The signal passed at danger (SPAD) alarm for CS025 did not alert the network control officer when train TE43 passed the signal at stop. This was due to inherent constraints of the universal traffic control system, which was not considered in the way Queensland Rail managed the risk of SPADs.
Response by Queensland Rail
On 11 April 2025, Queensland Rail (QR) acknowledged that there were known circumstances in which Universal Traffic Control (UTC) may not generate a SPAD alarm at all signal locations on the QR Network.
QR identified that there were approximately 241 signal locations, approximately 5% of coloured light automatic signals throughout the network where SPAD detection, via a UTC system alarm, may not always trigger following a SPAD occurrence. Additionally, in the last 4 years, there have been 3 occasions of a SPAD at an automatic signal, of which all were self‑reported from the driver to the network control officer (NCO) in accordance with their training. QR noted that this training ensured that alternative risk minimisation controls were available and suitable beyond automated alarms so far as is reasonably practicable (SFAIRP).
QR further noted that the NCO’s intervention following a SPAD was operationally critical, however it advised that it did not meet the threshold of a critical risk control under its risk management framework. It stated that the current risk assessments supported the organisation’s SFAIRP risk management position for SPAD management.
In response to the safety issue, QR provided the ATSB with a list of safety actions from the SPAD Prevention Taskforce that was established in 2017.
It advised that the following safety controls and initiatives had been implemented which focused on:
Infrastructure improvements initiatives to improve train handling:
QR noted that while these actions represent a reasonable approach to SPAD management, QR along with the other participants in the rail industry, continue to face challenges in fully addressing the limitations of legacy systems, such as AWS, in preventing SPADs. The development and implementation of more advanced automatic safety systems such as European Train Control System (ETCS) remains a strongly preferred option for further improving rail safety and long-term interoperability.
Additionally, QR provided an extract of the risk register reviewed on 22 September 2021 conducted by the Discipline Head Rollingstock. This included a SFAIRP justification that introduction of ETCS would reduce the risk score when implemented. It also listed ‘Application of UTC’ as a substantially effective risk control. QR noted that the assessment included risk controls that were both partially and substantially effective, and they identified the risk of a SPAD incident at the enterprise level as Medium.
On 11 January 2024, Queensland Rail conducted a comprehensive review of its SPAD Risk Management framework against relevant Australian Standard AS 7457:2019 Management of SPADS and Proceed Authority Exceeded to inform a review and update of MD‑10‑89 SPAD Risk Management Standard. MD‑10‑89 was updated on 23 August 2024.
ATSB comment
Queensland Rail identified that there were several locations on the SEQ network where an alarm may not be generated following a SPAD. While the locations were generally associated with an automatic signal, there were situations where an alarm would also not generate at the next signal (automatic or controlled) if the replacement track of the following signal was already occupied. The ATSB notes that in this instance a driver would have passed 2 signals at stop. In these situations, the emergency response was reliant on the driver self‑reporting the SPAD to the network control officer (NCO).
The self‑reporting of a SPAD by the driver is not effective in scenarios where the driver does not recognise that they have passed a signal at stop (that is, the driver completely missing the limit of authority), and consequently does not self‑report the SPAD. Previous investigations conducted by the ATSB (RO‑2018‑002, RO‑2017‑010) found in both instances the driver exceeded their limit of their authority without realising and, following the display of an alarm, the NCO actively intervened to stop the train, mitigating risk to train operations.
The ATSB considers the scenario where a SPAD alarm is not generated, and the driver does not report the SPAD, had not been considered in the Queensland Rail risk assessments.
Queensland Rail provided extracts from its risk registers to manage SPAD events dated in 2021. These registers had not been updated since the occurrence and did not assess inherent universal traffic control system conditions that may lead to risk controls being ineffective.
The Australian Transport Safety Bureau recommends that Queensland Rail reviews the risk associated with a signal passed at danger (SPAD) in circumstances where the inherent constraints of the universal traffic control system do not alert the network control officer and the driver does not self‑report, and any additional risk controls that may be appropriate for the current signalling system.
