Signals passed at danger (SPAD)
A signal passed at danger (SPAD) is an occurrence where a train passes a signal displaying a stop indication without the authority to do so.
Only a small percentage of SPADs result in a serious accident but they provide warnings about failures or deficiencies in safety risk controls.
Investigating SPADs can help the rail industry to better manage risk and improve overall safety management by identifying the human factors that lead to occurrences.
Resources available to assist operators include investigation tools, an information paper and bulletin on SPADs.
SPAD investigation process
Rail infrastructure managers and rolling stock operators can investigate SPADs using a systematic approach as presented in the flow chart below.

Investigation tools
- Initial SPAD data collection tool for rail infrastructure managers – tool A
- SPAD data collection tool for rolling stock operators – tool B
- Mitigation measures for tool B – rolling stock operators
- SPAD data collection tool for rail infrastructure managers – tool C
- Mitigation measures for tool C – rail infrastructure managers
Related documents
Guidance
Transport safety bulletin
Alerts and news
- ITSR releases signals passed at danger data
- Information alert - OTSI rail investigation - Signal passed at danger by track machine consist 8M71 at Goobang Junction on 10 May 2009





