’s estimated landing time and runway number. The controller stated that as the pilot’s communications appeared to be ‘competent’ and ‘confident’, it had not been considered necessary to emphasise the B737’s landing direction. Similarly, when the B737’s flight crew did not respond to the Caravan pilot’s taxi broadcast, the controller did not consider it necessary to confirm they were aware of the Caravan because, according to their SFIS training, they were not required to follow-up communications for aircraft already on the CTAF (as was the case for the B737).

Safety alert

A safety alert comprises advice provided to a pilot when the SFIS controller becomes aware that an aircraft is in a position that places it in unsafe proximity to terrain, obstructions, active restricted or prohibited areas, or another aircraft. In cases where an aircraft is in close proximity to another, a safety alert should be issued by the controller unless the pilot had advised that action to resolve the situation was being taken, or the other aircraft was in sight. A safety alert could be issued in all classes of airspace both within and outside surveillance coverage.

However, on the day of the occurrence, the SFIS controller did not issue a safety alert to either the B737 or the Caravan after its pilot reported entering and rolling runway 06 although it was apparent to the controller that a conflict would result. The controller advised that their reason for not doing so was due to a concern that the alert could result in the over transmission of radio communications from either aircraft.

Technical systems

Secondary surveillance radar

Secondary surveillance radar utilises ground stations (interrogators) and transponders on board aircraft.

A transponder is a receiver/transmitter which transmits an automatic reply upon receiving an interrogation request. A manual ‘ident’ transmission can also be initiated by the pilot. The information that may be transmitted by a transponder is dependent on the ‘mode’ of equipment fitted to an aircraft:

• Mode A transponders transmit an identifying code only
• Mode C transponders transmit an identifying code and altitude (based on standard pressure)
• Mode S transponders transmit an identifying code, altitude (based on standard pressure) and permit data exchange

The signal from the transponder is received by the ground station and combined with the aircraft’s position established via radar (range and bearing). This information is then relayed to air traffic control where it is displayed on the controller’s console screen.

Automatic dependant surveillance broadcast

Automatic dependent surveillance broadcast (ADS-B) utilises electronic equipment on board an aircraft to automatically broadcast the aircraft’s precise location, and other parameters, via digital data link (ADS-B OUT). The data is then used by air traffic control and other aircraft to depict the aircraft’s position, and other information, on a display without the need for radar.

The system uses GPS data to determine the aircraft’s position then transmits the position, and other parameters (such as identity, altitude and speed), at rapid intervals. These transmissions are received by dedicated ADS-B ground stations and the information is then relayed to air traffic control and displayed on the controller’s console screen.

The transmissions can also be received by other aircraft with the capability to receive and displayed this information (ADS-B IN). Both the B737 and Caravan were fitted with ADS-B OUT equipment. Neither aircraft was fitted with ADS-B IN equipment, nor were they required to be.

Surveillance coverage

The SFIS was a surveillance-based service that utilised secondary surveillance radar (SSR) and ADS-B information, in combination with pilot broadcasts made on the CTAF, to provide pilots with traffic information and alerts.

Documents developed by Airservices Australia before implementing the Ballina Airport SFIS contained a list of ‘critical components’ necessary for the service. Although ‘adequate surveillance coverage’ was one of these critical components, Ballina Airport had no ADS-B ground station and the surrounding area had significant limitations in SSR and ADS-B coverage. Surveillance coverage charts produced by Airservices Australia indicated that, near the airport, the SSR and ADS-B coverage did not commence until about 1,500 feet above ground level (Figure 8).

Figure 8: SSR and ADS-B coverage within the vicinity of Ballina Airport

Source: Airservices Australia, annotated by the ATSB

The hazards and risks associated with the surveillance coverage limitations were identified by Airservices Australia prior to the implementation of the SFIS and documented as:

Limited surveillance coverage may lead to unintended aircraft proximity (Airprox), inadequate separation assurance (ISA), or loss of separation (LOS) occurrence.

Airservices Australia conducted a risk assessment and rated the initial risk as moderate. However, its pre-implementation risk treatment did not reduce the risk any further. Residual risks associated with the surveillance coverage limitations were formally accepted and the SFIS was implemented with the risks unaddressed. These limitations meant the Caravan’s positional information was not displayed on the SFIS controller’s console screen until it reached an altitude of about 1,500 feet, which occurred about 100 seconds after take-off was commenced.

Previous events

A search of the ATSB occurrence database found that during the period from the implementation of the SFIS (12 August 2021) to the date of the incident (16 September 2021), there was one reported occurrence and no reported separation issues within 20 NM of Ballina Airport.

Regulatory oversight

The Airspace Act 2007 assigned the administration and regulation of Australian administered airspace to the Civil Aviation Safety Authority (CASA). As part of this function, CASA was required to undertake regular reviews of airspace to determine if existing classifications were appropriate, air navigation services and facilities were suitable, there was safe, efficient, and equitable use of airspace, and identify any associated risk factors.

On 15 December 2022, CASA publicly released a final Ballina airspace review. The review identified 3 areas of concern:

• Frequency congestion
• Heightened risk of separation incidents
• Situational awareness

As a result, the review made 9 recommendations (Table 1).

Table 1: Ballina airspace review recommendations

Source: Airspace Review of Ballina – 2022 with minor amendments by the ATSB

On 16 June 2022, recommendation 1 and 2 were implemented resulting in Lismore, Casino and Evans Head being separated from the Ballina Airport CTAF. Recommendation 3 was due for implementation by April 2023 and proposed the installation of an ADS-B ground station in the vicinity of Ballina Airport to provide surveillance coverage to the runway surface.

The ATSB undertook a detailed assessment of CASA’s role in the oversight of the airspace surrounding Ballina Airport following a separation occurrence involving an Airbus A320-232 and a Jabiru that took place on 28 November 2020 (see investigation AO-2020-062).

Human factors

The ATSB investigation considered a range of human factors that could have influenced the decisions and actions of the pilots and controller involved. No indicators that increased the risk of any of the individuals experiencing a level of fatigue known to influence performance were found. The following factors, however, were found to have possibly had an influence:

• shared mental models
• situation awareness
• confirmation bias

Mental models

According to Methieu et al (2000), mental models are internally organised knowledge structures that allow individuals to understand and interact with their environment. Mental models are said to be ‘shared’ when the models of individuals overlap – the greater the overlap the greater the similarity of understanding.

In scenarios involving the movement of aircraft within the airspace system, it is anticipated that pilots and air traffic controllers will have a high degree of shared mental model overlap. However, when communication is ineffective, and critical information and assumptions are not shared, the degree of shared mental model overlap is decreased, coordinated decision making is degraded, and safety defences are eroded (Bearman et al 2010).

The mismatch of mental models was evident in the lead up to this incident. Critical traffic information and assumptions were not shared between the SFIS controller, the Caravan pilot, and the B737 flight crew. This resulted in each party holding a different mental model of the traffic scenario.

Situation awareness

Situation awareness (SA) is best conceptualised as a 3-stage process:

1. task related features or cues are acquired and interpreted by the individual
2. information is integrated and comprehended within the context of the task to derive meaning for the individual
3. the individual anticipates the future state of the system (Wiggins 2022)

The accuracy of an individual’s SA directly influences their decisions.

The SFIS controller, the Caravan pilot and the B737 flight crew all held incomplete information on the traffic scenario and the intended actions of the others involved. As a result, their capacity to accurately predict the future traffic state was compromised and their decision-making impacted accordingly.

Confirmation bias

Confirmation bias involves an individual seeking out information that confirms an assumption and rejecting, ignoring, or explaining away information that conflicts with the held assumption (Wiggins 2022). Based primarily on their assessment of the windsock, the Caravan’s pilot incorrectly believed that the B737 was on final approach for runway 06 and not runway 24. It is therefore possible that the pilot’s confirmation bias influenced the visual check before entering the runway with the B737 on final approach from the opposite direction going undetected.

Safety analysis

The incident

On 16 September 2021, a Boeing 737, VH-YIO (B737), was approaching runway 24 to land at Ballina Byron Gateway Airport when a Cessna Caravan 208, VH-YMV (Caravan), commenced a take-off on the reciprocal runway. The B737’s flight crew conducted a missed approach during which the lateral separation between the 2 aircraft decreased to approximately 0.9 NM with vertical separation reducing to about 700 feet. At the time of the incident, the aircraft were operating within the airport’s broadcast area, and both were receiving the associated surveillance flight information service (SFIS).

Communications

The SFIS controller had not included the B737’s estimated time of landing and runway direction when providing traffic information to the Caravan pilot. In addition, the Caravan pilot had formed the belief that the B737 would land on runway 06 (based on observing the runway windsock), and then interpreted the traffic information provided by the controller incorrectly as it confirmed their incorrect mental model. The pilot did not seek to validate this assumption by communicating directly with the B737’s flight crew or by querying the information provided by the controller.

The scenario was further compounded by the B737’s flight crew not hearing the Caravan’s taxi broadcasts or the SFIS controller’s responses. Those taxi transmissions commenced 40 seconds before the B737 turned onto final approach for runway 24. The ATSB was not able to determine why the flight crew did not hear the exchange. In any case, they were not aware of the Caravan until the ‘entering and rolling’ broadcast made by its pilot.

The SFIS controller knew the B737’s flight crew had not acknowledged the Caravan pilot’s taxi broadcast but recalled from SFIS training that follow-up communications were not necessary for aircraft already on the common traffic advisory frequency (CTAF). Consequently, the controller decided not to confirm that the flight crew were aware of the Caravan, and an opportunity to address the evolving situation was missed. This resulted in the B737’s flight crew remaining unaware of the Caravan and the latter’s pilot continued to incorrectly believe the B737 would land in the opposite direction.

The Caravan pilot’s incorrect mental model also led them to believe the Caravan could take-off ahead of the landing B737, using runway 06, without any conflict. The pilot recalled conducting a visual check prior to entering the runway; however, their likely confirmation bias and reduced situation awareness possibly resulted in not sighting the approaching B737. Consequently, the Caravan was taxied onto the runway and a take-off commenced directly towards the B737.

Safety alert

The SFIS controller recognised the impending conflict between the two aircraft after hearing the Caravan pilot’s ‘entering and rolling’ broadcast but decided not to issue a safety alert because of concerns of over transmitting communications from the Caravan or the B737. However, between the ‘entering and rolling’ broadcast and confirmation that the Caravan pilot had sighted the B737, there was a total of 53 seconds during which time no transmissions were made on the CTAF. A safety alert issued during this time would probably have ensured the pilots on both aircraft were fully aware of the conflict.

Surveillance coverage limitations

Prior to the implementation of the Ballina Airport SFIS, Airservices Australia had identified a hazard associated with a critical component of the service that could lead to unintended aircraft proximity events. As the secondary surveillance radar and automatic dependent surveillance broadcast (ADS-B) coverage near the airport did not commence until about 1,500 feet above ground level, ADS-B equipped aircraft operating below this height may not be displayed on the SFIS controller’s console screen. Airservices Australia formally accepted the risk associated with the surveillance coverage limitations and the SFIS was implemented with this critical component compromised. 

The limitation in coverage resulted in the SFIS controller having no positional information on the Caravan during the period of conflict until the aircraft reached an altitude of about 1,500 feet about 100 seconds after taking off. During this period, the controller was solely reliant on radio communications for situation awareness and had reduced options for providing any avoidance advice necessitated by the situation.

The heightened risk of separation incidents in the vicinity of Ballina Airport was identified in the Civil Aviation Safety Authority’s (CASA’s) Ballina airspace review, which was published in December 2022. Recommendations contained in that review document included the installation of an automatic dependent surveillance broadcast (ADS-B) ground station in the vicinity of Ballina Airport to enable ADS-B surveillance capability to the runway surface. The review document contained 8 other recommendations designed to incrementally transition Ballina Airport to a controlled aerodrome service with an associated control zone and control area steps by 13 June 2024. Such an aerodrome control service would have prevented the traffic conflict between the B737 and the Caravan.

Both this separation occurrence and that detailed in AO-2020-062 involved high-capacity transport aircraft using the primary defence of alerted see‑and‑avoid. Noting the known limitations of this principle, and the increasing and complex mix of traffic, the ATSB considers that timely implementation of the recommendations detailed in CASA’s airspace review document would significantly improve safety at Ballina Airport.

Findings

From the evidence available, the following findings are made with respect to the separation occurrence involving Boeing 737-8FE, VH-YIO (B737) and Cessna Caravan 208, VH-YMV (Caravan) at Ballina Byron Gateway Airport, New South Wales on 16 September 2021.

Contributing factors

• Based on an assessment of the windsock only, the Caravan pilot wrongly assumed that the B737 would land behind them on runway 06 and not present a conflict for their departure. This incorrect mental model of the traffic was not corrected prior to the conflict as the surveillance flight information service controller did not specify that the B737 would land on runway 24 and the pilot did not confirm the runway direction with the controller or with the B737’s flight crew.
• The B737’s flight crew did not hear the Caravan pilot’s taxi broadcast or the surveillance flight information service controller's response, who also did not confirm if the flight crew were aware of the Caravan. Consequently, the flight crew was unaware of the Caravan until its pilot made a broadcast before entering the runway.
• The visual check by the Caravan’s pilot before entering the runway did not identify the B737 on final approach to land on runway 24, possibly due to confirmation bias and degraded situation awareness resulting from the pilot’s incorrect mental model of the traffic.
• The Caravan’s pilot commenced a take-off directly towards the approaching B737 resulting in its flight crew conducting a missed approach to avoid the Caravan.

Other factors that increased risk

• The surveillance flight information service controller did not issue a safety alert after the Caravan entered the runway and commenced taking off towards the approaching B737 due to concerns that issuing an alert would result in over transmitting communications from either aircraft.
• The surveillance flight information service (SFIS) had been implemented in an area with known surveillance coverage limitations, resulting in the SFIS controller having no displayed positional information for the Caravan until it reached an altitude of about 1,500 feet. Therefore, during the period of conflict between the Caravan and B737, the controller was solely reliant on radio communications for situation awareness, reducing their ability to provide appropriate traffic and avoidance advice. (Safety issue)

Safety issues and actions

SFIS surveillance coverage

Safety issue number: AO-2021-038-SI-01

Safety issue description: The surveillance flight information service (SFIS) had been implemented in an area with known surveillance coverage limitations, resulting in the SFIS controller having no displayed positional information for the Caravan until it reached an altitude of about 1,500 feet. Therefore, during the period of conflict between the Caravan and B737, the controller was solely reliant on radio communications for situation awareness, reducing their ability to provide appropriate traffic and avoidance advice.

Glossary

ADS-B              Automatic dependant surveillance broadcast

AMSL               Above mean sea level

ATPL                Air transport pilot licence

BA                    Broadcast area

CA/GRO           Certified air/ground radio operator

CA/GRS            Certified air/ground radio service

CTAF                Common traffic advisory frequency

FO                    First officer

GPS                 Global positioning systems

IFR                   Instrument flight rules

KM                   Kilometres

NM                   Nautical miles

NSW                 New South Wales

PF                    Pilot flying

PM                   Pilot monitoring

SA                    Situation awareness

SFIS                 Surveillance flight information service

SSR                 Secondary surveillance radar

VFR                  Visual flight rules

Sources and submissions

Sources of information

The sources of information during the investigation included:

• the flight crew of VH-YIO and pilot of VH-YMV
• the SFIS controller
• Virgin Airlines Australia
• Avdata
• OzRunways
• Civil Aviation Safety Authority
• Airservices Australia
• Bureau of Meteorology
• Experience Co Limited

References

Wiggins M 2022, Introduction to human factors for organisational psychologists, Taylor & Francis Group, Milton

Bearman C, Paletz S, Orasanu J & Thomas M 2010, The breakdown of coordinated decision making in distributed systems, Human factors, Vol. 52, pp. 173-188

Mathieu J, Heffner T, Goodwin G, Salas E & Cannon-Bowers J 2000, The influence of shared mental models on team process and performance, Journal of applied psychology, vol 85, pp. 273

Submissions

Under section 26 of the Transport Safety Investigation Act 2003, the ATSB may provide a draft report, on a confidential basis, to any person whom the ATSB considers appropriate. That section allows a person receiving a draft report to make submissions to the ATSB about the draft report.

A draft of this report was provided to the following directly involved parties:

• the flight crew of VH-YIO and pilot of VH-YMV
• the SFIS controller
• Virgin Airlines Australia
• Airservices Australia
• Experience Co Limited
• Civil Aviation Safety Authority.

Submissions were received from:

• Airservices Australia
• Experience Co Limited
• Civil Aviation Safety Authority.

The submissions were reviewed and, where considered appropriate, the text of the report was amended accordingly.

Purpose of safety investigations The objective of a safety investigation is to enhance transport safety. This is done through: identifying safety issues and facilitating safety action to address those issues providing information about occurrences and their associated safety factors to facilitate learning within the transport industry. It is not a function of the ATSB to apportion blame or provide a means for determining liability. At the same time, an investigation report must include factual material of sufficient weight to support the analysis and findings. At all times the ATSB endeavours to balance the use of material that could imply adverse comment with the need to properly explain what happened, and why, in a fair and unbiased manner. The ATSB does not investigate for the purpose of taking administrative, regulatory or criminal action. Terminology An explanation of terminology used in ATSB investigation reports is available here. This includes terms such as occurrence, contributing factor, other factor that increased risk, and safety issue. Publishing information  Released in accordance with section 25 of the Transport Safety Investigation Act 2003 Published by: Australian Transport Safety Bureau © Commonwealth of Australia 2023 Ownership of intellectual property rights in this publication Unless otherwise noted, copyright (and any other intellectual property rights, if any) in this report publication is owned by the Commonwealth of Australia. Creative Commons licence With the exception of the Coat of Arms, ATSB logo, and photos and graphics in which a third party holds copyright, this publication is licensed under a Creative Commons Attribution 3.0 Australia licence. Creative Commons Attribution 3.0 Australia Licence is a standard form licence agreement that allows you to copy, distribute, transmit and adapt this publication provided that you attribute the work. The ATSB’s preference is that you attribute this publication (and any material sourced from it) using the following wording: Source: Australian Transport Safety Bureau Copyright in material obtained from other agencies, private individuals or organisations, belongs to those agencies, individuals or organisations. Where you wish to use their material, you will need to contact them directly.

Executive summary

What happened

On 3 September 2021, a Boeing Company 737-8FE (B737), registered VH-YIS and operated by Virgin Australia, was conducting a flight from Melbourne, Victoria, to Darwin, Northern Territory. During the pre-flight briefing, the flight crew planned the incorrect displaced threshold instrument approach into Darwin Airport. During the approach, air traffic control cleared the flight crew for a non-displaced threshold approach but the flight crew continued and conducted the pre‑planned displaced threshold approach and landing. The aircraft landed 1,153 m into the runway.

Separately, on 19 September 2021 a Boeing Company 737-81D (B737), registered VH-YFC and also operated by Virgin Australia, conducted a flight from Brisbane, Queensland to Darwin, Northern Territory. During the pre-flight briefing the flight crew similarly planned a displaced threshold approach into Darwin runway 11 instead of the non‑displaced threshold approach. The aircraft landed 932 m into the runway.

What the ATSB found

The ATSB found that the flight crew of VH-YIS misinterpreted the notice to airmen (NOTAM) information during the pre-flight briefing which led them to believe that runway 11 was displaced. As a result, they planned for the displaced threshold approach on runway 11. The flight crew continued the planned runway 11 VOR-T despite being cleared for the non‑displaced threshold runway 11 VOR-Z approach by air traffic control.

This resulted in reduced runway length being available for the landing roll. Air traffic control did not request the flight crew to correctly readback the VOR approach clearance resulting in a missed opportunity to identify the error and for the flight crew to reconsider their decision to continue the displaced threshold approach.

The flight crew of VH-YFC similarly misinterpreted the NOTAM during pre-flight briefing which led them to believe that both ends of 11/29 in Darwin were displaced. This resulted in the flight crew planning for and conducting the RWY 11 VOR-T displaced threshold approach instead of the RWY 11 VOR-Z non-displaced threshold approach.

Both flight crews misinterpreted the Darwin Airport recorded information prior to arrival, this also resulted in a missed opportunity to capture the misidentification of the displaced threshold information from the NOTAM.

What has been done as a result

After the first incident, Virgin Australia updated their Flight Crew Operational Notice to reflect that the Darwin Airport runway 11 works had been completed, and then subsequently modified it further after the second occurrence to specifically highlight the displaced thresholds.

Safety message

Operational information in a NOTAM, can have critical importance for the planning and conduct of a flight. As such, misinterpretation of this information can significantly affect flight safety.

Correct and complete readback of air traffic control clearances, are important to confirm that information has been received and understood and provide a valuable defence to detect and correct errors such as occurred during these incidents.

Finally, when there is uncertainty or ambiguity about the condition of a destination, such as a displaced threshold, flight crew are encouraged to seek clarification from air traffic control.

The investigation

The occurrence

On 3 September 2021 at about 0945 Eastern Standard Time (EST)[1] the flight crew of a Boeing Company 737-8FE (B737), registered VH-YIS (YIS) and operated by Virgin Australia, were conducting their pre-flight briefing on the flight deck in preparation for flight VA1457 from Melbourne, Victoria, to Darwin, Northern Territory. The flight crew consisted of a captain and a first officer.

The flight crew reported that they both reviewed a NOTAM[2] for Darwin (Figure 1) during the pre‑flight briefing and acknowledged to each other that there were runway works in progress that reduced the available runway length. The flight crew also reviewed the Flight Crew Operational Notice (FCON)[3] for Darwin (Figure 4). The captain commented that they were aware of the reduced runway length for Darwin and the first officer commented that they were both under the impression that runway 11 had a displaced threshold and not runway 29 as the NOTAM stated.

The flight crew received the ATIS[4] (Figure 2) during cruise and then commenced an arrival brief 30 minutes before the planned top of descent. The flight crew planned to conduct the Darwin runway 11 VOR-T instrument approach associated with a displaced runway 11 threshold (Figure 7) and they calculated the landing distance based on that displacement.

At 1436 Central Standard Time (CST)[5] air traffic control instructed VA1457 to descend to 9,000 ft and they were subsequently cleared for the runway 11 VOR-Z instrument approach (Figure 6).The flight crew, cognisant that they had planned for the VOR-T in expectation of a runway 11 displaced threshold, discussed with each other that air traffic control had cleared them for the VOR-Z approach. The flight crew, believing that the VOR-T was safe and appropriate, elected to continue and not conduct the VOR-Z approach in accordance with their clearance.

The aircraft touched down 1,153 m into the runway and the aircraft decelerated to a stop before the displaced threshold cones that were present at the 29 displaced threshold. The aircraft backtracked on the runway and taxied to the terminal. Having recognised the error, the flight crew reported their misinterpretation of the displaced threshold to Virgin Australia.

On 19 September 2021, the flight crew of a Boeing Company 737-81D (B737), registered VH-YFC (YFC) and also operated by Virgin Australia, were conducting their pre-flight briefing for flight VA449 from Brisbane, Queensland to Darwin, Northern Territory. The flight crew consisted of a captain and a first officer.

During the pre-flight briefing, the flight crew reviewed the NOTAM (Figure 1) and the company supplied briefing pack. The captain commented that they believed the NOTAM and FCON were ambiguous regarding the displaced runway threshold and expected to acquire more information in flight when they received the ATIS (Figure 3). The flight departed at 0944 EST.

Prior to the top of descent into Darwin, the flight crew received the ATIS and commenced their arrival brief. They discussed that there was no information on the ATIS broadcast regarding displaced thresholds, and decided to conduct the displaced threshold VOR-T approach just in case the threshold was displaced. The flight crew also commented that if the PAPI[6] was operating that it would read high while on approach to runway 11.

The flight crew conducted the Darwin runway 11 VOR-T approach and touched down 932 m down the runway, decelerated, and proceeded to the terminal. During the taxi to the terminal, the captain noted the displaced threshold cones at the 29 end of the runway and realised that a misinterpretation of the NOTAM had occurred. The flight crew reported the occurrence to Virgin Australia.

Context

Information available to flight crew

Both flight crews conducted a briefing prior to dispatch from their departure airports. The information included in these briefings was provided to them by Virgin Australia in the FCON and in a pilot briefing pack that was prepared for each flight. The briefing packs contained information such as the flight plan, weather, and fuel requirements. They also contained the NOTAMs of the departure and destination airports, as well as information on en-route airports, in case a diversion was required. The briefing pack provided to the crew of YFC included a note from the Virgin Australia dispatcher indicating that Darwin runway 29 has a displaced threshold.

Notice to airmen

For both occurrences, information related to displaced thresholds in the Darwin NOTAM (Figure 1) was the same. The NOTAM stated that runway 29 had a displaced threshold of 765 m due to works in progress and that the eastern end of runway 11/29 was not available due to the works. The NOTAM also stated that the landing distance available on runway 11, with the runway 29 threshold displaced, was 2,670 m.

Figure 1: Darwin NOTAM, current at the time of both occurrences

Source: Virgin Australia, annotated by ATSB

The captain of YIS stated that when they reviewed the NOTAM during the pre-flight briefing the reduced length of the runway was all that they comprehended. The captain did not review the NOTAM again until after the occurrence. The first officer reviewed the NOTAM twice before departure, once at home and once during the pre-flight briefing with the captain. The first officer stated that, after the pre-flight briefing, they were both under the impression that the threshold of runway 11 was displaced.

The captain of YFC recalled that, after reviewing all the available information during the pre-flight briefing, their interpretation was that both thresholds of runway 11/29 were displaced. The captain stated that the 11 VOR-T was planned with an expectation to gather further information regarding the displaced thresholds when the ATIS was received in flight.

The flight crew of YIS, and the captain of YFC, recalled reviewing the NOTAM after their flights and realising that a misinterpretation of the displaced threshold had taken place.

Automatic terminal information service

In both occurrences the ATIS was received in flight via the ACARS[7] prior to the conduct of the arrival briefings. The ATIS received on 3 September (Figure 2) by the flight crew of YIS, stated that runway 11 and 36 was to be used for arrivals and departures. It also noted that runway 11 had a reduced runway length. The first officer commented that after reviewing the ATIS they conducted the arrival briefing with the impression that runway 11 had a displaced threshold rather than a section of the upwind end of the runway being unavailable.  

Figure 2: ATIS utilised by flight crew of YIS on 3 September 2022

Source: Virgin Australia, annotated by ATSB

The ATIS received on the 19 September (Figure 3) by the flight crew of YFC, stated that runway 11 was in use and that runway 11 had a reduced runway length. The captain commented that the ATIS only mentioned a reduced runway length on runway 11 and not a displaced threshold, therefore they continued with the planned runway 11 VOR-T approach. No clarification was sought from air traffic control on either occasion.

Figure 3: ATIS utilised by flight crew of YFC on the 19 September 2022

Source: Virgin Australia, annotated by ATSB

Flight Crew Operational Notice

The FCONs were provided to both flight crews as part of the flight briefing pack. On the 3 September 2021 the FCON (Figure 4) provided the following information:

• From 25 February 2021 until 30 September 2021, RWY 11/29 is undergoing works associated with upgrading the Aircraft Arrestor System.
• During works, RWY 11 threshold and RWY 29 threshold will be displaced at separate times.
• Actual date and time of works and threshold displacements will be advised by NOTAM.

The FCON also stated the specific VOR instrument approach chart to use

Figure 4: Flight Crew Operational Notice used by VH-YIS on the 3 September 2022

Source: Virgin Australia, annotated by Virgin Australia

Following the occurrence on the 3 September, the FCON (Figure 5) was updated by Virgin Australia on the 16 September with the following amendment:

• During the works RWY 29 threshold will be displaced, and runway operational length of both RWY 11 and 29 will be reduced.

Figure 5: Flight Crew Operational Notice used by VH-YFC on the 19 September 2022

Source: Virgin Australia

VOR Approaches

Darwin runway 11 had 2 published VOR procedures current at the time of the occurrences. The VOR-Z (Figure 6) and the VOR-T (Figure 7).

The VOR-Z RWY 11 approach was used when the runway did not have a displaced threshold. The aircraft was to be flown down a 3° approach path from an 8 nm final approach fix, indicated by the Maltese cross, from an altitude of 1,880 ft to a touch down point 300 m past the runway threshold.

Figure 6: VOR-Z non-displaced threshold approach

Source: Airservices Australia, annotated by ATSB

The VOR-T RWY 11 approach was to be used when the threshold was displaced 723 m due to runway works. The VOR-T placed the aircraft 130 ft higher at the final approach fix, indicated by the Maltese cross, The aircraft was to be flown down a 3° approach path from an 8 nm final approach fix altitude of 2,010 ft to a touch down past the displaced runway threshold.

Figure 7: VOR-T displaced threshold approach

Source: Airservices Australia, annotated by ATSB

Air traffic control readback requirements

Aeronautical Information Package Australia ENR 1.1-15, 2.11.2.5 stated:

The full chart title of the instrument approach procedure, as described at the top of the relevant chart, must be used in all clearances, coordination and readbacks relating to the procedure, including entry procedures. However, with the exception of circling approaches, the suffix may be omitted if there is no possibility of confusion. Where multiple approach procedures are on the same chart, only the approach procedure being conducted shall be referred to.

On the 3 September occurrence, air traffic control (ATC) cleared the crew of YIS to conduct the VOR-Z approach. The captain responded ‘cleared the 11 VOR but did not use the suffix of Zulu or Tango. ATC did not request the captain to readback the suffix.

For the 19 September occurrence, the captain reported that air traffic control only cleared YFC for the 11 VOR with no suffix. This could not be verified as the ATC recording was not available.

Recorded information

Flight parameters for the approach were recorded by both aircraft and were provided to the ATSB. This data included the:

• aircraft height above the airfield
• ground speed
• rate of descent in feet per minute
• angle of descent in degrees
• touchdown point of aircraft
• brake pressure
• engine settings.

On the 3 September 2021, the flight data indicated that:

• YIS touched down 1,153 m into the runway at a groundspeed of 139 kt
• 1.25 seconds later the auto brakes activated (1,256 m into the runway)
• 7 seconds after the touchdown, reverse thrust was selected (1,606 m into the runway)
• reverse thrust was active until a groundspeed of 43 kt
• peak manual braking occurred from a groundspeed of 37 kt to 19 kt.
• YIS turn around on the runway prior to the unusable area and taxied to the terminal

On the 19 September 2021, the flight data indicated that:

• YFC touched down 932 m into the runway at a groundspeed of 137 kt
• auto braking was active until a groundspeed of 98 kt
• reverse thrust was active until a groundspeed of 58 kt
• YFC exited via a taxiway and taxied to the terminal.

Safety analysis

Introduction

In September 2021, on 2 separate occasions, Virgin Australia flight crews planned and conducted a displaced threshold approach and landing on runway 11 at Darwin Airport. At the time of the occurrences runway 11 was not subject to a displaced threshold, although, at the opposite end on runway 29, a displaced threshold was in place due to works being undertaken.

Flight information

NOTAM information indicated that the eastern end of runway 11/29 was not available due to the works and, as a result, the threshold of runway 29 was displaced. The flight crew of YIS misinterpreted this section of the NOTAM and concluded that runway 11 had a displaced threshold and planned the VOR-T displaced threshold approach for runway 11.

The flight crew of YFC similarly misinterpreted the NOTAM, concluding that both ends of the runway were simultaneously displaced. As a result, they planned for a displaced threshold on runway 11, with an intention to await further information contained in the ATIS.  

The FCON used by the flight crew of YIS stated that the runway 11 threshold and runway 29 threshold were displaced at separate times. The FCON also directed the flight crew to refer to NOTAM information to identify which runway threshold was displaced during flight planning. The FCON detailed the correct VOR chart to use when the thresholds were displaced. The flight crew, with this information from the FCON, in conjunction with a misinterpretation of the NOTAM that runway 11 threshold was displaced, planned the runway 11 VOR-T displaced threshold approach.

An updated version of the FCON, which contained information that the threshold of runway 29 was displaced, was provided to the flight crew of YFC. As the threshold of runway 11 was not displaced at the time, the FCON did not provide any information on runway 11 other than stating that the operational length of both runway 11 and 29 was reduced. The flight crew did not identify that the reduced length of runway 11 was due to the works underway at the upwind end of the runway. As a result, the flight crew planned the displaced threshold approach to runway 11 with an intention to await the reception of the ATIS for further information.

Due to the succinct nature and purpose of an ATIS, the Darwin ATIS only referenced the runway in use at the time, which was runway 11. As runway 11 was not subject to a displaced threshold, the ATIS only informed of its reduced length.

The flight crews of YIS and YFC continued with their plan to conduct the VOR-T displaced threshold approach in both instances. The captain of YFC commented that the ATIS was expected to provide further information in flight on the status of the runway, but no further information was obtained from the ATIS. There was no attempt by the flight crews to contact ATC for clarification on either occasion.

ATC cleared the flight crew of YIS to conduct runway 11 VOR-Z, non-displaced threshold approach. This approach clearance was unexpected by the flight crew as they had planned the VOR-T displaced threshold approach. The flight crew decided to continue with their planned displaced threshold approach without advising ATC. The captain responded to ATC with ‘cleared runway 11 VOR’ but omitted the suffix ‘Zulu’.  ATC did not request the flight crew to read back the suffix as required. A readback request by ATC may have presented an opportunity for the flight crew to identify the error.

It is likely that, due to both flight crew’s initial misinterpretation of a displaced threshold from the NOTAM information, any further information that was provided by the FCON and the ATIS was viewed with a perception that the threshold of runway 11 was displaced. As a result, the flight crew of YIS did not realise the misinterpretation until ATC cleared them for the VOR-Z approach. The flight crew of YFC did not realise their misinterpretation until after landing.

Findings

From the evidence available, the following findings are made with respect to the NOTAM misinterpretations at Darwin Airport on the 3 and 19 September 2021.

Contributing factors

• The flight crew of VH-YIS misinterpreted Darwin airport information during pre-flight briefing, which resulted in them believing that the threshold of runway 11 in Darwin was displaced. This subsequently resulted in the flight crew planning for and conducting the RWY 11 VOR-T displaced threshold approach instead of the RWY 11 VOR-Z standard approach.
• The flight crew of VH-YIS continued the planned runway 11 VOR-T approach despite being cleared for the runway 11 VOR-Z approach by air traffic control. This resulted in reduced runway available for the landing roll.
• The flight crews of VH-YIS and VH-YFC misinterpreted, or did not comprehend, the information on the ATIS prior to arrival. This resulted in a missed opportunity to capture the misidentification of a displaced threshold and the continuation of the VOR-T approach.
• The flight crew of VH-YFC misinterpreted Darwin Airport information during pre-flight briefing which led them to believe that both ends of 11/29 in Darwin were displaced. This resulted in the flight crew planning for and conducting the RWY 11 VOR-T displaced threshold approach instead of the RWY 11 VOR-Z standard approach.

Other factors that increased risk

• Air traffic control did not request the flight crew of VH-YIS to fully readback their VOR approach clearance. This was a missed opportunity for the error to be identified and the flight crew to reconsider their decision to continue with the planned VOR-T approach.

Safety actions

Safety action by Virgin Australia

Following the occurrence on the 3 September 2022, Virgin Australia modified their Flight Crew Operational Notice (FCON) for Darwin Airport to remove the runway 11 displaced threshold information, and then subsequently modified the FCON further after the second occurrence to specifically highlight the displaced thresholds.

Sources and submissions

Sources of information

The sources of information during the investigation included:

• Virgin Australia
• the flight crews of VH-YFC and VH‑YIS
• RAAF air traffic control
• Airservices Australia
• Civil Aviation Safety Authority

Submissions

Under section 26 of the Transport Safety Investigation Act 2003, the ATSB may provide a draft report, on a confidential basis, to any person whom the ATSB considers appropriate. That section allows a person receiving a draft report to make submissions to the ATSB about the draft report.

A draft of this report was provided to the following directly involved parties:

• Virgin Australia
• the flight crews of VH-YFC and VH-YIS
• RAAF air traffic control
• Civil Aviation Safety Authority

No draft report submissions were received.

Purpose of safety investigations The objective of a safety investigation is to enhance transport safety. This is done through: identifying safety issues and facilitating safety action to address those issues providing information about occurrences and their associated safety factors to facilitate learning within the transport industry. It is not a function of the ATSB to apportion blame or provide a means for determining liability. At the same time, an investigation report must include factual material of sufficient weight to support the analysis and findings. At all times the ATSB endeavours to balance the use of material that could imply adverse comment with the need to properly explain what happened, and why, in a fair and unbiased manner. The ATSB does not investigate for the purpose of taking administrative, regulatory or criminal action. Terminology An explanation of terminology used in ATSB investigation reports is available here. This includes terms such as occurrence, contributing factor, other factor that increased risk, and safety issue. Publishing information  Released in accordance with section 25 of the Transport Safety Investigation Act 2003 Published by: Australian Transport Safety Bureau © Commonwealth of Australia 2023 Ownership of intellectual property rights in this publication Unless otherwise noted, copyright (and any other intellectual property rights, if any) in this report publication is owned by the Commonwealth of Australia. Creative Commons licence With the exception of the Coat of Arms, ATSB logo, and photos and graphics in which a third party holds copyright, this publication is licensed under a Creative Commons Attribution 3.0 Australia licence. Creative Commons Attribution 3.0 Australia Licence is a standard form licence agreement that allows you to copy, distribute, transmit and adapt this publication provided that you attribute the work. The ATSB’s preference is that you attribute this publication (and any material sourced from it) using the following wording: Source: Australian Transport Safety Bureau Copyright in material obtained from other agencies, private individuals or organisations, belongs to those agencies, individuals or organisations. Where you wish to use their material, you will need to contact them directly.

Executive summary

What happened

On 17 September 2021, intermodal freight train 8796, operated by Aurizon, was en route from the Stuart terminal (near Townsville) to Brisbane, Queensland. One of the wagons was loaded with a flat rack carrying a heavy road vehicle tipping trailer that was out of gauge (over the permissible height for the route).

During the journey, the trailer’s hydraulic lifting post collided with the overhead structure of Alexandra Bridge in Rockhampton, causing damage to the bridge and trailer. There were no injuries and no damage to the train.

What the ATSB found

The Stuart terminal was an intermodal freight facility that was cooperatively operated between Linfox and Aurizon. Linfox was responsible for the movement of road freight to and from the terminal, and owned the wagons. Aurizon conducted the loading of rail wagons at the terminal and was responsible for rail operations and rail safety, including the safety and integrity of loads.

The tipping trailer was a Linfox asset rather than customer freight. As such, it was not managed through Linfox’s normal process, which required any non-standard loads to be referred to management for approval. The Linfox capacity officer who entered the load into the freight management system was not advised that the trailer was a tipping trailer and, as a result, it was entered into the system with generic, incorrect dimensions and with no indication of it being potentially out-of-gauge. In addition, unlike at other terminals where Linfox was directly involved in loading trains, Linfox did not have a process for internal, non-standard freight movements at the Stuart terminal to be reviewed and approved for conformance to the permissible loading profile for transport via rail.

The tipping trailer was secured onto a flat rack by Linfox staff, and then lifted onto the wagon by an Aurizon heavy lift operator. The heavy lift operator misjudged the height of the freight when loading the wagon, likely associated with the heavy lift operator not having any nearby reference objects and having a high level of expectancy that the load would not be out of gauge (given that non-standard loads were rarely encountered and there had been no prior indication that this load would be out of gauge).

Later, while conducting a walking inspection of the completed consist, the heavy lift operator did not detect the over-height load, probably due to expectancy and being focussed on checking that the loads were secure rather than their height. Similarly, the out-of-gauge load was not detected during 2 subsequent roll-by inspections (one at Stuart and one at Merinda).

At the Stuart terminal, Aurizon did not routinely apply a process to verify that the dimensions of non-standard loads were within the permissible loading profile. Aurizon had previously had a tool for measuring the height of loads at the terminal. However, at the time of the occurrence, it did not have any measuring equipment available to identify freight loads that were outside the permissible loading profile for transport via rail.

What has been done as a result

Aurizon reported that it carried out a range of safety actions as a result of this occurrence, including:

• installing a passive over-height warning device (jangle bar) as temporary corrective action, and initiating assessment in relation to automated controls
• updating its freight management system and booking system and implementing procedures for the identification of non-standard freight
• revising competency assessments for forklift and reach stacker operators
• reviewing its loading and securing training and standards.

Linfox advised that it would train forklift and operations staff in Aurizon loading and securing and produce a quick reference guide for loaders, and it arranged for non-standard items to be referred to and approved by the capacity and rail network manager.

Safety message

In the absence of measuring equipment, or nearby objects of a known and relevant height, it is difficult to accurately estimate the dimensions of loaded freight, especially when judging the height of tall freight from ground level. Tools to alleviate this limitation will be significantly more accurate and come with minimal cost and should be available to personnel involved in loading non-standard loads.

The occurrence

Freight arrangements

Intermodal freight train 8796, operated by Aurizon, was a regular service between Stuart (near Townsville) to Acacia Ridge (in Brisbane), Queensland on the North Coast Line (Figure 1). At the Stuart terminal, Aurizon was responsible for the loading of freight onto wagons and Linfox was responsible for the movement of road freight to and from the terminal. Queensland Rail (QR) was the rail infrastructure manager for most of the North Coast Line.

Figure 1: Shipping route

Source: Queensland Rail, annotated by ATSB

On 15 September 2021, the Linfox warehouse supervisor at the Stuart terminal made a request (via phone) to a Linfox capacity officer at Acacia Ridge for a (heavy road vehicle) trailer to be transported via rail from Stuart to Brisbane.

The trailer was a tipping skeletal trailer (Figure 2) that was designed to be towed by a prime mover for transporting shipping containers via road, with the capability of raising one end to unload its contents. It had an incorporated hydraulic lifting post to facilitate the tipping process. The height of the tipping trailer, including the hydraulic lifting post, was 3.070 m. The trailer was a Linfox asset based at the Stuart terminal and it was being transported to be used by Linfox at the Acacia Ridge terminal.

Figure 2: Tipping skeletal trailer dimensions

All measurements are in mm. Shown attached to a prime mover and loaded with a 20-foot container.

Source: Aurizon

The Linfox capacity officer entered the trailer into Aurizon’s A2B freight management system for rail transport. It was entered in the system as a flat rack unit,[1] with a length of 12.192 m and height of 2.743 m, which was the default height in the A2B system. It was classified as ‘general domestic’ freight.

The flat rack type used for the trailer was common to the freight operation, and it had a height 0.260 m. The total height above the wagon floor of the tipping trailer’s hydraulic lifting post on a flat rack was therefore 3.330 m. This was 0.590 m above the maximum permissible height of a load on the QR network.

In their conversation with the capacity officer, the Linfox supervisor did not describe the trailer as a tipping trailer and did not provide (and was not asked to provide) its dimensions. The capacity officer later stated that they were aware that the tipping version of the trailer was probably out of gauge,[2] but they had not been advised that this particular trailer was the tipping version. Accordingly, they thought they were arranging to transport a normal (non-tipping) trailer. They did not change the default dimensions of the load in the freight management system and the consignment note did not include an out-of-gauge warning or indication.

Loading and departure

At about 1150 local time on 16 September, Linfox personnel reversed the trailer with a prime mover onto a flat rack at the Stuart terminal and secured it for transport. A closed-circuit television (CCTV) recording showed that several Linfox personnel were involved in the loading process (Figure 3). The dimensions of the loaded flat rack were not measured during this process.

Figure 3: Loading and securing the tipping trailer on to a flat rack at Stuart Yard

Source: Aurizon

After the trailer was secured onto the flat rack, the Linfox supervisor notified an Aurizon heavy lift (forklift) operator that the trailer was ready to be loaded. At 1347, the heavy lift operator lifted the flat rack with the tipping trailer by forklift onto a flat rail wagon (number BCZY 46459). The load’s dimensions were not verified, and the heavy lift operator did not identify that the load was potentially out of gauge.

The wagons were then shunted onto the train. From 1740 to 1805, the heavy lift operator completed a test and inspection of the completed rail consist, including the wagon with the loaded trailer, checking for container and load security. The inspection was from an area beside the track with eye height below the top of the trailer. They did not identify that the load was potentially out of gauge during this process.

At 1912, train 8796 departed the Stuart terminal as a driver-only operation with a 2800 class locomotive. During the departure of the train, a roll-by inspection[3] was conducted by Aurizon personnel, which did not identify the over-height wagon.

At 2240, additional wagons were added at Merinda. A roll-by inspection at that location did not identify any problems.

A driver crew change occurred at Mackay and the train departed Mackay at 0225 on 17 September. On this section of the journey it had 26 container wagons and was 526 m long with a total weight of 1,164 t, and the consist was predominantly containerised freight and empty flat-bed wagons. The wagon carrying the trailer was the 23rd wagon.

Collision with Alexandra Bridge

At about 0723 on 17 September, the train entered the Alexandra Bridge structure, just outside of Rockhampton Yard, travelling at approximately 25 km/h. The Alexandra Bridge is a concrete pillar and steel truss bridge over a river located in the centre of Rockhampton, serviced by a single rail line and a pedestrian pathway.

Approximately 2 minutes later, the hydraulic lifting post on the trailer impacted the entry crossbeam of the bridge as its wagon passed onto the bridge (Figure 4). A CCTV recording showed the impact with the crossbeam at the northern end of the bridge causing damage to the girder and buckling of bridge braces. Additionally, the bracing rails on the trailer bent under the impact, forcing the hydraulic lifting post to bend backwards. This gave the trailer clearance under the bridge structure for the rest of its journey across the bridge.

Train 8796 continued to Rockhampton, with the driver unaware that the collision had occurred. At 0734 the train entered Rockhampton Yard.

Figure 4: Trailer collision with bridge

Source: Rockhampton Regional Council

Identification of the damaged trailer

The damaged tipping trailer was observed at Rockhampton Yard (Figure 5). The wagon was removed from the consist and QR was notified of the damage at about 1020.

At 1230, the rail traffic crew of Aurizon train 8798 reported damage to the overhead structure on Alexandra Bridge. QR track workers conducted an inspection of the rail corridor between Stuart and Rockhampton, and they determined that only Alexandra Bridge had been damaged (Figure 6). Rockhampton Regional Council confirmed the impact of the bridge through the review of a CCTV recording.

The bridge was deemed fit for the return of services by QR engineering personnel and reopened to rail traffic at 1530 on 17 September with a 10 km/h speed restriction, pending further assessment.

Figure 5: Damaged skeleton tipping trailer, Rockhampton Yard

Source: Aurizon (upper), Linfox (lower), annotated by the ATSB

Figure 6: Alexandra Bridge girder damage

Source: Queensland Rail, annotated by the ATSB

Context

Track and network information

The North Coast Line consists of 1,680 km of railway between Cairns and Brisbane. Queensland Rail (QR) was the rail infrastructure manager for about 1,567 km, including the section from Townsville to Rockhampton.

The maximum permissible load height on the on the North Coast Line from Townsville to Brisbane was 3.820 m above the rail, or 2.740 m above the wagon floor with a standard 1.080-m high wagon. Therefore, with a total height of 4.410 m, the wagon with the flat rack and tipping trailer was 0.590 m above the maximum permissible load height.  

Following the accident, QR measured the clearance between rail and the structure of Alexandra Bridge to be 4.312 m, which was 12 mm more than the bridge’s design clearance. Figure 7 compares the outline of a standard shipping container with the height of the Alexandra Bridge and the height of the tipping trailer’s hydraulic lifting post.

Figure 7: North Coast Line standard container loading outline[4] with overlays of tipping trailer and Alexandra Bridge beam heights

All measurements are in mm. The added Alexandra Bridge and tipping trailer height overlays are for illustrative purposes only.

Source: Aurizon, modified by ATSB

The track south of Rockhampton was electrified with sections of overhead contact wires as low as 4.349 m above the track level.

Stuart terminal

The Stuart terminal was an intermodal freight facility about 11 km south of Townsville that was cooperatively operated between Linfox and Aurizon. Linfox was responsible for the movement of road freight to and from the terminal and owned the wagons, with a ‘hook and pull’ (wagon hauling) agreement in place with Aurizon. Aurizon conducted the loading of rail wagons and was responsible for rail operations and rail safety, including the safety and integrity of loads. This arrangement meant that there was a combination of both Linfox and Aurizon personnel working at the terminal.

Most of the freight passing through Stuart Yard was in 20-foot or 40-foot containers, though occasionally non-containerised freight was also transported.

At the time of the occurrence, Aurizon was responsible for loading trains at Stuart and one other terminal on the North Coast Line. At other terminals (such as Acacia Ridge), Linfox was responsible for the loading.

Freight booking information

Aurizon and Linfox used a freight management system called A2B to coordinate the movement of items. 

Provisions were in place where freight known to be exceeding the standard outline could be transported. In those circumstances, when freight was known to be out of gauge, an authority to travel (ATT) authorisation was required to be obtained with specific restrictions (for example, only to travel through certain tracks or not to pass other rail traffic in certain areas). Even with an ATT in place, there was still maximum limitations due to various factors, such as tunnel sizes, overhead electrical equipment and bridges. Where an ATT was approved, the freight terminal would be advised directly, and a notation made on the consignment note applicable for the freight being transported, warning the loading operators of the oversized item.

Linfox reported that clients normally booked freight through its customer service team. Any non-standard freight bookings (or freight that did not fit into standard containers) would be referred to a manager for approval. In this case, however, the tipping trailer was an internal asset that was already in the yard at Stuart and the booking process bypassed this process. 

The Linfox warehouse supervisor at the Stuart terminal had only recently (within 3 months) commenced work at that terminal. They reported that they had arranged for the transport of tipping trailers by rail when working at another depot in another state, but had not previously arranged for transport of a tipping trailer from the Stuart terminal or on the North Coast Line.

Linfox advised that it had processes for checking the dimensions of freight at terminals where Linfox were involved in loading freight onto trains. However, since Linfox did not load freight onto rolling stock at the Stuart Terminal, there was no procedure in place for measurement of the dimensions of any non-standard freight received at the Stuart terminal prior to requesting Aurizon personnel to load the freight onto a train. The warehouse supervisor also advised that they were not aware of the specific dimensions of loads that were allowable on the North Coast Line. They were relying on the Aurizon personnel at the terminal to check the load and determine whether the load was suitable for rail travel. This was consistent with the process they were familiar with when working at other terminals.

Freight loading information

Aurizon’s Loading and Securing Standard provided instruction on the safe transport of different types of freight by rail or road throughout Australia. It noted that a rail infrastructure manager (RIM) was responsible for defining freight outlines and for the authorisation of out-of-gauge loads, and a rolling stock operator was responsible for ensuring freight complied with the RIM’s instructions. It also stated that, for rail transport, the rolling stock operator (in this case Aurizon) was responsible for ensuring:

• Loading that exceeds or infringes the permissible outlines applicable to the type of loading and the routes over which it will travel is not transported, unless it has a valid out of gauge certificate
• All loading that is suspected of being close to or outside the applicable outline is referred to the RIM for investigation

Aurizon’s Loading and Securing of Freight Manual emphasised that out-of-gauge loads were not allowed to travel on Aurizon trains without an ATT. It also stated that the workers responsible for loading and securing freight were responsible for (among other things) ensuring that freight was loaded so that its overall size was within the (specified) standard loading outlines. Aurizon provided such personnel with a checklist for loading and securing flat racks, which included the loading outline and maximum allowed dimensions.   

The Aurizon heavy lift (forklift) operator had worked in that role at the Stuart terminal for about 10 years, and they had undertaken the organisation’s online loading and securing training within the required time period. The heavy lift operator could not recall loading any out-of-gauge loads in the last 5 years. They stated they had knowledge of other (heavy road vehicle) trailers being transported on flat racks without any problems, and they also thought (but were not sure) that tipping trailers had been transported before. At the time they loaded this specific tipping trailer, they did not consider the height to be an issue. They had received no indication through the consignment note, their supervisor or the Linfox warehouse supervisor that the load was actually or potentially out of gauge. Other personnel who saw the loaded flat rack also indicated that they did not consider the height to be an issue.

Personnel reported that shipping containers were sometimes used as a general indication of the allowable freight envelope. On this occasion, although a 20-foot shipping container[5] was near the tipping trailer when it was loaded onto the flat rack by Linfox personnel, there was no container on the ground near the flat rack when it was lifted onto the wagon. The heavy lift operator also stated that there were no other containers on adjacent wagons at that time. There were containers loaded on the adjacent wagons when the completed rail consist was inspected at the Stuart terminal and at Merinda.

Aurizon advised the ATSB that pre-loaded flat racks that arrived at the terminal needed to pass an incoming inspection at the terminal’s entrance gate. However, it rarely received loaded flat racks via the entrance gate. Aurizon also advised that it was not a routine or consistent practice for the documented dimensions of non-standard freight to be physically verified, or for the train’s loading outline to be measured, during the loading process.

In addition, there were no tools or equipment provided for checking the dimensions of non-standard freight. Aurizon previously had a load height-measuring staff at Stuart to gauge a train’s height. This L-shaped staff or pole was held next to a wagon, and if the total load exceeded its height, that wagon would not be allowed to travel. This staff was a locally-implemented risk control; Aurizon’s safety management system did not specifically require it to be in place. After moving from previous facilities to the current Stuart terminal, the staff was no longer available to loading personnel.

The Stuart terminal did not have a viewing platform to assist with identifying out-of-gauge loads. There were also no other devices installed at the terminal to verify that loads were below the maximum permissible height or indicate over-height loads.

The ATSB has previously investigated a number of other occurrences involving loads out of gauge or not effectively secured. Some recent investigations include:

• On 15 June 2020, a wagon body became dislodged from the bogie during unloading at Coopers Plains, Queensland.[6] As part of the consist of train 2BW4, the wagon body later contacted and caused damage to platforms at Grafton, Coffs Harbour, Taree, Wingham and Dungong, New South Wales. The train had been inspected before departure, and again after damage to the Grafton platform was identified.
• On 18 August 2018, a collapsible rear end wall of a flat rack raised up en route and contacted an overpass on approach to Cooroy, Queensland, pulling down 1.3 km of high voltage overhead line equipment.[7] The ATSB found that personnel at the Acacia Ridge terminal did not check the collapsible end walls of the flat racks were secured on arrival at the terminal and after the flat racks were loaded. In addition, Aurizon, did not have an effective system in place for ensuring personnel required to check the securing of unusual loads (such as empty flat racks) prior to departure had sufficient knowledge of their responsibilities, and had ready access to relevant procedures, guidance and checklists.
• On 16 January 2018, an incorrectly-secured container on freight train 2BM9 collided with station infrastructure at Maitland, New South Wales, causing damage to gutter retaining brackets.[8] The investigation found that the departing train inspection did not detect the incorrectly-secured container, and that the collision with infrastructure was also partially due to raised track height at the station relative to the documented design. 

Findings

From the evidence available, the following findings are made with respect to the collision with infrastructure involving freight train 8796 at Rockhampton, Queensland, on 17 September 2021.

Contributing factors

• The dimensions of the tipping trailer were not entered correctly into the freight management system when the shipment was being arranged, and there was no indications that the trailer was potentially out of gauge.
• Linfox did not have a process for internal, non-standard freight movements at the Stuart terminal to be reviewed and approved for conformance to the permissible loading profile for transport via rail.
• Judging the load’s height without a reference, the heavy lift operator did not detect the over-height load when loading the wagon or later when conducting a walking inspection of the consist from ground level. This allowed the over-height wagon to enter the rail corridor.
• At the Stuart terminal, Aurizon did not routinely apply a process to verify that the dimensions of non-standard loads were within the permissible loading profile, and it did not have measuring equipment available to identify freight loads that were outside the permissible loading profile for transport via rail. (Safety issue)

Safety issues and actions

Absence of measuring equipment

Safety issue number: RO-2021-010-SI-01

Safety issue description: Aurizon did not have measuring equipment available at its Stuart Yard to identify freight loads that were outside the permissible loading profile for transport via rail.

Safety action not associated with an identified safety issue

Additional safety action by Linfox

Linfox advised that it would train forklift and operations staff in Aurizon loading and securing and produce a quick reference guide for loaders.

Linfox also advised:

An awareness campaign has been completed so that all non-standard items are to be referred to and approved by the QLD Capacity and Rail Network Manager. This is regardless of its nature as customer freight or internal shipments.

Linfox are also considering the feasibility of making alterations to the WAVE software system (which has replaced the previous A2B system) to provide a systematic prompt for dimensions when non-standard containers types (flat racks or open top container) are lodged.

Glossary

ATT                  Authority to travel

CCTV               Closed-circuit television

Out of gauge     Exceeding the limits of the approved kinematic envelope, or outline, of the rail corridor to remain clear of obstructions

QR                   Queensland Rail

RIM                  Rail infrastructure manager

Sources and submissions

Sources of information

The sources of information during the investigation included:

• Aurizon
• Linfox
• Queensland Rail
• Rockhampton Regional Council
• the heavy lift operator, capacity officer and freight supervisor.

References

Wickens CD, Hollands JG, Banbury S and Parasuraman R (2013) Engineering psychology and human performance, 4th edition, Pearson Boston, MA.

Wickens CD & McCarley JS (2008) Applied attention theory, CRC Press, Boca Raton, FL.

Submissions

Under section 26 of the Transport Safety Investigation Act 2003, the ATSB may provide a draft report, on a confidential basis, to any person whom the ATSB considers appropriate. That section allows a person receiving a draft report to make submissions to the ATSB about the draft report.

A draft of this report was provided to the following directly involved parties:

• Aurizon
• Linfox
• the Office of the National Rail Safety Regulator (ONRSR)
• Queensland Rail
• the heavy lift operator, capacity officer and freight supervisor.

Submissions were received from Aurizon, Queensland Rail and ONRSR and additional information was received from Linfox. The submissions were reviewed and, where considered appropriate, the text of the report was amended accordingly.

Purpose of safety investigations The objective of a safety investigation is to enhance transport safety. This is done through: identifying safety issues and facilitating safety action to address those issues providing information about occurrences and their associated safety factors to facilitate learning within the transport industry. It is not a function of the ATSB to apportion blame or provide a means for determining liability. At the same time, an investigation report must include factual material of sufficient weight to support the analysis and findings. At all times the ATSB endeavours to balance the use of material that could imply adverse comment with the need to properly explain what happened, and why, in a fair and unbiased manner. The ATSB does not investigate for the purpose of taking administrative, regulatory or criminal action. Terminology An explanation of terminology used in ATSB investigation reports is available here. This includes terms such as occurrence, contributing factor, other factor that increased risk, and safety issue. Publishing information Released in accordance with section 25 of the Transport Safety Investigation Act 2003 Published by: Australian Transport Safety Bureau © Commonwealth of Australia 2022 Ownership of intellectual property rights in this publication Unless otherwise noted, copyright (and any other intellectual property rights, if any) in this report publication is owned by the Commonwealth of Australia. Creative Commons licence With the exception of the Coat of Arms, ATSB logo, and photos and graphics in which a third party holds copyright, this publication is licensed under a Creative Commons Attribution 3.0 Australia licence. Creative Commons Attribution 3.0 Australia Licence is a standard form licence agreement that allows you to copy, distribute, transmit and adapt this publication provided that you attribute the work. The ATSB’s preference is that you attribute this publication (and any material sourced from it) using the following wording: Source: Australian Transport Safety Bureau Copyright in material obtained from other agencies, private individuals or organisations, belongs to those agencies, individuals or organisations. Where you wish to use their material, you will need to contact them directly.

[1]     Flat racks are a type of shipping platform designed for oversized loads that do not fit inside a standard shipping container.

[2]     Out of gauge: exceeding the limits of the approved kinematic envelope, or outline, of the rail corridor to remain clear of obstructions.

[3]     Roll-by inspection: an inspection conducted by a qualified worker to identify issues with the rail consist, normally for wheel lockups or dragging equipment. It was conducted while standing at ground level adjacent to the train as it slowly ‘rolls’ past the worker under locomotive power.

[4]     The loading outline is a 2-dimensional cross-section of the maximum permissible envelope or shape of a rail vehicle at rest.

[5]     The height of a standard 20-foot shipping container is about 2.6 m.

[6]     ATSB investigation RO-2020-009, Wagon out of gauge on freight train 2BW4, Main North rail line, New South Wales, on 16 June 2020.

[7]     ATSB investigation RO-2018-011, Dewirement involving freight train YC77, Cooroy, Queensland, on 18 August 2018.

[8]     ATSB investigation RO-2018-003, Loading irregularity on train 2BM9, Maitland, NSW on 16 January 2018.

[9]     For example, ATSB Occurrence Investigation AO-2009-072 (reopened), Fuel planning event, weather-related event and ditching involving Israel Aircraft Industries Westwind 1124A, VH-NGA, 6.4 km WSW of Norfolk Island Airport, 18 November 2009.

Safety summary

What happened

On the afternoon of 18 August 2021, an Airbus Helicopters Deutschland BO105 CBS‑5 helicopter registered VH-NVH and operated by Surf Life Saving Queensland, departed Archerfield Aerodrome, Queensland to conduct aerial work operations. There were 3 crew on board.

During initial climb, the pilot noticed the onset of abnormal airframe vibration, which became more severe as airspeed increased. The pilot returned the helicopter to Archerfield, where it was landed without incident. The pilot subsequently identified a crack in one of the main rotor blades.

What the ATSB found

The main rotor blade crack was consistent with the in-flight vibration experienced. The crack originated at the location of a previous blade repair, and minor damage was also present in the same location on the other 3 rotor blades. There were no manufacturing or operational factors identified for the blade damage.

Safety message

This occurrence is a reminder for pilots to be vigilant for changes in aircraft noise and vibration. While the threshold for acknowledgement of changes can be subjective, based on an individual’s familiarity and experience, mild deviations from normal flight conditions could still be an indication of a developing technical issue.

Executive summary

Why the ATSB conducted this study

Between 1 July 2014 and 31 August 2022, 24 rail or road users were fatally or seriously injured in collisions between trains and heavy vehicles at Australian level crossings. The ATSB conducted this safety study to improve understanding of the risks associated with level crossing collisions involving heavy vehicles. The goals of this study were to:

• Compare the severity of level crossing collisions involving heavy vehicles to collisions involving light road vehicles.
• Provide a statistical description of level crossing collisions involving heavy vehicles.
• Identify common contributing factors associated with level crossing collisions involving heavy vehicles.
• Identify systemic safety issues associated with the safety system for level crossings, including the design of level crossings used by heavy vehicles.

To accomplish these goals, the ATSB used quantitative and qualitative methods to analyse data collected by rail regulators in Australia and the United States. The ATSB also reviewed all reported level crossing collisions involving heavy vehicles in Australia from July 2014 to August 2022 (49 collisions), and collected records from rollingstock operators, rail infrastructure managers, police, and other organisations for each of these accidents.

What the ATSB found

The annual number of level crossing collisions between road vehicles and trains remained relatively constant between July 2014 and June 2022.

Data from Australian and United States rail regulators showed that level crossing collisions involving heavy vehicles were more likely to lead to injuries to the occupants of rail vehicles, to damage to rail vehicles and track, and to derailment of rail vehicles. Derailment of rail vehicles was also more likely to occur in level crossing collisions in which the road vehicle struck the train, compared to those where the train struck the vehicle. Comparison of records of the number of total road vehicles registered in Australia, and records to the number of kilometres travelled by different road vehicle types, showed that heavy vehicles had a higher rate of level crossing collisions. As a result, heavy vehicles present a greater risk of level crossing collision as a function of both likelihood (per road vehicle and road kilometres travelled) and consequence compared to light road vehicles.

The majority of level crossing collisions arose from heavy vehicle drivers entering the level crossings following some form of unintentional error or omission. In at least 14 accidents, it was likely the heavy vehicle driver intentionally entered the level crossing in a manner contrary to road rules, however even in these instances the intention was to proceed through the crossing prior to the arrival of a train.

The review of level crossing collisions identified common factors which may have contributed to the actions of heavy vehicle drivers. These included:

• In at least 12 collisions the heavy vehicle driver had regularly used the level crossing prior to the collision with the train. The drivers' previous experience at the level crossings may have led to a low expectancy for trains and contributed to them not detecting a requirement to stop and give way.
• In at least 14 collisions, the heavy vehicle driver’s view of the track or level crossing protection equipment was obstructed by vegetation, the design of the heavy vehicle cab, poor crossing lighting, or sun glare.
• Consistent with prior research showing that train horns have limited effectiveness for alerting road vehicle drivers approaching level crossings, in at least 25 accidents the horn was not effective at alerting the heavy vehicle driver to the presence of the train.

These observations were based on a partial set of the 49 collisions involving heavy vehicles, since in many instances information about the actions of heavy vehicle drivers and the factors which influenced these actions was not available from operator or police reports. The review identified that such information is typically only available when an independent no-blame transport safety investigation is conducted.

The collisions reviewed in this study mostly occurred at level crossings designed according to the required standards. However, this study identified one systemic safety issue with level crossing design standards. Of 6 collisions where the heavy vehicle driver did not identify the presence of activated flashing lights, 5 occurred on crossings with curved road approaches, all of which were right curves. Following a review of the applicable standards for designing and assessing level crossings (AS1742.7:2016 Manual of uniform traffic control devices, Part 7: Railway crossings), and research literature concerning visual attention in curved driving, the ATSB determined that methods used to calculate safe stopping distances (and determine the need and location of active advanced warning signs) for road approaches to level crossings did not account for the likelihood of detecting the level crossing ahead based on the normal visual focal points of road drivers negotiating a curved road.

The collisions primarily resulted from level crossing warnings or the presence of trains not being detected, being detected late, or being perceived incorrectly. Many of the errors and omissions which lead to level crossing accidents reflect the inherent variability of human performance.

The review identified that passively controlled level crossings, in particular, rely on the road vehicle driver visually detecting the presence of a train and identifying a requirement to stop and give way, they are susceptible to situations where drivers do not look for, or detect the presence of, a train, and there are limited effective recovery controls to prevent a collision when this occurs. The use of redundant controls, and particularly fail-safe engineering controls, improve the safety at passively controlled level crossings. The study considered one such form of control (in-vehicle alerting systems for level crossings), however there are significant barriers to the implementation of such systems.

What has been done as a result

Standards Australia reported they will review the standard AS1742.7 and determine if additional information or guidance may be provided to manage risks associated with curved road approaches to level crossings.

Safety message

This study highlights the increased risk posed by level crossing collisions with heavy road vehicles. Interventions which target these vehicles are likely to provide significant leverage in improving the overall safety at level crossings.

The accidents reviewed in this study demonstrate the potential for driver errors at level crossing to cause significant harm. As also demonstrated in this study, the performance of road vehicle drivers is inherently susceptible to unintentional errors. While the level crossing safety systems rely on road vehicle drivers always detecting a level crossing (and at passive crossings, the presence of trains) it is certain that this will fail from time to time and result in accidents in the future. The possibility of the future use of engineering controls which alert road users to a requirement to stop will almost certainly provide an enhanced level of safety at level crossings, by reducing the reliance on road vehicle drivers to attend to and detect the presence of trains.

Background

The Australian rail network comprised about 46,000 km of track and had an annual throughput of approximately 250 million km of combined passenger and freight journeys in 2021.[1] Across this network, records from the Office of the National Rail Safety Regulator (ONRSR) indicated there were almost 11,000 operational[2] level crossings where there is an interface between rail traffic and road vehicles.[3] At these interfaces there is a risk of collision, which is managed using different forms of traffic control equipment and associated procedures.

Relative to the volume of traffic conveyed across the rail network, collisions between trains and road vehicles at level crossings are rare. Rail safety data produced by ONRSR showed that for every million km travelled by freight trains between 2016 and 2021, there was an average of about 0.18 collisions with road vehicles at level crossings. The rate for passenger trains was about 0.10 per million km.

Though rare, level crossing collisions can have severe consequences. Collisions between passenger cars, motorcycles or bicycles often result in tragic consequences for road users. Where a heavy vehicle is involved in a level crossing collision, the rail system risks associated with the collision are much greater, including the increased potential for multiple fatalities onboard the train. In recent decades, several collisions between heavy vehicles and trains have resulted in multiple fatalities of train occupants:

• On 27 November 2008, 2 train drivers were fatally injured when a B-double combination truck collided with a passenger train in Rungoo, Queensland.[4]
• On 5 June 2007, 11 train passengers were fatally injured when a semi-trailer hit a train at a level crossing in Kerang, Victoria.[5]
• On 13 October 2002, 3 people in the cabin of a steam train were fatally injured when it collided with a B-double combination truck at a level crossing in Benalla, Victoria.[6]

To understand the trends and characteristics of level crossing collisions involving heavy vehicles requires sufficient information to enable detailed analysis. The ATSB, as the national independent investigator of rail safety occurrences, investigated about 20% of these occurrences between July 2014 and July 2022.

Safety study goals

This safety study aimed to improve understanding of the risks of level crossing collisions involving heavy vehicles. The goals of this study were to:

• Compare the severity of level crossing collisions involving heavy vehicles to level crossing collisions involving other road vehicles.
• Provide a statistical description of level crossing collisions involving heavy vehicles.
• Describe common themes associated with level crossing collisions involving heavy vehicles.
• Identify systemic issues associated with the safety system for level crossings, including the design of level crossings used by heavy vehicles.

Level crossing safety systems: an overview

Level crossings are the physical interface between road and rail traffic. Both modes of transport are operated as entirely separate entities and have different rules, procedures, characteristics and operational limitations. Trains are typically significantly larger than road vehicles, and when a road vehicle enters a level crossing in the path of a train, the only action that a train driver can take is to try to alert the road vehicle driver with the train horn and apply train braking. The train may not slow significantly, if at all, before the collision occurs.

Given the limitations on braking and accelerating trains, by necessity, road vehicle drivers must give way to trains at level crossings. Road traffic law codifies the right of way of rail traffic, with the Australian road rules (model law) stating:

Level crossing traffic control systems use various signs, lights and other devices (level crossing protection equipment) to firstly alert an approaching road vehicle driver to the presence of the level crossing, and secondly instruct the road vehicle driver to take appropriate action to give way to trains.

Passive control level crossings control the movement of road traffic using signs and devices (including Give Way or Stop signs). Passive level crossing equipment is functionally static, meaning that there is no change to the equipment when a train is approaching compared to when no train is approaching. As such, passive control level crossings rely on road vehicle drivers (and pedestrians) detecting both the sign itself and then the approach or presence of a train by direct observation.

Active control level crossings control the movement of road traffic using devices such as flashing light signals, gates or barriers, or a combination of these. Active level crossing devices are activated prior to, and during, the passage of a train through the crossing. If the crossing devices are activated (level crossing lights are flashing and/or boom gates are down), then road vehicle drivers' attention should be drawn to their active status, and road rules require the road vehicle driver to stop and wait until the crossing devices are no longer active, removing the need for the road vehicle driver to detect the presence of a train.

Methods and sources

Overview

To analyse trends and characteristics (including accident severity) of level crossing accidents in Australia, this study used records of level crossing collisions and near misses in the national rail safety data collected by the Office of the National Rail Safety Regulator (ONRSR).

The study also used data from the United States Federal Railroad Administration (FRA) to support analyses of level crossing accident severity. The road and rail systems in the US are broadly equivalent to those in Australia.[7] Both jurisdictions (Australia and the United States) use similar forms of level crossing protection mechanisms, and the fundamentals of level crossing collisions are unlikely to be significantly different; level crossing collisions involve relatively small road vehicles colliding with comparatively larger trains. The ATSB considered that level crossing accident data from the United States provided valid data for the purpose of the analyses.

Australian level crossing collision data

Office of National Rail Safety Regulator national rail safety database

The Rail Safety National Law Act 2012 required railway operators report all notifiable occurrences to ONRSR or another authority specified by ONRSR. The Rail Safety National Law Regulations 2012 specified that collisions between trains and vehicles at level crossings were Category A occurrences, whereas near misses at level crossings were Category B occurrences.[8] The Rail Safety National Law does not require road vehicle operators to report level crossing accident information to ONRSR.    

The national rail safety database recorded information provided to ONRSR under the reporting requirements specified in the Rail Safety National Law. This database commenced with the establishment of ONRSR on 20 January 2013, however coverage of different Australian jurisdictions (States) occurred gradually. ONRSR advised the dataset for level crossing occurrences was reliable from 1 July 2014 onwards. The ATSB analysis used occurrences from the national rail safety database between 1 July 2014 and 30 June 2022.

The national occurrence database recorded:

• a narrative description of the collision or near miss, which typically recorded the initial wording of the notification provided by the operator and sometimes included follow-up information
• the date, time and location of the level crossing collision or near miss
• the operator and rail infrastructure manager involved
• the primary level crossing protection equipment (flashing light, boom gate, stop sign or give way sign) at the level crossing
• the type of rollingstock and road vehicle involved in the collision or near miss
• fatalities and injuries sustained by rail passengers, rail operating crew and road vehicle occupants.

For the time period analysed, the national rail safety database did not record:

• the level of damage sustained by road vehicles, and rail and road infrastructure
• the speed, direction, mass and length of rail or road vehicles
• the actions of the road user.

The national rail safety database recorded 283 level crossing collisions with vehicles between 1 July 2014 and 30 June 2022. Of these, 220 were collisions with light passenger vehicles, with 44 collisions involving heavy freight vehicles.[9] The remaining 20 collisions involved buses (4), special purpose machinery (5), bicycles (5), motorcycles (1), a dangerous good vehicle (1) and other vehicles (4). To analyse the severity and characteristics of occurrences involving heavy vehicles, the ATSB identified the level crossing collisions involving heavy vehicles recorded in the ONRSR national rail safety database for additional evidence collection.

A set of 47 collisions was identified in the national rail safety database, which comprised:

• 42 collisions with vehicles recorded as heavy freight vehicles[10]
• 3 collisions with buses[11]
• one collision each with vehicles coded special purpose machinery,[12] and dangerous goods vehicles.

Of the remaining collisions in the national rail safety database, the ATSB identified a subset of 216 level crossing collisions involving light road vehicles for comparative analyses. Light vehicles were defined as passenger cars and motorcycles, but not bicycles or farm or roadwork equipment. The comparative analysis also excluded collisions with hi-rail/road-rail vehicles.[13]

In July 2022, ONRSR introduced new requirements for operators submitting notifiable occurrence reports. Under the new requirements, rail operators reporting level crossing collisions and near misses were required to report the damage sustained by rail vehicles and infrastructure, whether a derailment occurred, and the cause of the collision.

Additional information collection

Between July and August 2022, the ATSB commenced 2 investigations into level crossing collisions involving heavy vehicles, these collisions were added to the 47 heavy vehicle level crossing collisions identified from the national rail safety database.

For each of the 49 in-scope collisions, the ATSB sought information from rail operators, rail infrastructure managers, police, state road authorities and other parties. These records included investigation reports and level crossing assessments. Follow-up enquires were made to enhance the dataset. However, in many instances important information was not recorded in investigation reports and was not available for follow-up enquiry due to the passage of time from the events. As such, some of the information presented in subsequent sections is drawn from a partial sample of the identified level crossing collisions.

Level crossing accident data collected in United States

To support analysis of level crossing collision severity, the ATSB obtained records from the United States Federal Railroad Administration (FRA). Due to greater rail and road traffic volumes, there were about 60 times more recorded level crossing collisions in the United States than Australia, and the FRA datasets provided additional statistical power for the ATSB analyses. Regulations in the United States required that collisions between railway equipment and vehicles at level crossings (referred to as ‘grade crossings’ in the United States) were reported to the FRA. The regulations required that reports of level crossing collisions included the:

• type of road user involved
• speed, direction and position of the road user
• environmental temperature, light and weather conditions
• train type, consist length and speed
• level crossing equipment
• actions of the road user.

In addition, for accidents exceeding a threshold damage value (about A$16,000 in 2022), operators were required to report the:

• mass of the train consist
• cost of rail equipment and track damage
• number of derailed train cars.

These data were contained in two databases. The Highway-Rail Grade Crossing Accident (HRA) database contained data for all level crossing accidents, and the Rail Equipment Accident/Incident (REA) database contained data on accidents exceeding the damage cost threshold.

ATSB analysed data from both datasets from 2012 to 2021. After data cleaning and removal of irrelevant collisions, there were 19,495 collisions in the HRA dataset, and 2,283 records of highway rail collisions (level crossing collision) in the REA dataset. There were about 700 duplicate records in the REA dataset. The ATSB identified a final sample of 1,901 unique HRA records with matching REA records.

Descriptive statistics

Australian level crossing statistics

ONRSR provided the number of road crossings, based on information reported by rail operators. ONRSR stated that while the number of road crossings had been validated by reasonability checks, it was not possible to determine the accuracy of the data reported by operators.

The ONRSR database showed that in December 2023, there were almost 11,000 operational level crossings which managed traffic between trains and road traffic. This included almost 3,000 active control crossings, and almost 7,000 passive control crossings (there were about 1,500 operational crossings which were recorded as unprotected). ONRSR advised it was not possible to disaggregate their data on the basis of whether level crossings were on public or private roads. Table 1 shows the distribution of operational level crossings by protection type in each Australian state and territory.

Table 1: Counts of road level crossings, by primary protection type and jurisdiction

Source: ONRSR

During the development of the safety study, the ATSB received submissions from stakeholders in some jurisdictions which identified that the number of level crossings presented in Table 1 were not consistent with other records, including those stored in the Australian Level Crossing Assessment Method dataset. ONRSR also identified that there were known differences between the number of crossings identified in the ONRSR database and the ALCAM dataset, and  the data had not been cross-validated between the datasets.

Australian level crossing collisions

Characteristics of all level crossing collisions and near misses

There were 283 collisions and 4,319 near misses between trains and road vehicles recorded in the Australian national rail safety database. These totals included collisions involving hi-rail vehicles, bicycles, and farm and roadwork equipment.

Key statistics involving the type of train included:

• There were 120 collisions and 1,801 near misses involving freight trains.
• 122 collisions and 1,895 near misses involved regular passenger services.

Key statistics involving the type of crossing included:

• 160 collisions and 3,133 near misses occurred at active control crossings.
• 115 collisions and 1,086 near misses occurred at passive control crossings.

Other descriptive statistics for collisions and near misses are described in Appendix A.

Characteristics of level crossing collisions involving heavy vehicles

Environmental conditions

Of the 49 collisions reviewed in the safety study, 3 occurred in dark conditions (after astronomical twilight).[14] There were a further 7 collisions when the sun’s elevation was between -18° and 6°, meaning the sun was low in the sky and twilight conditions were apparent.

Information about the road conditions was recorded for 40 of the collisions. In 37 collisions the road was reported to be dry, and in 3 collisions the road was reported to be wet. Thirty-three of the 49 collisions occurred in rural locations, and 16 collisions occurred in built-up or urban areas.

Train characteristics

More than two-thirds of level crossing collisions with heavy vehicles involved freight rail operations (Table 2).

Table 2: Operation category of trains involved in level crossing collisions with heavy vehicles

The maximum reported train mass was 10,109 tonnes, with 18 collisions involving trains with a reported mass of over 1,000 tonnes. The maximum train length was 2,964 m, with 6 collisions involving trains 1,000 m or longer. Thirteen collisions involved driver only operations. Where the number of passengers was recorded, the maximum was 250 (Table 3).

Table 3: Maximum and average train mass, length and passenger numbers

Information about the time and distance of emergency braking prior to collision was available for 36 collisions (Table 4). In 13 instances, the train crew either did not brake, or braked at about the point of impact (2 seconds or less prior to impact). These included instances where the train crew saw the road vehicle slowing or stopped for the crossing, and therefore did not anticipate that a collision would occur. These instances also included situations where the train crew’s vision of the level crossing was blocked by curved track and vegetation, preventing the train crew from identifying the potential collision earlier.

In 4 instances, train crew made emergency brake applications for 10 or more seconds prior to the collision, including up to 213 m braking distance prior to the collision. Three of these collisions involved instances were at level crossings controlled by boom gates, and involved heavy vehicles stopped on the crossing. The other instance involved a very large freight train (5,330 tonnes) which was unable to stop after a truck driver stopped then proceeded from a Stop sign. Due to the train braking over a long distance, the collision speed in these occurrences was significantly reduced, probably leading to reduced consequences (injuries and damage) to the train and road vehicle occupants than if braking had been applied at a shorter distance to the collision point.

The average reported speed of the trains prior to braking for the collision was 62 km/h, with a maximum of 160 km/h reported. The average reported collision speed was about 51 km/h, with a maximum reported speed of 110 km/h.

Table 4: Train speed and braking prior to level crossing collisions

Heavy vehicle information

Over half (28) of the heavy vehicles involved in level crossing collision were articulated vehicles (semi-trailers or trucks with trailers). Seventeen vehicles were unarticulated vehicles (garbage trucks, flat-bed and box trucks) and 3 were buses. In terms of the classes of heavy vehicles described by the National Heavy Vehicle Regulator,[15] there were 27 General Access Vehicles, 14 Restricted Access Vehicles, and there was insufficient information to classify 8 vehicles.

The maximum recorded gross mass was 148 tonnes, and 6 vehicles had a recorded mass of 70 tonnes or greater. The greatest number of occupants recorded was 20 (a passenger bus), with the next highest being 3. Thirty-seven collisions involved single-occupant vehicles, and 3 collisions involved circumstances where the occupants had vacated the vehicle prior to the collision.

Table 5: Mass, length and occupant numbers for heavy vehicles involved in level crossing collisions

Reported mechanical problems were associated with 4 of the collisions identified in this study. In 2 instances, post-accident assessments identified problems with truck braking systems which may have contributed to the trucks failing to stop ahead of the crossing. In 2 other collisions, the heavy vehicles stalled on the level crossing and were unable to clear the crossing prior to the train arriving.

Police records indicated that one heavy vehicle driver was affected by alcohol or other drugs, and was reported to be fatigued/drowsy prior to the collision.

Level crossing characteristics

There was a relatively even distribution of collisions involving heavy vehicles at passive control crossings and collisions at active control crossings. Considering that heavy vehicles accounted for about 18% of level crossing collisions recorded in the national rail safety occurrence database, heavy vehicles were significantly under-represented for collisions occurring at Boom gates, and over-represented for collisions at Give way signs (Table 6).

Table 6: Level crossing collisions by protection equipment type

Most occurrences (39) occurred on sealed roads, with 10 collisions occurring on unsealed roads. The average road speed limit, where recorded, was 77.1 km/h, and 15 collisions occurred on roads where the speed limit was 100 km/h or greater. Where recorded, the average track speed at the level crossing locations of the occurrences was 82.6 km/h, with a maximum track speed of 160 km/h.

Problems with level crossing design and maintenance

There are several standards applicable to the design and maintenance of level crossings in Australia. These include:

• Australian Standard AS 7658:2020 Level Crossings: Rail Industry Requirements. This standard was developed and maintained by the Rail Industry Safety and Standards Board (RISSB). It describes minimum operational and engineering requirements of the life cycle of a level crossing.
• Australian Standard AS 1742.7(2016), Manual of uniform traffic control devices. Part 7: Railway crossings. This standard was developed by the Australian Standard Committee MS‑012. It described design guidance for the installation of level crossing protection equipment, including methods for assessing the sighting distances required at different level crossings. Additional discussion of AS 1742.7 is provided in Standards and other guidance relevant to placement of crossings on curved road approaches, and the formula used to calculate sighting distances for level crossings are described in Appendix B.

Key aspects of these standards include that:

• AS 7658 required that rail infrastructure managers establish and maintain procedures for the rail portion of the level crossing, and that an interface agreement exists with the road manager to ensure that ‘all facets of the monitoring and maintenance of the level crossings is undertaken’. This includes procedures for inspection and testing and vegetation management. The standard further required that ‘removal of plant growth shall be required to ensure retention of sighting distance’.
• AS 7658 stated that whistle boards may be installed on the approach to level crossings.
• AS 7658 stated that that ‘Adequacy of street lighting at a level crossing shall be assessed against the requirements in AS/NZS 1158 [Road lighting] during a level crossing risk assessment. Street lighting provided for level crossings shall comply with AS/NZS 1158 and impacts on train drivers, road users and pedestrians shall be evaluated, and outcomes documented.’
• AS1742.7 stated that level crossings should be located so that there is sufficient distance between the crossing and a downstream intersection to accommodate the road design vehicle[16] and a safety factor of 5 m. The intent of these provisions is to prevent so-called ‘short stacking’, where a long vehicle stops across a crossing while queueing for another intersection.

The safety study considered evidence of problems with the design or maintenance of the level crossing locations of the 49 collisions reviewed in this study. Analysis of the design of AS1742.7 is described in Analysis of level crossing safety systems. Two ATSB investigations, 4 rail infrastructure manager reports and one State government investigation identified problems with the design or maintenance the level crossing:

• ATSB investigation RO-2014-024 identified that a stand of trees had self-sown within the rail reserve. When a truck approached the level crossing, the driver’s view was partially obscured by this vegetation. The investigation noted that previous inspections had recorded the presence of the trees, but this had not led to the removal of the trees.
• ATSB investigation RO-2016-009 identified that the Stop sign level crossing required road vehicle drivers sight approaching rail traffic at an obtuse angle (greater than 90° but less than 180°). When a semi-trailer truck stopped at the crossing, the driver’s view of an approaching train was restricted and they did not identify the risk of collision.
• A rail infrastructure manager report noted that a Stop sign level crossing was located in a dark industrial area. There was poor lighting on the crossing itself and contrasting high levels of lighting in the background and foreground. In these dark conditions, a truck driver approaching the Stop sign level crossing did not detect that a rail safety worker was controlling the crossing or that a freight train was indexing in reverse over the crossing.
• A rail infrastructure manager and operator report noted that a temporary Stop sign level crossing had been installed without other approach signage, and with no whistle board installed for approaching trains. A train driver approaching the crossing did not sound the train horn until they identified a truck, which had stopped at the level crossing. The truck driver did not hear the horn and proceeded into the path of the train.
• A state government investigation report identified that a level crossing protected by flashing light signals was designed with a stop line placed too close to the lights assembly. When a bus stopped at the crossing while waiting for traffic to clear, the driver’s view of the near-side lights was obstructed. When traffic cleared, the bus driver, who had an unobscured view of the far-side flashing lights, proceeded into the crossing against the flashing lights.
• A rail infrastructure manager report identified that the road configuration near a Stop sign level crossing was not appropriate for some heavy vehicle classes as there was insufficient room to clear the crossing when queued at an intersection beyond the crossing. There was no signage or pavement markings to discourage road users from queuing across the crossing. A heavy vehicle driver approaching the crossing did not stop at the Stop sign (causing the train drivers to apply emergency brakes), then was unable to clear the crossing before the train arrived.
• A rail infrastructure manager and operator report identified that a level crossing flashing light assembly did not face towards a side road approaching the crossing. A heavy vehicle driver approaching from the side road did not detect the requirement to stop at the level crossing.  

In total, there were at least 7 collisions between heavy vehicles and trains where problems with the design or maintenance of the level crossings were probably contributory to the collisions. Reports from a further 2 collisions identified that the sighting provided to road users was insufficient considering the requirements of Australian Standards AS1742.7. In these instances, the sighting deficiencies were for rail or road approaches other than those involved in the collisions, so were not contributory to the collision. Reports for 8 other occurrences identified various other minor problems, including faded signs and minor discrepancies between the signage provided and the requirements of AS1742.7.

In summary, the evidence available to this review did not indicate significant problems with the design or maintenance of most level crossings where collisions between heavy vehicles and trains occurred, in terms of compliance with applicable design standards. The absence of such evidence, however, is not necessarily evidence that no problems with the design and maintenance of crossings existed. As described further in Study limitations, this review did not involve site inspections of level crossings (other than those previously investigated by the ATSB), and the ATSB did not seek to otherwise audit the compliance of the level crossings with relevant standards.

Level crossing collisions in the United States

Collisions and fatalities by vehicle types

The number of level crossing collisions and fatalities recorded in the US Federal Railroad Administration (FRA) Highway-Rail Grade Crossing Accident (HRA) dataset is summarised by vehicle type (Table 7). The vehicle type variable was then categorised as Heavy (bus, truck or truck-trailer) and Light (all other vehicles), with the number of collisions and collision fatalities for each category shown in Table 8.

Table 7: Level crossing collision statistics by road vehicle type, FRA (HRA) data, June 2012 to June 2021

[1] This category describes passenger vehicles such as sedans, but does not include motorcycles

Table 8: Level crossing collision statistics for 'Heavy' and 'Light’ vehicles (excluding pedestrian collisions)

Types of trains involved

Concerning all road vehicles, 74% of level crossing collisions involved freight trains. Collisions involving heavy vehicles accounted for about 25% of all collisions with freight trains, and about 16% of collisions with passenger trains.

Table 9: Level crossing collisions by train type and vehicle type, FRA HRA data

Level crossing protection equipment

More than half (56%) of level crossing collisions were recorded at active control level crossings. Heavy vehicles were involved in about 25% of all level crossing collisions (active and passive controlled crossing combined). They were over-represented in collisions at passive control crossings, and under-represented for collisions at active control crossings (Table 10).

Table 10: Level crossing collisions by crossing level crossing protection equipment type and vehicle type

Note: ‘Proportion heavy’ describes the proportion of accidents at each level crossing type which involved heavy vehicles. For example, 37% of accidents at Stop sign crossings involved heavy vehicles.

Road vehicle driver actions associated with level crossing collisions

The most common road vehicle driver action associated with level crossing collisions was a failure to stop prior to a level crossing, accounting for 40% of collisions (Table 11). Heavy vehicles were proportionately more likely to be involved in collisions where:

• The road user did not stop at the level crossing (1.3 times more likely).
• The road user stopped at the crossing then proceeded into the path of an oncoming train (1.6 times more likely).

Table 11: Level crossing collisions by road vehicle driver actions and vehicle type

The road user action attributed to level crossing collisions varied significantly as a function of the type of level crossing protection equipment in use. Table 12 describes the proportion of collisions attributable to different motorist actions, by crossing and vehicle type.

Table 12: Motor vehicle actions by crossing and road vehicle type

Note: Percentages shown in this table describe the proportion of accidents for each crossing type associated with each action type. For example, 22% of Heavy vehicle collisions at Stop sign controlled crossings involved the motor vehicle driver stopping on the crossing.

Vehicle speed

Most collisions recorded in the FRA HRA dataset involved trains colliding at speed with stopped or slow-moving road vehicles. The mean recorded train speed was 47 km/h, with a maximum reported speed of 177 km/h. The mean estimated collision speed for road vehicles was about 11 km/h for heavy vehicles and about 14 km/h for other road vehicles.

Comparison of Australian and United States Level Crossing collision data

There were consistent characteristics in the level crossing collision data for Australia and the United States. There was a similar proportion of level collisions involving heavy vehicles, with 18% of collisions in Australia involving heavy vehicles, compared to 25% in the United States. Similarly, data for both countries showed that heavy vehicles were under-represented in accidents occurring at crossings protected by boom gates, and over-represented in accidents occurring at passively controlled crossings.

The FRA data showed that the most common road user action associated with level crossing collisions was a failure to stop. As described in Errors and violations associated with level crossing collisions, this action was also the most common road user action identified in the 49 collisions involving heavy vehicles in Australia.

Analysis of heavy vehicle collision severity and frequency

Severity of level crossing collisions involving heavy vehicles

Previous research and reviews

In 2008, the ATSB published a

Analyses of US level crossing collision datasets have previously shown that when heavy vehicles were involved in a collision, there was a much greater likelihood of a derailment occurring (Chadwick, Saat and Barkan, 2012).[17] Other research noted that the damage costs of level crossing collisions involving commercial vehicles (which includes heavy vehicles) are 3-4 times greater than collisions involving other road vehicles (Hellman and Poirier, 2019). 

Injuries and fatalities to rail passengers and crew

Australia

The ATSB’s analysis of the national rail safety database identified 47 injuries to rail passengers and crew in 285 level crossing collisions with road vehicles,[18] 7 of these injuries were classified by the ATSB as serious as they resulted in hospital admission. The majority of injuries to rail occupants (7 serious and 34 minor) resulted from 49 reported collisions involving heavy vehicles, this included 18 passengers and a conductor who sustained injuries after a collision between a passenger train and a truck on 15 July 2016 at Phalps Road, Victoria.

There were no fatalities of railway employees or passengers resulting from a level crossing collision in the period July 2014 to August 2022.

United States

In the collisions recorded in the FRA HRA dataset, there was an average of 25 rail injuries (injuries to rail passengers or staff) per 100 collisions involving a heavy vehicle, compared to 3.5 per 100 collisions involving light vehicles. A Mann-Witney U test[19] found that the difference in average rail injuries by vehicle type was statistically significant (p<.005).

Fatalities to rail occupants were extremely rare, with 7 collisions (out of 19,495) resulting in 11 rail fatalities. There were 5 separate collisions involving heavy vehicles which each caused one rail fatality, whereas one collision involving a light vehicle resulted in 5 fatalities[20] (another collision with a light vehicle resulted in one fatality). Table 13 shows the total number of fatalities and injuries of rail and road users recorded in the FRA datasets.

Table 13: Fatalities and injuries by road user type in US level crossing collisions, 2011 to 2021

Fatalities and injuries to road users

Australia

There were 23 road fatalities from 283 level crossing collisions recorded in the national rail safety database, with 5 fatalities resulting from collisions involving heavy vehicles and 17 resulting from collisions with non-heavy vehicles (one fatality involved a collision with a cyclist). The average number of road fatalities per collisions involving heavy vehicles (0.11 fatalities per collision) was greater than collisions involving non-heavy vehicles (0.08 fatalities per collision), however the difference was small.

The ATSB review of 49 heavy vehicle collisions identified that road vehicle drivers and passengers sustained 33 injuries from level crossing collisions with heavy vehicles (0.67 injuries per collision), including 12 serious injuries. This included 17 injuries (6 serious) sustained by the occupants of a passenger bus which was struck by a train at Draper Street in Brisbane in 2015.[21] The national rail safety database showed that there were 60 injuries to road users in the 216 collisions involving light vehicles (0.28 injuries per collision).

United States

Analysis of the FRA HRA dataset (19,495 collisions) showed there were 1,770 total road fatalities. A Mann-Witney test showed that the average number of road fatalities per collision was statistically significantly lower for collisions involving heavy vehicles (0.05 fatalities per collision), compared to collisions involving light vehicles (0.11 fatalities per collision;  p<.001).

Similarly, there were fewer injuries to road users for collisions involving heavy vehicles (0.23 per collision), compared to collisions involving light vehicles (0.36 per collision; p<.001).

Rail damage

Australia

The national rail safety database did not record estimated damage for level crossing collisions. As such it was not possible to compare the damage sustained in Australian level crossing collisions involving heavy vehicles, compared to collisions involving light vehicles. For the 49 collisions reviewed in this study, there was typically insufficient information to quantify the damage sustained by rail vehicles, road vehicles or infrastructure in most collisions.

The ATSB reviewed the damage reported in various sources, and identified that:

• 11 collisions resulted in the derailment of at least 1 rail car.
• In 16 instances the rail vehicle sustained substantial damage, which required major repairs or significantly affected the performance of the vehicle. In 31 instances rail vehicles sustained only minor damage such as scratches or small dents.
• In 33 instances the road vehicle sustained substantial damage, including several collisions where the vehicle was destroyed. In 13 instances the road vehicle sustained minor damage.
• In 23 collisions there was no reported damage to infrastructure. In 10 instances there was minor infrastructure damage reported, and in 7 instances there was substantial infrastructure, such as large sections of destroyed track.

The following examples illustrate the significant rail damage resulting from collisions with heavy vehicles:

• A collision between a truck, trailer and dog combination with a grain train resulted in extensive damage to the locomotive, with total repair costs estimated at $480,000.
• A collision between a prime mover and trailer with a freight train resulted in damage to 20 m of track, 1,250 sleepers and 90 tonnes of ballast, with an estimated repair cost for infrastructure assets of over $300,000.
• A collision between a prime mover and a grain train led to the derailment of the train, resulting in significant damage to two locomotives and multiple wagons.

United States

The FRA Rail Equipment Accident/Incident (REA) dataset recorded the estimated rail equipment (rollingstock) and track damage for accidents which exceeded the damage threshold (about A$16,000). Of 1,901 level crossing collisions recorded in this dataset, the average equipment damage for collisions involving heavy vehicles was around USD$78,000, compared to USD$31,000 for collisions involving light vehicles. The average track damage for level crossing collisions involving heavy vehicles was USD$31,000, compared to USD$19,000 for collisions involving light vehicles. Mann-Witney tests showed both of these differences were statistically significant (p<.001).

Derailment

Australia

A mixed-methods approach was used to identify the number of derailments resulting from heavy vehicle and light vehicle level crossing collisions:

• All level crossing collisions (heavy and light road vehicles) in the national rail safety database were cross referenced with those also classified as derailments and/or identified as a derailment in the accident description field.
• For collisions involving heavy vehicles, operator and rail infrastructure manager reports were used to supplement the data from the nation rail safety database. Combined these methods identified that 11 of the 49 collisions resulted in derailment (9 of 47 collisions prior to July 2022).
• For collisions involving light vehicles, there was only one of 216 collisions that resulted in derailment. This was a collision between a passenger train and an abandoned light vehicle.

Fisher’s exact test was conducted to examine the relationship between road vehicle type and derailment for the 283 heavy and light vehicle collisions in the national rail safety database. The relationship was significant (one-tailed p<0.001), showing that collisions involving heavy vehicles were more likely to lead to derailment.

United States

The FRA data showed that there were 141 derailments in 4,886 collisions involving heavy vehicles, compared to 43 derailments in 14,609 collisions involving light vehicles.[22] Fisher’s exact test was showed that the difference in distribution between derailments and vehicle type was also significant in the FRA data (one-tailed p p<.001).

Summary of analysis of accident severity

Consistent with previous research, level crossing accident data from Australia showed that collisions involving heavy vehicles were more likely to result in injury to rail and road vehicle occupants, and more likely to cause derailment of rollingstock. Due to limitations in the available data, it was not possible to compare the accident damage sustained to rollingstock, infrastructure and road vehicles in level crossing collisions involving heavy vehicles and light vehicles, for collisions occurring in Australia.

The data from the US was broadly consistent with the analysis of the Australian data, showing that collisions involving heavy vehicles resulted in more frequent injury to rail occupants and more frequent derailments. The data also showed that rail damage was significantly greater for collisions involving heavy vehicles.

In contrast to the Australian data, the US data showed there were significantly more injuries to the occupants of light road vehicles involved in level crossing collisions, compared to occupants of heavy road vehicles. The difference between these data sources is probably explained by the small number of collisions in the Australian sample, and thus the influence of a single multi-injury accident in the Australia data, which substantially increased the average number of road vehicle injuries in heavy vehicle collisions.

Over-representation of heavy vehicles in level crossing collisions

Previous research and reviews

The Independent Transport Safety Regulator for New South Wales (ITSR) described level crossing statistics for Australia from 2000 to 2009 (ITSR, 2011). The ITSR report showed that heavy vehicles were over-represented in level crossing collisions, accounting for 20% of collisions and 23% of fatal collisions while making up only 2.5% of vehicle registrations and 6% of kilometres travelled. The report also showed that level crossing collisions involving heavy vehicles had double the fatality rate per collision as collisions involving light vehicles.

The industry body Austroads (2010) reviewed level crossing collisions occurring in Australia and New Zealand from 2003 to 2007. This report found that of 405 total collisions, 20% involved heavy vehicles, with 14% being articulated heavy vehicles.

Analysis of level crossing collisions in Canada showed that occupants of heavy vehicles accounted for 40% of all level crossing collision fatalities from 1983 to 2001 (Caird, 2002). This review noted that light trucks, accounting for 27% of fatalities, typically operated in rural and industrial urban areas where there are more level crossings. A later analysis of Canadian accident records found heavy vehicles were overrepresented in level crossing collisions at rural, passive level crossings where the driver of the vehicle did not stop (Rudin-Brown et al., 2014).

Data used to normalise collision numbers by vehicle type

The Bureau of Infrastructure and Transport Research Economics (BITRE) Australian Infrastructure and Transport Statistics - Yearbook 2022 provided estimates of the number of kilometres travelled by vehicle type, by financial year. This data showed that between the financial years 2014-15 and 2021-22, heavy vehicles travelled on average 21.65 billion km each year and light vehicles travelled on average 1.83 trillion km.

The Australian Bureau of Statistics Motor Vehicle Census provided estimates of the total number of registered motor vehicles by vehicle type, by calendar year. This data showed that from 2015 to 2021, there were on average 707,000 heavy vehicles registered in Australia,[23] and about 18.47 million light vehicles.

Comparison of heavy vehicle and light vehicle level crossing collision rates

As described in Australian level crossing collision data, from 1 July 2014 to 30 June 2022, there were 47 level crossing collisions involving heavy vehicles, and 216 collisions involving light vehicles. As shown in Table 14, heavy vehicles were over-represented in level crossing collisions as a function of both the number of collisions per vehicle (around 2 times greater), and the number collisions per kilometre travelled (around 4 times greater).

Table 14: Ratios of collisions by vehicle type to distance travelled and number of registered vehicles

Caution should be exercised in making inferences regarding whether the over-representation of heavy vehicles in level crossing collisions necessarily indicates a greater level of risk. It may also reflect a greater likelihood of encountering level crossings, or a greater likelihood of encountering crossings of higher risk. It is plausible that heavy vehicles are more likely to be operated on rural roads, which are less likely to have level crossings removed through grade separation or be protected by higher level active controls (boom gates). There are no known data describing the rate at which different types of vehicles encounter and traverse level crossings of different types and characteristics, and thus this explanation could not be tested.

Number of level crossing collisions over time

Prior to the establishment of the Office of the National Rail Safety Regulator (ONRSR) in 2013, records of the number of level crossing collisions in Australian jurisdictions were collected by state and territory regulators. The ATSB collected rail collision information from these regulators, and published various statistics including the number of level crossing collisions. The ATSB publication Australian Rail Safety Occurrence Data 1 July 2002 to 30 June 2012 showed that in the decade to July 2012, there was a notable drop in the number of level crossing collisions with vehicles. The number of collisions declined from 82 in the year to July 2002 to 49 in the year to July 2012.

As described in Australian level crossing collision data the national rail safety database was reliable from 1 July 2014 onwards. As such, there was a transitional period from the discontinuation of reporting of state and territory regulator collision statistics in July 2012, to the availability of annual totals commencing 1 July 2015.

There was a substantial drop in the number of level crossing collisions from 49 in the year to July 2012, to 30 in the year to July 2015. From July 2014, the number of level crossing collisions has remained relatively constant, at around 30 to 40 per year (Figure 1). A Mann-Kendall test was conducted on the number of collision per financial year between July 2014 and June 2022 (Figure 2), the test did not identify any statistically significant trend (p = 0.61).

Figure 1: Level crossing collision with vehicle, Financial year totals 2002 to 2022

Figure 2: Monthly level crossing collisions, July 2014 to June 2022, with regression line

Level crossing collision sequence and derailment

Level crossing collisions can either involve the train striking a vehicle (TSV) or a vehicle striking the train (VST). In TSV collisions the impact involves the front of the train striking either a moving or stationary road vehicle, whereas in VST collisions the impact involves a road vehicle striking the side of a moving or stationary train. These different scenarios generally produce significantly different physical forces on the train, affecting the likelihood of derailment (Cherchas et al., 1982). Chadwick (2017) found that VST collisions were disproportionately more likely to result in derailment.

In addition to different direction of the physical forces exerted upon the trains in these scenarios, there is also an expected difference in the speed of the road vehicle at the time of the collision. For instance, in 13 collisions which involved a heavy vehicle stopping foul of the level crossing, the road vehicle was stationary. In many of these collisions, the train drivers identified the stationary vehicle and commenced braking, and the train speed was thus also reduced.

The national rail safety database did not include information about whether road vehicle struck, or was struck by, the train. Of the 49 collisions between trains and heavy vehicles reviewed in this study, there were at least 39 TSV collisions of which 7 (17.9%) resulted in derailments. Of 7 VST collisions, 4 (57.1%) resulted in derailment. Fisher’s exact test showed a significant association between collision sequence and derailment (one-tailed p= 0.046), such that VST collisions were more likely to lead to derailment.

Of 4,886 collisions involving heavy vehicles recorded in the US FRA dataset there were 4,354 TSV collisions, of which 110 (2.3%) resulted in derailment. Of 532 VST collisions, 31 (5.8%) resulted in derailment. Fisher’s exact test showed that VST collisions were significantly more likely to result in derailment (one-tailed p<.001).

Analysis of heavy vehicle level crossing collisions in Australia

This section provides an overview of the characteristics of the 49 heavy vehicle accidents in Australia between July 2014 and August 2022. This section first describes the actions of heavy vehicle drivers associated with the level crossing collisions. The analysis then focuses on some of the factors identified in the study which may have contributed to the actions of the heavy vehicle drivers.

Actions of heavy vehicle drivers

The ATSB reviewed various sources of evidence to determine the circumstances which led to the road user entering the level crossing and not giving way to the train. There were 3 main types of road vehicle actions which precipitated level crossing collisions:

Unsurprisingly, the different actions associated with level crossing collisions varied depending on the type of level crossing protection equipment in use. There was one collision where there was insufficient information to determine the action of the road vehicle driver. The number of collisions associated with each action and the distribution by crossing type is shown in Table 15Table 15: Heavy vehicle driver actions preceding level crossing collisions, by level crossing primary protection type

Collisions at boom gate crossings

All 11 collisions at crossings protected by boom gates involved the road user stopping foul of the crossing. In at least one of these collisions, the driver was unintentionally foul of the crossing due to misjudging the length of their vehicle relative to the available distance on the far side of the crossing.

In 3 collisions, records indicated that the heavy vehicle driver had been unable to exit the level crossing due to unanticipated events. In 2 of these collisions, the heavy vehicle was involved in a collision or near collision with another road vehicle and became stuck. In the other collision, the heavy vehicle reportedly entered the crossing while queueing for an adjoining road, but encountered a mechanical problem and was unable to move from the crossing.

Collisions at flashing light crossings

Most collisions at crossings protected by flashing light signals (8 of 12) involved circumstances where the heavy vehicle driver did not stop before entering the crossing. In 6 of these cases, the heavy vehicle driver observed the flashing lights late on the approach and braked and skidded into the crossing. This meant that at the time of collision, most of the road vehicles were either travelling at a very slow speed or had in fact come to a stop foul of the crossing. In one of the cases, the driver detected the crossing and braked, however records indicated that the vehicle had defective brakes.

In 3 of the 12 collisions the heavy vehicle driver stopped at the crossing and inadvertently proceeded into the path of a train. Various unique factors contributed to each of these collisions:

• In one accident the stop lines at the level crossing were placed too close to the primary level crossing flashing light assembly. This meant that the driver of a passenger bus, who was seated very close to the front of the vehicle, was unable to see the flashing level crossing lights. In that instance, the level crossing also included a secondary flashing light assembly at far side of the crossing, however the bus driver did not look at those lights and inadvertently proceeded into the crossing just before the arrival of a train.
• In another accident, the truck driver heard the train driver sound the train horn and mistakenly thought this was an invitation to enter the crossing ahead of the train.
• In another accident, the truck driver was distracted by something related to the performance of their vehicle and did not pay attention to the level crossing.

One collision involved a heavy vehicle stopping on the crossing (prior to the activation of the flashing lights) and being unable to clear the crossing prior to the arrival of a train due to another heavy vehicle being stuck on the road ahead.

Collisions at Stop sign crossings

In 11 instances, the heavy vehicle driver did not stop at the Stop sign crossing. In 3 cases, the driver braked too late and inadvertently entered the crossing, indicating the crossing was not detected in time to stop. In 4 collisions the drivers attempted to conduct a ‘rolling stop’[24] and thus intentionally did not stop prior to entering the crossing, and probably failed to detect the presence of a train. In one collision, the truck driver reportedly stated they had not stopped or looked for trains before proceeding through the crossing.

In 7 of the 19 collisions at Stop sign level crossings, the heavy vehicle driver stopped their vehicle at the crossing and inadvertently proceeded into the path of an oncoming train.

There was one reported collision where the heavy vehicle driver detected the train and mistakenly determined it was safe to enter the crossing. As such, the other accidents probably indicated problems with either the sighting at the level crossing, the drivers’ behaviour when looking for trains, or the conspicuity of the trains, all of which may have led to the heavy vehicle drivers entering the crossing without identifying a train was approaching.

Collisions at Give way sign crossings

In 5 of the 6 collisions at Give way crossings, the road vehicle driver either did not see the train until they were on the crossing or did not see the train at all. This included one collision where a truck driver did not stop at a level crossing ahead of an approaching train, causing the train drivers to apply emergency brakes. The driver then stopped at an intersection ahead of the crossing, while still foul of the train line.

Errors and violations associated with level crossing collisions

Inadvertent failure to detect level crossing equipment

Research and background

In order to give way to trains at level crossings, road vehicle drivers must first identify that they are approaching a level crossing. The level crossing safety system provides information to drivers about the presence of an upcoming level crossing using roadside signs and roadway pavement markings. In the case of active level crossings, the presence of the crossing is also indicated by boom-gates across the roadway and/or flashing light beacons.

Yeh and Multer (2008) note that some road vehicle drivers inadvertently miss cues relating to the presence of a crossing, reducing their ability to stop in time. The section Factors affecting heavy vehicle driver  provides discussion about some of the reasons for these errors.

Analysis of heavy vehicle level crossing collisions

As identified in Actions of heavy vehicle drivers there were 24 collisions in which the heavy vehicle driver did not stop prior to entering the level crossing. One plausible reason for these collisions was that the drivers did not detect they were approaching a level crossing until it was too late.

To identify the instances where level crossing equipment was not detected, records including police reports, train driver statements, rail infrastructure manager reports and ATSB investigation interviews were reviewed. The ATSB identified:

• There were no instances of heavy vehicle drivers not detecting the presence of a boom-gate controlled active level crossing.
• There were at least 6 collisions where the heavy vehicle driver did not detect that they were approaching an active flashing lights-controlled level crossing until it was too late to stop. In several of these instances, braking occurred before the crossing, however due to the speed and mass of the heavy vehicles there was insufficient distance for them to stop. In one example, an ATSB investigation identified that the road-train truck driver commenced braking at about 180 m from the crossing while travelling at 90 km/h but was unable to stop.
• There were at least 3 collisions at Stop sign level crossings where the heavy vehicle driver did not identify the level crossing until it was too late to stop. In one of these collisions, the heavy vehicle driver reported to police that they were completely unaware of the crossing, and a rail infrastructure manager report identified that sun glare obscured the driver’s vision of the crossing. In the other 2 collisions, the driver identified the level crossing too late to stop.
• There were 5 collisions where the heavy vehicle driver did not stop prior to entering a level crossing controlled by Give way signs. The road rules for Give way sign-controlled crossings do not require a vehicle driver to come to a complete stop, except to give way to trains if one is approaching the crossing. Due to this, the failure of the drivers to stop may have resulted from a failure to detect the presence of the level crossing, or a failure to detect the presence of trains. There was insufficient evidence to determine which of these ‘failures’ contributed to the 5 accidents at Give way sign crossings.

This analysis indicates that in a subset of collisions, heavy vehicle drivers did not detect the presence of the upcoming level crossing. While only a minority of instances, these collisions reflect a dangerous state in the level crossing system. If a driver does not identify the presence of a Passive control crossing, they will not be looking for trains, and there are limited redundant controls to alert them of the requirement to stop. AS1742.7 states that Stop sign crossings are required to be installed when visibility on the road approach to a crossing does not provide adequate visibility for a road vehicle driver to see an approaching train, and this poor visibility will further reduce the likelihood of the train being detected visually by opportunistic (rather than deliberative) scanning. The train horn may provide an aural indication of a requirement to stop, however there are known limitations with the audibility of train horns (see Train horn audibility).

Concerning collisions at active level crossings, the errors were mainly a failure to detect that the crossing was activated, rather than not detecting the crossing. This also presents a highly dangerous condition, since a driver approaching an active control level crossing and perceiving the crossing as not active (lights not flashing), will parse that information as indicating the crossing is safe and no train is approaching. This highlights the importance of ensuring that the signal produced by active level crossings are conspicuous.

Deliberate violation of level crossing rules

Research and background

Part of the safety system for level crossings are the procedural risk controls for level crossing users, including road rules applicable to road vehicle drivers. When road vehicle drivers intentionally disobey the requirements of road rules at level crossings, they greatly reduce the effectiveness of the safety system.

Research has identified that some road vehicle drivers deliberately violate road rules requiring them to stop at level crossings. For example, one study showed that of 22 drivers, 3 did not stop at rural Stop sign level crossings (Beanland and colleagues, 2017). These drivers noted trains were infrequent and suggested there was ample sight distance to look for trains (Stop sign crossings are often installed where there is not adequate distance to look for trains while approaching the crossing).

Gou and Bellavigna-Ladoux (2003) noted that a common form of deliberate non-compliance at level crossings is conducting a ‘rolling stop’. This involves slowing the vehicle until a decision is made to proceed into the crossing, without coming to a complete stop. When conducting a ‘rolling stop’ a road vehicle driver will necessarily spend less time at the stop point for a passive level crossing and therefore will probably conduct less time scanning for oncoming trains, increasing the likelihood of an incorrect decision to proceed into the crossing when it is not safe.

Heavy vehicle drivers may be more likely to engage in ‘rolling stop’ behaviour when approaching a Stop sign level crossing. As described in the ATSB investigation RO-2007-001, Level crossing collision at Back Creek, NSW:

The design standards for level crossings (Appendix B) include a variable for the acceleration capabilities of the design vehicle, and in doing so provide allowance for the increased time required by heavy vehicle drivers to depress and release clutch and engage the required gears to proceed from a stop and through the crossing. This may not, however, translate to heavy vehicle drivers always ensuring their vehicles come to a stop at Stop sign controlled crossings, since they may seek to avoid placing stresses on drivetrain components or simply prefer to maintain forward movement.

Another common violation occurs when road vehicle drivers enter a level crossing and stop foul of the rail tracks. A common scenario is the driver entering the crossing while the road ahead was blocked by other traffic, mistakenly anticipating traffic ahead would clear and they will be able to proceed through. This is contrary to road traffic laws. For example, the Australian road rules (model law) states:

These violations have been attributed to various factors; road vehicle drivers may perceive there to be a low level of risk associated with entering a crossing and waiting for traffic to clear. These actions may also be influenced by social pressure and perceived social norms (Yeh and Multer, 2008). In one study, 30% of drivers reported that they would violate boom gate crossing rules if they did not detect a train and they saw another driver do so (Witte and Donohue, 2000).

Analysis of heavy vehicle level crossing collisions

In at least 4 collisions, the heavy vehicle drivers engaged in deliberate non-compliance with level crossing rules for Stop signs by conducting a ‘rolling stop’ on approach to the crossing. In another collision, the heavy vehicle driver did not stop at a Stop sign and did not look for trains. These actions increased the risk of collision by reducing the likelihood that the drivers would identify the presence of trains.

There were at least 6 collisions where the heavy vehicle driver intentionally entered the level crossing when traffic or another blockage prevented them from proceeding clear of the train lines. This did not include instances where the driver mistakenly thought their vehicle was clear of the crossing, or instances where the driver had an accident or breakdown on the crossing.

In an additional 3 collisions, the heavy vehicle driver intentionally entered and stopped foul of the crossing, but did not exit the crossing in time to prevent a collision. In these 3 accidents there was no evidence of a blockage preventing the heavy vehicle from clearing the crossing and were considered intentional non-compliance with level crossing rules for the purpose of this analysis.

In addition, there were 2 collisions where the driver of the heavy vehicle was engaged in high-risk behaviour prior to unintentionally entering the level crossing or unintentionally stopping foul of the crossing. In one instance, the driver was distracted by their mobile phone, and in another the driver was found to be drug affected. These accidents were not considered intentional violations of level crossing rules in this analysis; these drivers did not intentionally enter the level crossing.

Failure to detect trains at passive control crossings

Research and background

At passive control crossings, road vehicle drivers must visually search for and detect the presence of a train to determine when they can and cannot proceed through a crossing. There are no recovery controls to prevent a collision if a road vehicle driver does not detect that a train is approaching.

Road vehicle drivers sometimes do not look for oncoming trains when approaching a passive control crossing. Research using head movement measurements of heavy vehicle drivers found that less than 60% looked in at least one direction of the train line when approaching a passive control level crossing (Ngamdung and da Silva, 2012). Failure to look for trains may be associated with a number of factors, including not identifying the presence of a crossing, distraction or preoccupation, or a low expectancy of the presence of a train at the crossing.

Even when road vehicle drivers look in the direction of approaching train, they may not detect the train nor identify a requirement to stop. Rudin-Brown and colleagues (2014) identify that many level crossing collisions result from so-called ‘Looked But Failed to See’ errors.

Analysis of heavy vehicle level crossing collisions

As identified in Actions of heavy vehicle drivers there were 26 collisions at passive control level crossings. Of these collisions, at least 2 involved the heavy vehicle driver detecting the train before entering the crossing:

• In one instance, the driver of the heavy vehicle stopped for a Stop sign level crossing and identified that a train was nearby. The train’s lead locomotive cab was unoccupied, and was conducting an indexing movement across the crossing at low speed. The truck driver incorrectly determined that they could transit the crossing safely, and the train scraped the side of the truck prior to it clearing the crossing.
• In one instance, the driver approached a Stop sign level crossing and, according to the rail operator report for this collision, the truck was unable to stop for the crossing due to a mechanical problem.

Concerning the other collisions at passive control level crossings, there was limited information to determine whether the heavy vehicle driver looked for trains and detected the presence of a train before proceeding into the crossing. Heavy vehicle drivers were almost never interviewed, except in collisions which were investigated by the ATSB. Driver statements were sometimes included in police reports; however drivers may be disinclined to inform the police if they had not looked for trains.

While there was very limited direct evidence concerning whether a heavy vehicle driver looked for trains, the ATSB considered that an indirect indicator of heavy vehicle drivers attempting to comply with the requirement to look for and give way to trains was whether the heavy vehicle slowed or stopped during the approach to the crossing. However, it is acknowledged that this indirect evidence cannot rule out the possibility that some drivers may have slowed when approaching the level crossing due to other factors, such as the road condition near the crossing, or to accommodate the type and weight of their load.

The ATSB reviewed rail operator, rail infrastructure manager and police reports to classify the braking behaviours of heavy vehicles approaching passive control crossings.

• In at least 12 collisions, the driver either slowed or stopped while approaching passive control crossings but either did not detect the train, or deliberately entered the crossing ahead of the train.
• In at least 4 collisions, the driver did not slow or stop for the crossing until too late. In one of these collisions, the ATSB report found the driver did not approach the crossing with sufficient caution to stop after noticing the train. In another collision, the rail infrastructure manager report stated the vehicle was travelling too fast to stop at the crossing. In another collision, the driver stated they did not detect the presence of the crossing, and only commenced braking after seeing the train shortly before the collision.
• In one collision, the rail operator report stated that the heavy vehicle driver reported that they had not slowed or looked for trains at the Stop sign crossing.
• In 7 collisions, there was insufficient evidence available to determine whether the heavy vehicle slowed on approach to the passive control level crossing.

The analysis therefore identifies that in at least 46% (12 of 26) of collisions the observed braking behaviour indicated that the heavy vehicle drivers made some attempt to comply with the requirement to look for and give way to trains, however probably did not detect the presence of the train.

An alternative explanation in these cases was that some the heavy vehicle drivers who slowed or stopped when approaching passive control level crossings did identify the presence of a train, but elected to enter the crossing, in an attempt to ‘beat the train’ through the crossing. There was no direct evidence of any heavy vehicle drivers deliberately proceeding in front of an approaching train, although drivers may be unlikely to make admissions of such behaviours to police or to rail operator investigations. In 2 cases, the heavy vehicle driver was fatally injured in the accident and there was limited information concerning whether they had observed the train prior to entering the crossing. In 4 cases, the heavy vehicle drivers stated that they had looked for trains prior to entering the crossing. In other cases, other circumstances related to the accident indicated it was unlikely the heavy vehicle driver had deliberately entered the crossing. Considering all the available evidence of the 12 cases where heavy vehicle drivers slowed or stopped while approaching passive control crossings, the ATSB determined the drivers had probably not detected the presence of a train.

Factors affecting heavy vehicle driver behaviour at level crossings

Overview and prior research

The analysis of level crossing collision data showed that collisions typically occurred in fine weather, in daylight, on dry, sealed roads. Previous analysis found that most level crossing accidents did not involve alcohol or excessive speed (ATSB, 2002), which are common causes for other road accidents (OECD, 2021).

The majority of collisions probably involved some form of unintentional lapse, where the heavy vehicle driver did not identify a train was approaching the crossing. Even in the subset of collisions where a deliberate violation of road rules was identified, the heavy vehicle driver probably intended and expected to clear the crossing safely.

The safety systems approach to accident analysis seeks to understand the contextual factors associated with individual errors and violations. This involves identifying factors that exist within the system which increase the likelihood of errors and other failures (latent conditions). For the level crossing safety system, this includes considering how the experiences and tasks of road users shape their performance at level crossings. It also includes considering the design of vehicles, trains and level crossing equipment, and whether these support the tasks of the human operators at level crossings (road vehicle and train drivers).

Familiarity and expectancy

Research

When drivers become familiar with a particular crossing or a particular type of crossing, and when the driver has previously not observed trains at that crossing (or type of crossing), an unconscious expectancy for no trains at that crossing or that type of crossing may form (Rudin-Brown and colleagues, 2014). Researchers have argued that drivers generally expect there to be no trains present at level crossings (Eck, 2002), and that these expectations are ‘the greatest challenge’ in overcoming safety problems at passive level crossings (Salmon and others, 2013) and the ‘root of unintentional noncompliance at…level crossing’ (Eck, 2002).

Research has shown that drivers familiar with a level crossing are more frequently involved in level crossing collisions than drivers unfamiliar with an area (Abraham and colleagues, 1998). A coronial investigation into 12 fatal level crossing collisions in Victoria found that all except 3 drivers were very familiar with the crossing and all but one never or rarely saw a train at the level crossing (Coroner’s Court of Victoria, 2013).

There are several ways that this low expectancy of trains can contribute to level crossing collisions. Low expectancy for trains may influence deliberative, planned behaviour where a driver enters a level crossing contrary to the requirements of road rules. Reason (1990) identifies that routine violations of rules are often the product of environments where violations are infrequently punished, which may be taken to mean formal punishment in the case of law enforcement, or other negative consequences such as collisions. As Yeh and Multer (2008) summarise, a low expectancy and low frequency of trains at level crossings may cause drivers to simply disregard crossing protection equipment.

The other way low expectancy for trains can influence level crossing collisions is at the unconscious level, affecting how road vehicle drivers scan for and detect important information about the crossing and the presence of trains. Reason (1990) identifies that people engaged in well-practiced, routine tasks are vulnerable to unintentional slips of attention. In these contexts, attention and behaviour is highly influenced by the ‘motor schema’ or ‘script’ for the task, and there is a high likelihood that an operator will miss cues which indicate a need to divert from the typical routine.

The task of driving a road vehicle is generally highly-practiced, and occurs in roadway environments where other demands and distractions are often prevalent. In this context, road vehicle drivers are required to depart from the active and dominant motor schema of continuing to drive along the road, and adopt a motor schema of looking and preparing to stop for trains. For motorists with a low expectancy for encountering a train at a crossing, there is a high likelihood that they may miss cues which identify they need to stop for trains.  

Other psychological theories identify that experiences form the basis for ‘schemas’ or ‘mental models’ of the task environment. These mental models influence where a person will search for information, what they are looking for, and which information they will detect (Wickens and McCarley 2008; Wickens and others 2013). Drivers with a low expectancy of trains may therefore be less likely to look for trains, or look for activated flashing lights. Even in situations where a driver looks directly at a train or flashing light assembly, they may not detect the requirement to stop and proceed into the crossing, reflecting a so-called ‘looked-but-failed-to-see’ error.

Analysis of heavy vehicle level crossing collisions

As described in Errors and violations associated with level crossing, 9 accidents were due to the heavy vehicle driver intentionally stopping foul of a level crossing. There was insufficient evidence to establish whether any of these drivers were familiar with the level crossing, or what expectancy they had when entering the crossing. It is possible, however, that some or all these drivers previously queued over the same crossing or other intersections, with no negative consequences. It is also possible that these drivers had observed other drivers queueing over level crossings, normalising the behaviour and reducing the expectancy of negative consequences.

There were 12 collisions where the ATSB identified that the heavy vehicle driver was familiar with the level crossing prior to the collision with the train, and all of these involved the driver either not stopping at the crossing or stopping and proceeding into the path of the train. There were 6 collisions where the heavy vehicle driver was familiar with a passive control level crossing and did not detect the presence of the train. In 5 collisions, the heavy vehicle driver was familiar with a crossing protected by flashing lights and did not detect that the lights were activated.

The heavy vehicle drivers were typically engaged in driving for business or employment, and the collisions often occurred on routes they traversed several times a day or week. Some examples included:

• One driver reported that they travelled across the same level crossing about 20 times per day for work, and was not expecting a train.
• One driver reported they had been driving the same route for 2 months and the train they collided with was the first train they had seen at the level crossing.

It was not possible to precisely describe the effects of familiarity for each of these 12 collisions. However, it is highly likely that in some collisions the drivers’ familiarity with the level crossings and low expectancy for encountering trains affected their attention to and perception of the crossing environment. With a low expectancy of trains, the drivers may have either not allocated sufficient attention to the crossing or have looked but not detected a requirement to stop.

In one collision the heavy vehicle driver entered a level crossing after identifying that the level crossing lights were flashing and detecting the train. The driver heard the train driver sound the train horn and mistakenly thought this was an invitation to enter the crossing ahead of the train. They reported to police that they had previously been ‘let through’ the crossing in similar circumstances, and therefore had an expectancy that they could cross ahead of the train.

Distraction and divided attention

Research

Distraction occurs when a driver’s attention (meaning where the driver is looking, what they are manipulating/touching, and what they are thinking about) is diverted from activities critical for safe driving towards a competing activity (Parnell and others, 2016). There is a significant body of evidence demonstrating that distraction impairs driving performance and contributes to accidents (Young and others, 2007).

The task of driving a road vehicle often requires attending to complex road environments. Due to a limited ability to attend to multiple sources of information at once, road vehicle drivers operating in complex or cluttered areas (such as where there are multiple intersections, signs, or road users) may be less likely to attend to and detect trains (Rudin-Brown and others, 2014).

Reviews of level crossing collisions have identified that distraction can be a contributory factor to driver non-compliance (Rudin-Brown and others, 2014). In-cab studies of heavy vehicle drivers have shown that drivers sometimes attend to other tasks (including texting or eating) while negotiating level crossings (Ngamdung and da Silva, 2012), or may be distracted by factors at the crossing such as poor surface conditions (Eck, 2002).

Analysis of heavy vehicle level crossing collisions

Records indicated that at least 6 of the heavy vehicle drivers were probably distracted prior to the collision, or were dividing their attention between driving the vehicle and another task or thought. In some of these instances, the driver was reportedly focussed on other traffic or complicated road signage, and did not detect the level crossing flashing lights or the approaching train. In one example, an ATSB investigation obtained in-vehicle video footage which showed the truck driver was distracted by re-affixing a mobile phone mount which had fallen from the truck windscreen. The truck driver did not notice the flashing active crossing warning lights and proceeded into the crossing, colliding with a freight train.

Obstructed vision due to vegetation, sun glare and poor crossing lighting

Research

For a road vehicle driver to detect an oncoming train at a passive level crossing, the train needs to be visible within their field of view. In some instances, however, the design and maintenance of level crossings is such that the driver’s view is obstructed.

Another visual problem encountered by road vehicle drivers approaching a level crossing is disabling sun glare. Disability glare occurs when light enters the eye and ‘washes out’ the image being perceived (Sanders and McCormick, 1993). The disabling effect of glare is greatest when the sun is in the direct line of sight of the driver. Thus, sun glare is greatest at the times just before sunset and just after sunrise, when the sun is low in the sky and thus objects which are being viewed at ground level fall in a narrower angle relative to the sun.

After sunset, night-time darkness affects the ability of drivers to safely negotiate level crossings by reducing the availability of visual cues, particularly for passive control crossings. Where level crossings are unlit, level crossing signage may be difficult to detect. Yeh and Multer (2008) note that illumination of level crossings improves the detection of the crossings at night.

Analysis of heavy vehicle level crossing collisions

In at least 9 collisions reviewed by this study, the view of the heavy vehicle driver was probably obstructed by nearby vegetation. In at least 8 instances, vegetation probably obstructed visibility of the rail track, which may have reduced the ability of the driver to detect oncoming trains. In one instance, vegetation obstructed the visibility of the rail track and the level crossing protection equipment.

In one collision, the rail infrastructure manager and police reports identified that the driver of the heavy vehicle was probably unable to detect the presence of the level crossing due to sun glare.

In another collision, the rail infrastructure manager identified that a Stop sign was located in a dark industrial area, with poor lighting on the crossing itself and contrasting bright lights from surrounding industrial installations and other road traffic. The infrastructure manager report found that when a heavy vehicle approached the crossing at night, the poor lighting conditions reduced the driver’s ability to detect an approaching train.

Obstructed visibility due to vehicle design

Context

In addition to environmental obstructions, the visibility of trains and level crossing equipment may be affected by vehicle design characteristics. Heavy vehicles often have large ‘A’ and ‘B pillars, planar mirrors, and other structures like exhaust snorkels. Research has shown that restricted fields of view in heavy vehicles are a common cause of other road accidents (Blower, 2007; Niewoehner and Berg, 2005).

The Australian Design Rule 93/00 – Forward Field of View specified the allowable restrictions within the drivers’ forward 180° field of view for passenger and heavy vehicles supplied to the Australian market.[25] The regulations did not prescribe any requirements for field of view behind the driver.

The design standards for level crossings (Australian Standard AS1724.7:2016) required that the sighting opportunity available to road users is provided at visual angles which do not require excessive head movement or sight obstruction by the vehicle itself. The standard states that for the sighting distance when stopped at a level crossing, the maximum allowed viewing angles are 110° to the left and 140° right.

The combination of vehicle design which does not prohibit restricted visibility behind the driver seated position, and crossing design which allows for rail traffic to approach from obtuse angles (greater than 90°), leads to a potential zone of restricted visibility where the driver may need to lean forward to view along the train track.

Analysis of heavy vehicle level crossing collisions

In at least 5 collisions reviewed in this safety study, the design of the heavy vehicle cab probably restricted the driver’s view of the crossing equipment or train. These included 3 collisions which had previously been investigated by the ATSB:

• RO-2015-016: The ATSB found that the truck ‘A’ pillar and air snorkel probably restricted the driver’s view of the flashing lights as the truck approached the crossing.
• RO-2016-009: The ATSB found that the truck driver’s view of the track when looking left was restricted by the structure of the cab and the absence of windows behind the driver. When seated in an upright position, the viewable area was limited to 90°, meaning only 29 m of track was visible. This could be extended by up to 104° (60 m) by hunching forward.
• RO-2017-011: The ATSB found that the truck driver would not have been able to see the approaching train from their stopped position, due to their line of sight being obscured by the truck’s B-pillar.

In another collision, the shallow-nosed design of the bus cab meant that when the driver was stopped at the stop line, they were very close to the stop line and had a restricted view of the flashing crossing lights on the near-side of the crossing, contributing to them entering the crossing into the path of a train. In the other collision, the driver identified that large air cleaners on their vehicle may have obstructed vision of the train at the passive control level crossing.

This analysis demonstrated that the visibility of some heavy vehicle drivers was restricted by objects around the level crossings, the design of the heavy vehicle and the crossing, and the environmental conditions at the time of the collisions.

Train horn audibility

Australian Standards and other requirements

Locomotives operating in Australia must be equipped with train horns, which are used to ensure individuals in and around the rail corridor are aware that rail traffic is approaching. The Rail Industry Safety Standards Board (RISSB) Code of Practice for Rail Traffic Horn Use stated that:

The Australian Standard for Railway Rolling Stock Audible Warning Devices (AS 7532:2016) described requirements for the audibility of train horns:

• The country warning device must produce at least 88 dB at 200 m ahead of the rolling stock, and at least 106 dB at 30 m ahead of the rolling stock.
• The town warning device must produce at least 90 dB at 100 m from the rolling stock and 101 dB at 30 m from the rolling stock.

AS 7532:2016 did not specify the types of train horns accepted for use, or the frequencies at which the train horn must produce sound.

The RISSB Code of Practice for Rail Traffic Horn Use stated that activating the train horn was a requirement at passive control level crossings, and optional at active control crossings. The code of practice also required that the train horn must be sounded at the whistle board, where placed, and may be sounded at other locations including during the approach to and on the crossing.

Research on effectiveness of train horns

Research examining level crossing collisions in the US between December 1995 and August 1996 found that 55 of 60 train drivers sounded the locomotive horn prior to the collision, but only 4 of 14 road vehicle drivers reported hearing the horn (described in Yeh and Multer, 2008). In a 2013 coronial review of 12 fatal level crossing accidents in Victoria, the Coroner noted that none of the drivers had heard the locomotive horn (Coroner’s Court of Victoria, 2013). These reviews highlight that in many collisions it is evident that train horns were unreliable for alerting road users to the presence of a train.

Supporting the utility of train horns, Yeh and Multer (2008) identified that initiatives prohibiting the use of train horns (whistle bans) in US jurisdictions have led to increased rates of level crossing collisions. For example, they report analysis conducted by the FRA in 1995 was reported:

Follow-up analysis conducted by the FRA (2000) found that:

Several laboratory studies have investigated the acoustic qualities of train horns, and the audibility of train horn sound in simulated conditions. Findings from this research include:

• Different types of train horns produce different patterns of sound. 5-chime horns were found to produce a much greater volume of sound at higher frequencies (above 800 Hz) than 3-chime horns (Rapoza and Raslear, 2001).
• Train horn sound is attenuated as a function of the distance of the train from the vehicle, consistent with the inverse square law for sound. Because a vehicle travelling at a greater speed will need to detect the train from further away in order to stop, the train horn must be proportionally louder (proportional to the square of the distance between the train and road vehicle).
• The level of sound available to road vehicle drivers is affected by the sound-attenuating properties of the vehicle body, referred to as insertion loss.
• Train horn sound is also attenuated by whether the road vehicle windows are open or closed, whether the engine is running, and whether the radio and/or fan is on (Rapoza and Raslear, 2001; Casali and others 2002; Dolan and Rainey, 2005).

There were mixed findings regarding the detectability of train horns.

• Raslear and Rapoza (2001) used a probability model to predict the likelihood that road vehicle drivers would detect an approaching train in time to prevent collision. The model predicted that a road vehicle driver approaching a passive control level crossing would almost always detect a 5-chime warning horn. However, a 3-chime warning horn would only be detectable 75% of the time when the train was travelling at 32 km/h, dropping to 25% of the time when the train was travelling at 64 km/h.
• Dolan and Rainey (2005) conducted a laboratory study which involved producing simulated train horn sounds at different volumes, along with simulated background noises to replicate different vehicle conditions. They found that 50% of participants could detect the simulated train horn sound at a volume of 10 dB below the simulated background noise. One limitation of the applicability of this research is that the participants were not driving a vehicle and were primed to listen for the train horn signal.
• Casali and others (2002) measured the sound produced by a 5-chime train horn, and the sound attenuating properties of a sample of 1990s model trucks under different operational conditions (engine on/off, windows up/down, radio on/off). This research concluded that the noise produced by the train horn only exceeded the ‘masked threshold’ (being 13 dB louder than background noise) when the engine was at idle and the windows were down.

In summary, there is no known research which has examined how frequently real drivers respond to train horns in real driving conditions. Consolidation of the research indicates that the requirement to use a train horn improves the safety of level crossings overall, however collision case-studies indicate that there are numerous instances where the train horn is not effective for alerting drivers to the presence of a train. There is a research gap, therefore, in identifying the circumstances in which train horns are not effective, and how often train horns are not effective for preventing collisions.

Analysis of heavy vehicle level crossing collisions

Records indicated that in at least 44 of the 49 level crossing collisions reviewed in the study the train crew sounded the horn as required prior to the collision. There were at 2 instances where the horn was not sounded as required at the whistle board, and 3 instances where there was insufficient information to determine whether the horn had been sounded.

Considering the effectiveness of the train horn for alerting heavy vehicle drivers to the presence of trains, the ATSB noted that:

• There were 13 collisions which involved the heavy vehicle driver stopping foul of the crossing. In most of these, the heavy vehicle driver was not able to exit the crossing due to being blocked by traffic or another form of impediment, and thus detecting the train via the train horn was unlikely to have prevented these collisions. In 3 of the collisions the ATSB did not identify evidence of a blockage preventing the heavy vehicle from clearing the crossing.
• In 3 collisions, the heavy vehicle driver had identified the presence of a train but did not stop. These included 2 collisions where the heavy vehicle driver encountered a mechanical problem and was unable to stop, and one collision where the truck driver heard the train horn and mistakenly interpreted this to be permission to entering the crossing. The detectability of the train horn was not considered to have affected these collisions.
• There were 3 additional collisions where there was insufficient information to determine whether the vehicle driver detected the presence of the train.

Excluding these instances, the ATSB identified 25 collisions where the train horn was sounded and not detected by the heavy vehicle driver. The heavy vehicle drivers, not detecting the presence of a train, proceeded into the path of the train resulting in collision. It is possible that had the train horn, or another warning, been more conspicuous to the heavy vehicle drivers, then these 25 collisions may not have occurred.

The safety study reviewed collisions only, and did not examine the number of near misses and other instances where heavy vehicle drivers were alerted to the presence of the train by the train horn.

Other audible warning devices

Australian Standard AS1742.7 (Railway level crossings) states that flashing light signals may include the provision of audible warning devices. Further, the standard requires that where active control of pedestrian traffic is provided (red flashing man signal), an audible signal shall be provided. The safety study did not analyse the effectiveness of other audible level crossing warning devices, such as audible ‘bells’ provided at some level crossings. The ATSB observes, however, that such audible warnings are produced at a much lower volume than locomotive horns, and thus are likely to be less audible to approaching road vehicles. Audible level crossing signals are primarily engineered to be effective for alerting pedestrians.

Visual conspicuity of trains

Research

Due to the safety system for passive control level crossings relying on road vehicle drivers visually detecting the presence of a train in order to identify a requirement to stop and give way, there has been substantial interest in the extent to which the visual characteristics of trains make them difficult to detect. The concept of conspicuity refers to the material characteristics of an object which affect the likelihood it will be detected. The greatest determinant of visual conspicuity is the level of contrast between the object and its surrounding environment.

Trains are often constructed with dark colours, and may be poorly lit, reducing their conspicuity for road vehicle drivers, particularly at night (Rudin-Brown and others., 2014; Yeh and Multer, 2008). A review conducted by the Australian Centre for Rail Innovation (ACRI) identified Australian case studies where factors such as dull colour schemes, dirty train exterior and low contrast between the train colour and the surrounding environment may have reduced the conspicuity of freight trains (ACRI, 2022). The ACRI freight train visibility review identified 30 opportunities to increase the conspicuity of trains, of which 2 were carried forward to field testing (flashing train beacons and conversion of headlights from halogen to LED). The results of this testing showed that LED conversion of locomotive headlights resulted in improved visibility in misty conditions only, with insignificant improvement in clear weather conditions. The beacon light was only effective at improving visibility in situations where the train and observer were close to the crossing, and the level crossing angle was obtuse (between 90° and 180°) (Kassa, Wan and White, 2023). Other research has examined the effects of some common treatments for improving train conspicuity:

• Studies have shown that trains equipped with auxiliary alerting lights (additional to the train headlight) are detected at greater distances (Carroll et al 1995).
• Trains which have reflectorised markings installed on freight cars (wagons) are detected at greater distances than unmarked cars (see Edquist and others (2009), for a review).
• Several studies have examined the benefits of strobe lighting on trains, however only small effects have been observed (Cairney, 2003).

In addition to poor illumination, the visual image of a freight train available to a road vehicle driver approaching a level crossing may provide a low likelihood of detection. When a driver is approaching a level crossing and attending to the road, an approaching train will be in the driver’s peripheral field of view. There will often be no visual cues indicating the presence of a train in the driver’s central (foveal) field of view, where detection of objects is most likely (Edquist and others, 2009; Yeh and Multer, 2008).

The human perceptual system is particularly adapted to detecting movement, and vision in the peripheral field of view is particularly sensitive to movement. Unfortunately, due to the geometry of a collision, a train will typically present as an unchanging retinal image to the driver. That is, the train will not appear to move across the driver’s retina when it is on a collision course with the road vehicle driver (Rudin-Brown and others, 2014). These perceptual challenges are similar to those described in the ATSB report

Relevant industry standards

Australian Standard AS 7531:2015 Lighting and Visibility described the requirements for rolling stock lighting and visibility. This standard required that all locomotives and self-propelled passenger rolling stock have at least one white headlight on each leading end. For new and modified rolling stock, the standard required locomotives and self-propelled rolling stock have active visibility lights, which were required to flash for at least 15 seconds after the horn is sounded. The standard stated that the primary purpose of these lights was to enhance the visibility of the train from the perspective of a driver of a road vehicle approaching a crossing.

AS7531:2015 also required all new and modified locomotives and lead vehicles of passenger trains to have high-visibility colour livery applied. Under this requirement, at least one square metre of the forward-facing area of locomotives and passenger rolling stock was required to be yellow, orange, red or white.

In December 2023 (after the study period of 1 July 2014 to 31 August 2022), the Rail Industry Safety and Standards Board approved AS7531:2023. This version of the standard included additional rolling stock lighting and visibility design principles, and provided additional requirements for high-visibility livery. The lighting and visibility design principles added to the standards in the 2023 revision included the following:

In January 2024, ONRSR announced that it would develop a Code of Practice for train visibility in Australia, with a final draft expected by mid-2024. The intent of this code was to ‘assist rail transport operators to strengthen the overall safety management systems that underpin their operations where trains interact with people, drivers and vehicles - with an emphasis on risk controls for train visibility’. ONRSR stated that it would consider the Code of Practice when conducting compliance activities, and that the code would be admissible to proceedings related to compliance with the Rail Safety National law.

Analysis of heavy vehicle level crossing collisions

The ATSB reviewed operator reports and other records to identify how conspicuity equipment such as headlights, visibility (ditch) lights and livery had been utilised for the trains involved in the 49 collisions with heavy vehicles reviewed in this study. Overall, this information was reported infrequently, with key observations being:

• In 24 collisions, the records indicated that the train headlight was on prior to the collision with the vehicle, while in one collision, records indicated the headlight was off. In 24 collisions there was insufficient evidence to establish status of the headlight.
• For 8 collisions, records indicated that the train had visibility (ditch) lights installed, whereas in 4 collisions the train did not have visibility lights. There were 37 collisions where information about the train visibility lights was not reported.
• In 10 collisions, operators reported on the installation of reflective delineators. Four trains had reflective delineators installed on rollingstock, and 6 did not.

Of the 26 collisions at passive control level crossings, 2 occurred at night and in both of these cases the train had its headlights activated. In one of these collisions, the train was being operated in the reverse direction, meaning the train headlights were not effective at illuminating the train in the direction of travel towards the crossing.

In summary, due to limitations in available data from operator reports and other documents, this study was not able to evaluate whether trains involved in level crossing collisions were equipped with the lighting and other visibility equipment required by Australian standards. Furthermore, since this study only examined trains which were involved in collisions, it was not possible to identify factors associated with greater of poorer conspicuity, or for that matter the effectiveness of different types of equipment used to enhance train conspicuity. This is discussed further in Study limitations.

Other observations which may be useful for further analysis of train conspicuity include:

• Very few of the collisions reviewed in this study occurred at night, when problems associated with conspicuity are probably greatest.
• The majority of collisions (at least 39 of 49 collisions) involved the train striking the heavy vehicle, indicating that problems associated with train conspicuity are more likely to involve the conspicuity of the locomotive, rather than the other rollingstock.

Analysis of level crossing safety systems

Curved road approaches

Standards and other guidance relevant to placement of crossings on curved road approaches

Australian Standard for level crossing design

The criteria for the placement of level crossing protection equipment were described in Australian Standard AS 1742.7:2016 Manual of uniform traffic control devices. AS 1742.7 stated that level crossings:

The standard required that if a level crossing was located on a curved road, then appropriate curve signs were to be used, or alternatively additional level crossing warning signage may be placed along the curve. The standard further stated that:

AS 1742.7 sought to ensure that the placement of the primary active level crossing control device (such as the flashing light assembly) provided sufficient time and distance for the road user to identify a crossing ahead and stop after identifying the control device is activated. This distance was referred to as S₁ or the safe stopping distance (SSD).

Sighting distances described in AS 1742.7, and shown in Figure 3, were defined as:

• S₁, the minimum road distance which must be available to the road design vehicle, at the point the driver is able to detect a requirement to stop prior to the nearest rail.
• S₂, the minimum distance of a train from the crossing at which a road vehicle driver at distance S₁ from the crossing can proceed at speed and safely clear the crossing ahead of the train.
• S₃, the minimum distance of an approaching train from the centre of the crossing, when the driver of the road vehicle, stopped at the crossing, must first see an approaching train in order to safety cross the tracks.
• X_L, sighting angle (left).

Figure 3: Sighting distances for level crossings described in Australian Standard AS 1742.7:2016

Source: Image created by ATSB, illustrating concepts described in AS 1742.7:2016

AS 1742.7 provided guidance ‘in order to ensure that a motor vehicle driver can see along the prescribed sight triangles without excessive head movement’. This was achieved through the provision of maximum sighting angles for the S₂ and S₃ distances.

AS 1742.7 provided instructions for calculating S₁ at each crossing, considering various factors related to the expected road user and the road construction (the formula for calculating S₁ is provided in Appendix B). The standard did not require additional S₁ distance for crossings placed on or after curved road approaches.

Procedural guidance for level crossing sighting surveys

Level crossing sighting surveys are conducted to determine if level crossings comply with requirements including those described in AS 1742.7. The Australian Level Crossing Assessment Model (ALCAM) Level Crossing Assessment Handbook was produced by the National ALCAM Committee as a guide for trained surveyors, providing methods for carrying out ALCAM surveys of level crossings in Australia and New Zealand. These procedures stated that to measure the available sighting distance for primary level crossing protection equipment (S₁), surveyors should:

• Drive all approach roads in the vicinity of the crossing to obtain the maximum sighting distance when the crossing control can be clearly seen, and record the available sighting distance available for each approach.
• Calculate the required safe stopping distance position for the roads passing through the crossing. If there are side roads turning towards the crossing or if the crossing is approached from a nearby intersection, safe stopping distances for these roads were also to be determined.
• Compare the available and required (calculated) safe stopping distances.

The handbook also identified that additional warning signs may be installed where the road approach to level crossings is curved, observing that ‘duplicated advance warning signs are generally placed on curved road approaches where visibility to the left-hand sign assembly is restricted by roadside vegetation, terrain or structures’.

Level crossing collisions

Of 6 collisions where the road driver braked too late to stop at a flashing light level crossing, 5 occurred at crossings on or following a curved road approach. All 5 were right curves. None of these collisions occurred at crossings with active advanced flashing lights (RX-11) installed. Three of the collisions had previously been investigated by the ATSB:

• ATSB investigation RO-2015-016, Level crossing collision between freight train 8834N and road-train truck, Tullamore Rd, Narromine, NSW, on 23 September 2015. This investigation found that ‘The viewing angle approaching the railway crossing (from the southwest) through the right-hand curve meant that at higher road speed there was reduced opportunity for the truck driver to identify that the flashing lights were operating’.
• ATSB investigation RO-2017-005, Level crossing collision between freight train 8426N and road-train truck, Cobb Highway, Ivanhoe, NSW, on 11 July 2017. This investigation noted that it was possible the driver did not identify the flashing crossing lights due to a focus on negotiating the curved approach to the crossing.
• ATSB investigation RO-2021-003, Level crossing collision between freight train 2C74 and road-train truck Yarri Road, Parkeston, Western Australia, on 22 February 2021. This investigation noted that the truck driver’s sighting of the flashing crossing lights was through a curve. With the truck driver distracted by another activity and possibly only looking directly ahead of the vehicle, they were probably not effectively looking through the curve to the crossing lights. Figure 4 illustrates the driver’s view of the level crossing while navigating this curved road.

Figure 4: Image showing overhead and driver view of level crossing relative to vehicle line of travel, from ATSB investigation RO-2021-003

Source: ATSB investigation RO-2021-003, Level crossing collision between freight train 2C74 and road-train truck Yarri Road, Parkeston, Western Australia, on 22 February 2021.

Records from ALCAM surveys showed the recorded S₁ distances for the road approaches travelled by the heavy vehicles, for the 5 collisions in this study which occurred on curved road approaches to flashing light level crossing (no boom gates installed). The ATSB reviewed satellite imagery to identify the position of the road vehicle at the point at which the S₁ distance was identified, and the visual angle from that position to the level crossing protection equipment (flashing lights). These distances and angles are shown in Table 16.

Table 16: Visual angle identified for sighting of flashing lights at selected level crossing collisions at crossings with curved road approaches

Level crossing collisions investigated in other jurisdictions have also been attributed to the effects of curved road approaches, with examples including:

• Canadian Transportation Safety Board Railway Investigation Report R13T0192, Crossing collision involving passenger train and double decker bus on 18 September 2013. This collision occurred at a level crossing protected by flashing lights and boom gates. The investigation identified that ‘while negotiating the … [left] curve on the approach to the crossing, the [bus] driver would have generally gazed toward the tangent point at the centreline of the road and made anticipatory glances toward the occlusion point where the view of the road ahead was obstructed by trees, shrubs, foliage, and roadway signage. In addition to distractions that likely influenced the driver, the additional driver workload associated with negotiating the left-hand curve[26] on approach to the crossing likely decreased the driver’s ability to detect the activated (flashing lights)’.
• Canadian Transportation Safety Board Railway Investigation Report R16D0092, Crossing collision involving passenger train and tractor-trailer 20 September 2016. The collision occurred at a crossing protected by flashing lights and boom gates. The investigation noted that the left curve approaching the crossing obstructed visibility of the level crossing equipment, and the crossing only became completely visible at 730 ft (223 m) from the crossing. The report found that ‘While the tractor-trailer driver was negotiating the curve, his visual attention was probably focused more on the outside of the curve rather than far ahead. Therefore, the driver did not immediately notice that the warning system was activated.’ The investigation noted that once the curve straightened, the driver had only 500 ft (152 m) to sight the crossing, which was insufficient distance to stop the heavy vehicle.
• US National Transportation Safety Board Highway Accident Investigation Report HAR1402, Highway-Railroad Grade Collision involving freight train and truck on May 28 2013. The collision occurred at a Stop sign level crossing, and the investigation found that vegetation and a sharp horizontal curve near the crossing limited the truck driver’s ability to see oncoming trains.

Visual perception during curved road approaches

During vision, light energy passes through the eye and is focussed by specialised anatomy onto photoreceptor cells at the back of the eye. The centre of the focussed image falls upon the centre of the retina (the fovea) where there is the greatest concentration of photoreceptors, and particularly cone photoreceptors which are used for detail and colour vision. In combination with head and eye movements which bring objects into the centre of the field of view, this is referred to as visual fixation, and can be colloquially understood of as the process of looking at something.

Visual acuity (the ability to perceive detail) is greatest for objects which are directly fixated upon, and acuity declines as objects become more eccentric to the centre of the fixation point. When objects are more peripheral to the field of view, they will be less likely to be detected, and perceived less accurately with longer reaction times (see Carrasco and others, 1995 for example). Wolfe and colleagues (2019) found that drivers were more likely to detect brake lights of vehicles on the road straight ahead, and were slower and less accurate when detecting brake lights of vehicles which were in more peripheral locations.  

There are no known standards for the visual angle provided for roadside signs and signals.

Research on visual fixations during curved road driving

When navigating straight roads, drivers primarily focus on the straight-ahead position the vehicle will be in the future, with experienced drivers focusing on the visual focus of expansion (which corresponds to the horizon straight ahead) (Underwood, 2007). The visual information about the vehicle’s current and future positions are located within the same field of view, so the driver is not required to look outside their straight-ahead orientation to steer the vehicle.

Scanning behaviour on curved roads is significantly more complex, since a driver must intermittently look towards the vehicle’s current and future positions to steer the vehicle (Transportation Safety Board of Canada, 2015).

Research shows that during driving on curved roads, visual attention is primarily focussed on the 1–2 second headway position of the vehicle, and these ‘guiding fixations’ are thought to provide the driver with just-in-time information to control steering in the curve (Lehtonen and others, 2014).  Due to the geometry of a curve, drivers must look at more obtuse visual angles to observe locations further along the roadway, with such glances described as ‘look ahead’ fixations.

Shinar and others (1977) found that the mean fixation for drivers was straight ahead for right curves, and 3.6° to the left for left curves,[27] with only 5% of the time directed at the opposite side of the road for left curves and 24% for right curves. This was similar to the result found by Cohen and Studach (1977), they showed that when approaching and travelling through a left curve, drivers fixated on the left side of the road and to a lesser extent the middle of the road. Further, when navigating a right curve, drivers fixate on both sides and the middle of the road.

Olsen and others (1989) also examined driver fixation through left and right curved roads during day-time driving (Figure 5). They found that for left curves, the drivers’ fixation was primarily on the left and centre of the road between 100 and 300 ft (30–91 m) in front of the vehicle. With the opposite result (right and centre) for right curves.

Figure 5: Percentage of drivers’ fixation time per road region for left and right curved rural roads during daytime

Researched was conducted in a region where driving is on the right-side of the road. Directions have been reversed for Australian conditions.

Source: ATSB, based on Olson and others (1989). Driver eye fixations under different operating conditions. The University of Michigan Transportation Research Institute.

Lehtonen and others (2014) used eye-tracking methods to measure the distribution of drivers’ visual attention while negotiating a curved road. This research showed that the majority of drivers’ fixations were within 3–4° of the 2-second headway position of the vehicle. Between 65–85% of fixations during curved driving were ‘guiding fixations’ (5° either side of the 2-second headway position), while 2–28% of fixations were ‘look ahead’ fixations (more than 5° either side of the 2-second headway position). The distribution of fixations by angular eccentricity from the 2-second headway position resembled a normal distribution, such that look-ahead fixations with smaller angular eccentricity were much more common than fixations at greater visual angles.

Another study (Lehtonen and others, 2013) showed that while driving along a curved rural road, drivers typically fixated within 6° either side of the future position of the vehicle, although look-ahead fixations (more than 6° of the headway position of the vehicle) were frequent. Between 8–33% of fixations were categorised as look ahead fixations. Under higher cognitive load look-ahead fixations were shorter and directed closer to the position of the vehicle. The average look-ahead fixation was made 8.0 seconds and 112 m prior to the fixation point under lower workload conditions, and 6.9 seconds and 95 m prior under higher workload conditions.

Lehtonen, Lappi and Summala (2012) found that drivers navigating curved roads regularly glanced towards the furthest visible point on a roadway prior to an obstruction (occlusion point). These fixations on the ‘occlusion point’ were interpreted as visual anticipation of potential hazards and the upcoming road alignment. Fixations on this occlusion point were significantly less frequent for right curves²⁷ and in conditions where the driver was under increased cognitive load. Drivers were also less likely to fixate on the occlusion point over consecutive runs, although this effect was not statistically significant.

This research was conducted in Finland (where road vehicles drive on the right side of the road and the driver sits on the left side of the vehicle). Explaining the much lower rates of occlusion point fixation for (Finnish) left curves, Lehtonen and others (2012), suggested:

Notably, each of the 5 level crossing collisions on curved roads identified in the safety study occurred on right curved road (again noting that in Finland vehicle driver on the opposite side of the road). There is no known dataset which describes the number of left and right curved roads approaching level crossings in Australia.

In summary, research has found that while most fixations are focussed on the immediate future position of the vehicle on curves, drivers do engage in scanning of locations further along a curve including at locations which are eccentric in visual angle to the driver. Some of this behaviour is thought to be anticipatory searching along the most distant viewable part of the curve, to identify upcoming hazards.

The degree of the curve, however, may affect the rate at which these anticipatory glances occur. The results reported by Lehtonen and others (2014) indicate that where the occlusion point of the curve required the driver to turn their head to fixate upon it, anticipatory glances were less frequent. This may also have an adverse implication for fixation upon objects as drivers proceed along a curve (and towards an upcoming level crossing), as an object will become more obtuse to a vehicle travelling a curve until the vehicle reaches the maximum turning point.

The observation that anticipatory scanning is reduced under increased workload may have implications for heavy vehicle drivers. Case study examples suggest that driving a heavy vehicle along a curved road requires focussed attention towards vehicle handling, particularly in degraded road conditions such as uneven road surface and worn shoulders[28] or wet roads.

The implication for road vehicle drivers approaching a level crossing along a curved road approach is that they will rely on these anticipatory look-ahead fixations to identify level crossing protection equipment, as this equipment will often not fall within the normal focal point of their guiding fixations. This provides a lower opportunity for drivers to detect level crossings and advanced warning signs compared to when navigating a straight road, when the future position of the vehicle will fall within the guiding fixations. To the extent that look-ahead fixations are constrained by factors such as workload, or do not capture particularly eccentric locations on a curved road, there is an increased likelihood that level crossing protection equipment will not be detected.

It was not possible to determine to what extent roadside and pavement signage warning drivers of the presence of an upcoming level crossing affects the frequency and eccentricity of their look ahead fixations for a level crossing. Drivers may slow their vehicle or engage in more conscious scanning when they encounter such warning signs. This behaviour would reduce the risk of level crossing protection equipment not being detected.

Prior investigations and changes to Australian Standards

In July 2016, the ATSB published an investigation report into a level crossing collision between a road-train truck and a freight train, which occurred on a flashing lights-controlled level crossing with a curved road approach in Narromine, NSW. The report identified that the then-current version of AS 1742.7 (2007 version):

Then, in March 2018, the ATSB published a report into a similar accident at Ivanhoe, NSW. This report identified that AS 1742.7 had been updated to the 2016 revision, including providing consideration to the treatment of crossings with curved road approaches. The ATSB report stated that:

In January 2019, AS 1742.7(2016) was updated. Prior to the revised text amendment, the standard included the following paragraph:

The revised text amendment replaced this paragraph with:

Additional evidence from Standards Australia

In July 2023, the ATSB met with representatives from the Standards Australia technical committee responsible for AS 1742.7: 2016. The committee provided advice about how the standards should be applied in the case of curved road approaches, with observations including:

• The standards are expected to be applied by trained and competent surveyors.
• The inclusion of text stating that level crossing owners may use active advanced warnings is significant, since crossing owners will need to justify why they have not utilised this form of protection equipment.
• The signage and pavement markings required and recommended in the standard would affect the behaviour of road drivers. For example, a road driver who is alerted to the presence of an upcoming crossing may expect and search for a crossing. This means crossing equipment located outside a primary field of view may be detected more readily.

Standards Australia provided additional analysis in September 2023, which stated:

Summary

Research has shown that when driving on a curved road, road vehicle drivers mainly fixate on the immediate headway position of the vehicle and rely on anticipatory look-ahead fixations to observe objects further ahead. This provides less opportunity to detect level crossing protection equipment, compared to driving on a straight road, especially on right curved roads where an advanced warning sign is located not duplicated on the right side.

Standards and guidance for designing and assessing level crossings do not identify the difference in driver sighting behaviour while navigating curved roads. The treatment of curved roads in the standards indicates that road designers and assessors must primarily consider if there is a clear line of sight through a curve. The standards do not convey that while there may be a line of sight through a curve, if this occurs through a large visual angle then there is an increased chance of drivers not sighting the level crossing.

The standards include the provision of active advanced warning on locations along a curved approach road, which would provide a mechanism of locating the crossing warnings within drivers’ central fields of view on curved roads. However, there was no guidance which indicates under what conditions the placement of advanced warning signs is necessary, and the use of these warnings is not mandatory.

This review identified that of 6 collisions which involved a heavy vehicle driver not stopping at a level crossing protected by flashing lights, 5 occurred following a right curved approach road and none of these locations had active advanced flashing light warnings. In 4 of these cases, the assessed available sighting distance was measured from a location where the sighting of the level crossing was from a large visual angle.

The ATSB considers that the absence of procedures or guidance which account for the normal sighting behaviour of drivers on curved roads for determining safety stopping distances and location of advanced warning signs reflects a condition of significant risk.

Safety systems at passive controlled level crossings

Safety system theory and level crossings

This report has described the development of level crossing collisions involving heavy vehicles, including describing the actions of the heavy vehicle drivers which led to the collisions with trains.

The systems safety approach identifies that rather than being the product of individual actions and events, safety is an emergent property of a system. While individual errors and violations affect the development of adverse events, these actions and omissions typically occur in a context where they ‘made sense at the time’. The systemic approach seeks to understand the latent conditions which shaped the behaviour of individual operators and contributed to the conditions at the time of an accident.

The systemic approach also seeks to understand the redundancies available in the system, with the concept of ‘defences-in-depth’ referring to the use of multiple, overlapping risk controls to prevent catastrophic accidents. Administrative controls, such as procedural rules, provide the weakest form of protection against the likelihood and consequence of individual errors by frontline personnel. In contrast, engineering controls provide the greatest level of protection through providing a physical fail-safe barrier which prevents or reduces harm.

The safety system at passive controlled level crossings does not include any engineering controls to alert road vehicle drivers (or pedestrians) about the presence of a train. At passive control crossings, road vehicle drivers must visually search for and detect the presence of a train in order to identify when they can or cannot proceed through a crossing. As such, the design of passive controlled level crossings is primarily dependent on the actions of road vehicle driver to detect both the crossing and detect the presence of trains. If a road vehicle driver does not look for trains, or looks for trains but does not detect that one is approaching, there are limited effective recovery controls to prevent a collision from occurring. The driver may be alerted to the presence of a train by the train horn, however in many instances this is not effective (see Train horn audibility).

With no limited effective recovery controls for instances where the road user does not attend to the crossing or does not detect the presence of a train, the safety system for passive level crossings inherently relies on the road user always attending to upcoming crossings, and always detecting trains.

A human-centred approach to level crossing errors

A large subset of heavy vehicle drivers involved in level crossing collisions were aware that they were approaching or proceeding through a level crossing. The breakdown in safety predominantly occurred due to the drivers not detecting that a train was approaching a crossing. This study identified that of 26 accidents at passively controlled crossings:

• In at least 20 collisions the heavy vehicle driver probably did not detect the presence of the train, or detected the train when it was too late to stop.
• In at least 1 collision the heavy vehicle driver detected the train but incorrectly determined that they could transit the crossing safely.
• In 1 collision the heavy vehicle driver detected the train but records indicated the truck had defective brakes and could not stop.
• In 4 collisions there was not sufficient evidence to determine whether the heavy vehicle driver had detected the presence of a train.

Overall, in a large majority of the 26 collisions at passive controlled level crossings, the heavy vehicle driver unintentionally proceeded into the crossing without detecting the presence of the train. These collisions reflected unintentional slips and lapses, where the drivers unintentionally deviated from the intended course of action (to give way to trains).

Reason (1990) notes that such errors typically occur in the context of a routine, well-practiced task where behaviour is largely automatic. Attention is captured by a distraction or other demand, and the operator misses the cues to depart from the ‘normal’ routine.

Applying this conceptual framework to level crossing collisions, driver errors take place in the context of the highly-practiced task of road vehicle driving, in roadway environments where other demands and distractions are often prevalent. Road vehicle driving can become highly automatic, and many road vehicle drivers will recall the experience of arriving at a common destination without a recollection of the journey. The phenomenon of ‘highway hypnosis’ or ‘driving without attention mode’ describes the degradation of vigilance towards the roadway associated with factors including monotonous driving conditions (Karrer and colleagues, 2005). In the context of a potential level crossing collision, drivers are required to depart from the current (and often automatic) schema of continuing to drive the motor vehicle along the road, and adopt a schema of looking and preparing to stop for trains.

The task of approaching a passive control level crossing is thus consistent with the conditions described by Reason (1990) as being conducive to the development of errors involving inattention. Road vehicle drivers are vulnerable to becoming ‘captured’ by focus on other aspects of road vehicle driving, and not attend to the roadside or the rail track to detect level crossings and trains.

As described in Factors affecting heavy vehicle driver behaviour at level crossings above, there are various factors which may contribute to road vehicle drivers not looking for, or detecting the presence of, a train at a passive control level crossing. As highlighted by Edquist and others (2009), when considering the perceptual and cognitive factors inherent in the task of approaching a passive control level crossing:

This is consistent with analysis by the Transportation Safety Board of Canada[29] (TSB), which found that:

The US National Transportation Safety Board (NTSB) safety study of collisions at passive control level crossings[30] made a similar conclusion, arguing that the long-term objective to reducing collisions at level crossings should be to eliminate passive control crossings.

In summary, many of the collisions and near misses identified in this study speak to the inherent variability of human performance, in the context of a system which is conducive to unintentional errors. Level crossing safety may be improved by the introduction of other risk controls to reduce the frequency of level crossing collisions or reduce their consequences.

Potential safety improvements for passive control crossings: the case for in-vehicle warning systems

Background

One proposed method for improving the safety of passive level crossings is using in-vehicle alerting technology to alert road vehicle drivers of a requirement to stop and give way to an approaching train. Such applications would reduce the safety system’s reliance on the driver to search for and detect the presence of a train, by attracting the driver’s attention and thereby providing a salient cue to the driver to stop.

In-vehicle alerting systems for level crossings have been proposed by previous investigations and reviews of level crossing collisions. Following a review of collisions at passive control level crossings, the NTSB (1998) noted:

Reporting on an accident at a passive control level crossing, the Canadian TSB found:

In the Australian context, a 2009 Parliamentary committee Level crossing safety recommended that:

Then, in 2013, the Coronial inquest into multiple fatal level crossing collisions (including the collision at Kerang, Victoria) recommended rail operators, infrastructure managers and regulators:

In summary, there is broad agreement among informed stakeholders both within Australia and internationally on the inherent challenges of relying on road users to attend to and detect the presence of trains at passive control crossings. Multiple stakeholders have endorsed the development of in-vehicle alerting technology for level crossings to improve the safety at passive control level crossings.

Current maturity of in-vehicle level crossing warning systems

The ATSB sought information about the development and trial of level crossing alerting technology following the recommendations made in the Coroners Court of Victoria’s Coronial Investigation of Twenty-six Rail Crossing Deaths in Victoria, Australia (2013). The Victorian Government Department of Transport and Planning advised that trials had been conducted, however the technologies were found to be unreliable. The Department further advised that the development of technology was being monitored, with a 5- to 10-year timeframe expected for a viable technology. Trials of level crossing technology cited by the Department included:

• In 2013, the La Trobe University Centre for Technology Infusion reported on the development and evaluation of 5.9 GHz Dedicated Short Range Communication (DSRC) system which provided audio and visual alerts to road users approaching a crossing. Field trials were conducted in rural and urban locations, involving 124 participants over 4.5 months. The trials included variants where trains and vehicles communicated directly, and variants where the vehicles communicated through a roadside unit intermediary.
  The results of the field trials showed that connectivity between vehicles was dependent on there being a clear line of sight between receiving units, and that the system provided much less connectivity range when no roadside unit was deployed.
• The Collaborative Research Centre for Rail Innovation (2014) reported on a separate trial of the La Trobe University DRSC system. This report noted that ‘drivers experienced a high number of hardware issues with the Latrobe system: display falling off, warning messages when no train was approaching. Further, participants had to start the system manually every time they started driving, which was found annoying. All of this resulted in a low usage of the system during the trial’.

A review of international research into level crossing warning systems identified the US Federal Railroad Administration Rail-Crossing Violation Warning (RCVW) project (Withers and Utterback, 2021). This RCVW detects the status of active control level crossings. This system would produce in-vehicle messages for all vehicles approaching an active crossing of the requirement to stop (inform message), and an alert if the vehicle is not predicted to stop based on its speed (warning message). Field testing has shown that system provided a reliable warning system for active control level crossings, using currently available technology. Notably, this technology does not detect whether a train is approaching the crossing (relying on existing active crossing equipment), and thus does not provide a solution for passive controlled crossings.

In summary, there is no known research which has demonstrated a proof-of-concept for a system for providing alerts to road vehicle users when approaching level crossings. Research conducted at Australian level crossings indicated that the available technology was not reliable. Given this research is a decade old, additional research is now required to determine whether technological advancement will now provide a useable platform for providing warnings to drivers approaching level crossings.

Human factors considerations for in-vehicle level crossing warning systems

In addition to the absence of mature technology for providing in-vehicle level crossing warnings, there are potentially significant implications for how such warnings would affect the behaviour of road vehicle drivers at level crossings. The phenomenon of behavioural adaptation has been observed in response to other changes to the road traffic system, where there is an observed aggregate change in the behaviour of road users following system changes, often resulting in the estimated benefits of the changes to be under-achieved. For example, research has identified that drivers presented with adaptive cruise control attended more frequently to a secondary task and had lower reaction times (Rudin-Brown and Parker, 2004). Similar results have also been observed in studies of adaptation to forward collision warning systems (Reinmueller and others, 2010).  

In the case of in-vehicle level crossing warnings, it is possible that road vehicle drivers may adapt to the presence of the warnings, and that this may affect their attention to traditional level crossing control equipment (Wullems and others, 2014).

Simulator research showed that participants who drove a vehicle equipped with an in-vehicle alerting system were less likely to comply with level crossing rules when there were no trains present. Drivers also approached the crossings at faster speeds and glanced less frequently at the rail track (Larue and others 2015). These changes were only observed when the driver was presented with a visual warning, and driving behaviour improved when an aural warning was presented.

As identified by Wullems and others (2014), the potential for over-reliance on in-vehicle warnings and changes to driving behaviour at level crossings presents potential hazards, unless the systems are perfectly reliable. Any failure of the system would produce a potentially very hazardous system state, particularly if the road user does not identify the failure.

It may also be hazardous to incrementally introduce the equipment necessary to provide in-vehicle warnings. If road vehicle drivers were to come to expect in-vehicle warnings for potential level crossing collisions, then level crossings and/or trains which were not equipped with the equipment required to produce these warnings would potentially become less safe than they are currently.

Other barriers to the implementation of in-vehicle level crossing warning systems

Any foreseeable system for providing in-vehicle level crossing warnings requires road vehicles be equipped with devices for receiving and displaying warnings, and the potential benefit of any warning system would depend on the installation uptake of such equipment. Considering the size of the road vehicle fleet (over 20 million road vehicles were registered in Australia in 2022), this could be a complex and costly exercise, requiring the co-ordination of stakeholders outside the rail industry. However, with advancements in navigation systems in many on-road vehicles today that allow for software updates, this is likely to be less complex in the future.

A final barrier to the implementation of in-vehicle level crossing warning systems relates to the ownership of risk at level crossings, and how responsibility for in-vehicle warnings could be managed. The existing regime for level crossing safety includes shared responsibility between rail and road infrastructure managers (as reflected in level crossing interface agreements), and with railway operators and road vehicle drivers for complying with relevant rules and procedures. Wullems and others (2014) identified that the introduction of in-vehicle level crossing warning systems would pose unresolved questions relating to where responsibility lies for ensuring that warnings are produced by rail vehicles and/or infrastructure, and being received by road vehicles. The ongoing monitoring, management and maintenance of such a system may require significant cost for rail industry organisations.

Wullems and others (2014) further identified that failures in the system which led to collision may produce a liability for rail operators or infrastructure managers, whereas in the existing regime these stakeholders can discharge their responsibility by providing compliant level crossing infrastructure and operating rollingstock correctly.

Whereas the use of in-vehicle warnings has been mooted as a low-cost method for improving safety at passive control crossings, there are significant changes required to implement such technology which may involve significant cost. The size of these costs is unknown, and will need to be more precisely understood to evaluate the safety case of potential alerting technologies, should fit-for-purpose technologies emerge.

Discussion

Study limitations

This study reviewed level crossing collisions involving heavy road vehicles, to understand their characteristics and trends, and in turn to identify risk factors and opportunities for safety action. This study did not review the characteristics and trends of heavy vehicle movements across level crossings which did not result in a collision. This limited the inferential capability of the study, such that it was not possible to quantify how specific characteristics of the vehicles, crossings, or other variables identified in the study contributed to the development of collisions.

Similarly, the study did not conduct an in-depth review of the characteristics and trends of level crossing collisions involving other road vehicles. As such, it was not possible to quantify how the different characteristics of heavy vehicles, or the different road and crossing conditions they may be exposed to, contributed to the observed differences in collision frequency and consequence. A richer dataset for all level crossing collisions would support such analysis.

Another limiting feature of this study was that the information used to understand the characteristics of level crossing collisions involving heavy vehicles was primarily drawn from investigation reports produced by rollingstock and infrastructure managers, and from police reports. These reports were produced in the context of the operator and infrastructure managers’ specific interests and/or legal requirements, and not with a view to support broader analysis such as this.

The data used in this study was obtained from sources that included either live databases where the data can be updated through additional data gathering or data cleaning exercises. For one level crossing accident reviewed in this study, the source material included an Office of the Chief Investigator investigation that was ongoing at the time the study was published.

The ATSB did not conduct any site inspections or audits against relevant standards of the level crossings involved in the occurrences in this safety study. Previous ATSB investigations of level crossing collisions have included site inspections and other analyses of the crossings, and the safety study utilised records from these observations. Otherwise, the safety study relied on observations of level faults or deficiencies recorded in rail infrastructure manager reports and other documents.

Information about the factors which affected the performance of heavy vehicle drivers was infrequently reported in operator and police reports. In most instances, these reports only identified that the road vehicle driver failed to give way, and these records rarely assessed human factors causes which could explain the drivers' errors.  

In contrast with operator and police reports, investigations conducted by the ATSB seek to understand the operation of the overall safety system, and to identify opportunities to improve that system. The objective is not to attribute blame or liability. The ATSB also has strict limitations on how information collected from involved parties can be used outside of the no-blame investigation process, which probably increases the likelihood of obtaining evidence such as statements from heavy vehicle drivers.

The independent no-blame investigations conducted by the ATSB were much more likely to provide sufficient information to describe the actions of the heavy vehicle drivers, and to provide information which explained these actions. As shown in Table 17, the proportion of collisions where the ATSB was unable to code key details about the heavy vehicle driver’s actions or the factors associated with those actions was much greater for collisions not investigated by the ATSB.

Table 17: Counts of collisions where road vehicle driver actions and related variables could not be coded due to missing information

There are some important caveats in drawing conclusions based on these differences. Most importantly, the collisions not investigated by the ATSB were different events, and may not have involved the factors identified in the collisions investigated by the ATSB. Also, the ATSB typically allocates more time and resources to conducting an investigation than a rail organisation would, and it is difficult to distinguish the effects of this resourcing with the benefits of conducting no-blame investigations.

Nonetheless, the ATSB considered that the information obtained in this study demonstrated that meaningful understanding of why heavy vehicle drivers enter level crossings contrary to the road rules was typically only available following an independent no-blame investigation. As these actions represent the fundamental breakdown of safety at level crossings, this supports the benefit of regularly investigating significant collisions at level crossings.

Overall observations as to heavy vehicle level crossing risk

The information reviewed in this safety study indicated that heavy vehicles pose a greater risk at level crossings than light vehicles, as a function of greater accident consequence for rail users. The collisions involving heavy vehicles resulting in more significant consequences was consistent with the observations of previous research, and can be easily understood as a simple reflection of the increase in physical forces imparted on a rail vehicle as the mass of the road vehicle involved in a collision increases (for a fixed speed).

Also consistent with previous analyses, this study identified that heavy vehicles are more likely to be involved in level crossing collisions, compared to light vehicles, per road distance travelled. The increase in level crossing collision frequency for heavy vehicles may be partially explained by a greater exposure to level crossings, and in particular greater exposure to level crossings with lower levels of protection (especially in rural areas). The study was unable to test the extent to which different exposure to level crossing hazards explained the difference in collision rates.

Nonetheless, the over-representation of heavy vehicles in level crossing collisions is likely to be due, in some part, to the fundamental physical property of heavy vehicles: that they are larger and take longer to stop prior to a crossing, and clear a crossing, as a function of both time and distance. Although the design of level crossings seeks to accommodate the stopping limitations of heavy vehicles (see Appendix B), it is inevitable that a heavier vehicle will be less likely to stop within a specific distance and time, all other factors being equal. Stated alternatively, all safety improvements at level crossings seek to increase the margins available for a road vehicle to stop and give way to trains, and any improvements which increase the ability of heavy vehicles to stop at level crossings will have a greater benefit to smaller vehicles whose braking capabilities are generally greater. As such, it is likely that heavy vehicles will continue to be over-represented in level crossing collisions.

The characteristics of heavy vehicle driving may also represent systemic risk factors which partially account for the over-representation of heavy vehicles in level crossing collisions. Plausible mechanisms for such systemic effects include:

• The handling characteristics of heavy vehicles may contribute to a greater tendency of heavy vehicle drivers to engage in ‘rolling-stop’ violations at level crossings, compared to the drivers of other road vehicles.
• The louder operating noises produced by heavy vehicle engines and heavier cab construction may result in heavy vehicle drivers being less likely to hear train horns, compared to the occupants of other road vehicles.
• The construction of heavy vehicle cabs may also provide more visual obstructions, making it more difficult for heavy vehicle drivers to detect trains and level crossing equipment.
• The nature of heavy vehicle driving is often one of repeated journeys along the same route. This familiarity can contribute to the expectancy that level crossings along the route will not be occupied by trains.

As identified in Study limitations, this study did not include data from heavy vehicle movements across level crossings that did not result in a level crossing collision, and did not conduct a thorough review of collisions involving non-heavy road vehicles. Due to this, it was not possible to accurately determine the characteristics of heavy vehicles that contributed to the greater frequency of level crossing collisions (per road distance travelled).

Overall observations as to level crossing collision characteristics

Of the 49 level crossing collisions involving heavy vehicles, at least 7 were partially attributable to problems with the design or maintenance of the level crossings. Generally, however, the collisions reviewed in this study occurred at level crossings designed according to the required standards. Also, there were no collisions attributed to the crossing providing insufficient sighting for a stopped heavy vehicle to start up and clear the crossing prior to a train arriving.

However, the study identified one systemic problem with the design criteria for level crossings. The methods used to calculate safe stopping distances for road approaches to level crossings did not account for the effect on sighting a level crossing from the normal focal points of drivers negotiating a curved road. While this problem did not only relate to heavy vehicles for the design of level crossings, heavy vehicle drivers are likely to be particularly affected in situations where insufficient sighting distance is provided.

The majority of level crossing collisions arose from heavy vehicle drivers entering the level crossings following some form of unintentional error or omission. Even in the case where heavy vehicle drivers deliberately engaged in actions contrary to the road rules, the intention was to proceed through the crossing prior to the arrival of a train. The collisions were primarily caused by level crossing warnings or the presence of trains not being detected, being detected late, or being perceived incorrectly. This form of omission or misperception can also affect other road users, and the forms and causes of errors observed in heavy vehicle drivers were consistent with the errors made by the drivers of other road vehicles, both at level crossings and in other areas of the road network.

As described in A human-centred approach to level crossing errors, many of the errors and omissions which lead to level crossing accidents reflect the inherent variability of human performance. While the level crossing safety system continues to heavily rely on road vehicle drivers adhering to the administrative controls of road rules and other procedures to prevent collisions between vehicles and trains, it is a certainty that from time to time, this will not occur and so collisions will continue to occur. However, the use of engineering controls which alert road users to a requirement to stop will almost certainly provide an enhanced level of safety at level crossings, by reducing the reliance on road users to attend to and detect the presence of trains.

Findings

From the evidence available, the following findings are made with respect to the review of level crossing collisions between trains and heavy road vehicles.

Factors that increased risk

• Of the 49 level crossing collisions involving heavy vehicles, at least 7 partially involved problems with the design or maintenance of the level crossings. Concerning compliance with applicable design standards, no significant issues were identified with the design or maintenance of most crossings.
• Level crossing collisions between trains and heavy vehicles were associated with greater levels of rail injuries and rail damage than collisions involving light vehicles.
• Heavy vehicles are involved in level crossing accidents at a greater rate per road kilometre travelled than light vehicles.
• Although level crossing collisions between heavy vehicles and trains were more likely to involve the train striking the heavy vehicle, accidents where the heavy vehicle struck the train were more likely to cause a derailment.
• All level crossing collisions involving heavy vehicles resulted from the heavy vehicle driver not giving way to trains. There were three actions associated with the collisions:
  • There were at least 24 accidents where the heavy vehicle did not stop prior to entering the crossing.
  • There were at least 11 accidents where the heavy vehicle stopped at the crossing then proceeded into the path of a train.
  • There were at least 13 accidents where the heavy vehicle entered a level crossing and stopped foul of the train line.
• In at least 14 collisions it is likely that the heavy vehicle driver intentionally entered the level crossing in a manner which was contrary to road rules. These included 6 collisions where the driver intentionally entered the crossing without being able to drive clear of the crossing, 4 collisions where the driver engaged in a 'rolling stop' while approaching a Stop sign level crossing, 3 collisions where the driver remained stopped foul of the crossing while there was no obstacle preventing them from exiting, and one collision where the driver did not stop or look for trains at a Stop sign crossing.
• Of 26 collisions at passive control crossings, there were at least 12 accidents where the heavy vehicle driver slowed or stopped but probably did not detect the train, and entered the crossing into the path of the approaching train.
• There were at least 12 level crossing collisions where the driver of the heavy vehicle had regularly used the level crossing prior to the collision with a train. This included 6 accidents where the heavy vehicle driver proceeded into a passive control crossing without identifying the presence of a train, and 5 accidents where the heavy vehicle driver did not identify activated flashing level crossing lights. The drivers' previous experience at the level crossings likely led to a low expectancy for trains and, in at least some collisions, contributed to them not detecting a requirement to stop and give way.
• Of the 49 level crossing collisions involving heavy vehicles, there were at least 14 collisions where the heavy vehicle driver’s view was obstructed by vegetation, the design of the heavy vehicle cab, poor crossing lighting, or sun glare.
• Previous research and reviews have identified that train horns have limited effectiveness for alerting road vehicle drivers to the presence of trains. Consistent with this, in at least 25 collisions, the horn was not effective at alerting the heavy vehicle driver to the presence of the train.
• The methods used in the Australian Standard AS 1742.7:2016 to calculate safe stopping distances, and determine the need and location of advanced warning signs for road approaches to level crossings, did not account for the likelihood of detecting the level crossing ahead based on the normal visual focal points of road drivers negotiating a curved road. While the standards included guidance for the use of active warning signs for curved road approaches to flashing light controlled crossings, this was not mandatory. There were 6 collisions in which driver of a heavy vehicle did not detect that level crossing flashing light signals were activated until it was too late to stop. In 5 of these collisions, the drivers approached the crossing along a right curved approach road and none of these crossings had active advance flashing light signals (Safety issue).
• Of 26 collisions at passive control level crossings, a large majority involved the heavy vehicle driver not detecting the presence of the train. These crossings rely on the road vehicle driver detecting the presence of a train and identifying a requirement to stop and give way, and are susceptible to situations where motorists do not look for, or detect, the presence of a train. There are limited effective recovery controls to prevent a collision when this occurs.

Other findings

• Information which supports an understanding of the factors associated with heavy vehicle drivers entering a level crossing without giving way to trains is typically only available when an independent no-blame transport safety investigation is conducted.
• The annual number of level crossing collisions between road vehicles and trains remained relatively constant between July 2014 and June 2022.
• Prior to July 2022, the national rail safety database did not include sufficient information to enable detailed analysis of level crossing collision characteristics.

Safety issues and actions

Standards and guidance for placement of crossing equipment on curved road approaches

Safety issue number: RS-2021-001-SI-01

Safety issue description: The methods used in the Australian Standard AS 1742.7:2016 to calculate safe stopping distances, and determine the need and location of advanced warning signs for road approaches to level crossings, did not account for the likelihood of detecting the level crossing ahead based on the normal visual focal points of road drivers negotiating a curved road. While the standards included guidance for the use of active warning signs for curved road approaches to flashing light controlled crossings, this was not mandatory. There were 6 collisions in which driver of a heavy vehicle did not detect that level crossing flashing light signals were activated until it was too late to stop. In 5 of these collisions, the drivers approached the crossing along a right curved approach road and none of these crossings had active advance flashing light signals.

Sources and submissions

Sources of information

The sources of information during the investigation included the:

• Office of the National Rail Safety Regulator
• Rail operators
• Rail infrastructure managers
• Australian Level Crossing Assessment Model Committee
• Federal Railroad Administration
• Rail Industry Safety and Standards Board
• New South Wales Police
• South Australia Police
• Victoria Police
• Queensland Police Service
• National Heavy Vehicle Regulator

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Submissions

Under section 26 of the Transport Safety Investigation Act 2003, the ATSB may provide a draft report, on a confidential basis, to any person whom the ATSB considers appropriate. That section allows a person receiving a draft report to make submissions to the ATSB about the draft report.

A draft of this report was provided to the following directly involved parties:

• Office of the National Rail Safety Regulator
• Australian Standards technical committee MS-012
• Australian Level Crossing Assessment Model committee
• National Heavy Vehicle Regulator
• Austroads
• Rail Industry Safety and Standards Board

Submissions were received from:

• Office of the National Rail Safety Regulator
• Australian Level Crossing Assessment Model committee
• Austroads
• Rail Industry Safety and Standards Board

The submissions were reviewed and, where considered appropriate, the text of the report was amended accordingly.

Glossary

Appendices

Appendix A – Descriptive statistics for level crossing collisions recorded in National rail safety database

Collisions

Appendix B – Summary of sighting distance provisions in Australian Standard AS1742.7:2016

The design criteria for level crossings in Australia are specified the Australian Standard AS 1742.7:2016, Manual of uniform traffic control devices. Part 7: Railway crossings. This standard prescribes the sighting distances required for drivers approaching a level crossing, to enable them to safely identify if it is safe to enter and proceed through a crossing.

The standard seeks to ensure that the driver of a design vehicle will have sufficient time and distance to identify a crossing ahead (S₁) and stop after identifying a requirement to stop. In the case of active control crossings, this would be the detection of flashing lights and/or a lowered boom gate, whereas in the case of a Stop sign controlled crossing, this would be the presence of the Stop sign.

The standard also specifies the minimum distance for a driver to approach the crossing, look along the rail line to check for trains, and then continue and cross safely ahead of any undetected trains (S₂). This is applicable in the case of Give way controlled crossings, where the driver is not required to stop unless a train is detected.

For vehicles stopped at a level crossing, the standard specifies the distance required to be visible along the track from the ‘stop line’. The distance (S₃) is required to be sufficient for the vehicle to start up and clear the crossing prior to the arrival of any train beyond the visible distance.

These distances are illustrated in Figure 6.

Figure 6: Illustration of level crossing sighting distances specified by AS 1742.7:2016

These are expressed in the standards as

These formulae contain variables relevant to the physical characteristics of heavy vehicles. Specifically:

In the case of heavy vehicles, AS 1742.7 specifies values for design vehicles for defined categories of heavy vehicles, with greater vehicle length, slower braking and acceleration, and longer reaction times expected for heavier vehicles.[31] The effect of this is that for crossings expected to carry heavy vehicles, AS 1742.7 requires longer sighting distances are provided.

The ATSB modelled the distances required by AS 1742.7 using a standard case of a crossing on a flat, sealed road, where the road speed was 100 km/h,[32] the track speed was 110 km/h and the road to track angle was 90°. The calculated stopping distances for different types of heavy vehicles are shown in Table 18.

Table 18: AS1742.7 calculated stopping distances for heavy vehicle types

Purpose of safety investigations The objective of a safety investigation is to enhance transport safety. This is done through: identifying safety issues and facilitating safety action to address those issues providing information about occurrences and their associated safety factors to facilitate learning within the transport industry. It is not a function of the ATSB to apportion blame or provide a means for determining liability. At the same time, an investigation report must include factual material of sufficient weight to support the analysis and findings. At all times the ATSB endeavours to balance the use of material that could imply adverse comment with the need to properly explain what happened, and why, in a fair and unbiased manner. The ATSB does not investigate for the purpose of taking administrative, regulatory or criminal action. Terminology An explanation of terminology used in ATSB investigation reports is available here. This includes terms such as occurrence, contributing factor, other factor that increased risk, and safety issue. Publishing information Released in accordance with section 25 of the Transport Safety Investigation Act 2003 Published by: Australian Transport Safety Bureau © Commonwealth of Australia 2024 Ownership of intellectual property rights in this publication Unless otherwise noted, copyright (and any other intellectual property rights, if any) in this report publication is owned by the Commonwealth of Australia. Creative Commons licence With the exception of the Coat of Arms, ATSB logo, and photos and graphics in which a third party holds copyright, this publication is licensed under a Creative Commons Attribution 3.0 Australia licence. Creative Commons Attribution 3.0 Australia Licence is a standard form licence agreement that allows you to copy, distribute, transmit and adapt this publication provided that you attribute the work. The ATSB’s preference is that you attribute this publication (and any material sourced from it) using the following wording: Source: Australian Transport Safety Bureau Copyright in material obtained from other agencies, private individuals or organisations, belongs to those agencies, individuals or organisations. Where you wish to use their material, you will need to contact them directly.

Executive summary

What happened

In August 2021, during the COVID-19 pandemic, Formosabulk Clement diverted to Brisbane, Queensland for crew change, to be completed to/from a launch via the combination pilot ladder. At the time, Queensland was the easiest jurisdiction in Australia for ships to conduct crew change due to the State’s extensive quarantine arrangements for transporting and accommodating seafarers. By 1833 on 9 August, 8 persons and their luggage had been successfully transferred from the launch PT Transporter to the ship located at an outer anchorage. The launch skipper then drove the launch a short distance off the ship for a short break.

By this time, the ship had turned about the anchor and the boarding side of the ship came under the influence of the forces of wind and sea. After receiving supervisor advice to attempt the transfer again, the launch skipper took the launch back toward the boarding area to assess whether the conditions were suitable. On board Formosabulk Clement, the departing chief mate (dCM) saw the approaching launch and went down the access ladders and onto the vertical pilot ladder in anticipation of boarding. At about 1838, as the dCM waited on the ladder and the launch came close alongside, a large wave passed down the side of the ship and lifted the launch higher than expected. The dCM was struck by the launch and knocked into the sea. Despite being quickly recovered on board, they received fatal injuries.

What the ATSB found

The investigation found that the open water conditions at the anchorage were marginal but, within a lee created by the ship, they were suitable for the transfer to occur. However, as the skipper brought the launch alongside to assess conditions, the transfer area was no longer in a lee and waves were acting against the ship’s side, increasing in height as they passed along it.

Coincident breakdowns in communications between, and within, the ship and the launch resulted in the ship’s master, the dCM, the launch skipper and the launch deckhand having different understandings of the significance and intent of the launch returning alongside the ship.

In addition, the dCM went down the boarding ladders in preparation to board the launch without the knowledge or agreement of either the ship’s master or the launch skipper. The dCM was then in a vulnerable position when the launch was lifted on the higher than expected wave.

The investigation also found that plans and details of how the transfer was to be controlled and progress when the launch was alongside were not adequately shared between all parties in the time available as the launch approached the ship. Neither the shipping company nor the launch company had in place procedures to ensure that such information was shared before the ship arrived at the anchorage.

As a consequence, different interpretations and misunderstandings of the plan and expectations of the people involved in the transfer, particularly those in positions of influence over the progress of the transfer, were not identified and addressed.

What has been done as a result

Following the accident:

• the launch service provider (Pacific Tug) ceased crew transfer operations until an investigation into the accident and assessment of transfer operations were completed
• Maritime Safety Queensland (the State’s regulator) amended the COVID crew change procedure for vessels at anchor including limiting crew changes to risk assessed conditions and daylight hours only
• Formosabulk Clement’s operator, Formosa Plastics Marine Corporation, completed investigations and held multiple safety meetings and training exercises to share details of, and lessons learned from, the accident.

Subsequently, Pacific Tug updated personnel transfer arrangements and procedures. This included developing and implementing a traffic light system (red, amber and green statuses) for operational assessment and control. The system set operational requirements and limits, including weather, against which the conduct of the transfer task was continually assessed. Light sets, mounted on the launch, are used to show the status of the transfer to all involved, on the launch and the ship. A red status requires cessation of the transfer operation and complete reassessment prior to any further attempt to complete the task.

Safety message

All parties are reminded of the importance of maintaining active and adaptable communications before and during the planning, co-ordination and control of a complicated task.

Further, where possible, all parties should share plans and information well before undertaking a task so as to allow all involved to have a common and complete understanding of the planned activity.

The occurrence

During the COVID-19 pandemic, the international maritime industry struggled to comply with requirements for the maximum continuous period that a seafarer could serve on board a ship without taking leave.[1] Following a period of grace during which the continuous service period was relaxed to 14 months, in November 2020, the Australian Maritime Safety Authority (AMSA) notified ship owners, operators and seafarers that it would resume enforcing the 11‑month continuous service limitation from 28 February 2021.