RIS-3119-TOM Iss 3

Accident and Incident Investigation


This document sets out requirements and guidance for the investigation of adverse events involving more than one duty holder so that system improvements necessary to prevent or reduce the likelihood of recurrence, or mitigate the consequences, are identified and implemented.

Summary Of Changes

The Rail Industry Standard has been revised at Appendix H7 to align with the new sub-categories available in the Safety Management Intelligence System (SMIS) for recording Human Performance and 10 Incident Factors, enabling more detailed classification of causes.

Appendix P has been revised to provide additional guidance and clarity on levels of signal passed at danger (SPAD) investigations and who is the lead investigator.

Appendix K has been revised to clarify the structure and content of investigation reports, specifically the ‘factors for consideration’ section.

Amendments have been made to guidance to encourage industry to collaborate on one joint investigation.

Minor amendments have been made to improve clarity and consistency, with references to documentation or legislation updated.

The changes will support higher quality investigations. More focused classification of causes will improve trend information, assisting industry learning, and reducing incidents. The financial benefit is expected to be around £340,000 over five years.

Optional reading and resources:

SPAD Investigation Report Template

Watch our webinar for more information

Accident Investigation and Learning

Accident Investigation Resource

Training - Accident Investigation Awareness for Managers


Read full standard
Rail Industry Standard
Next Review:


Under Consultation Closed
Vehicle Assessment No
Supersedes RIS-3119-TOM Iss 2.2
Lead Committee Traffic Operation and Management - TOM
Briefing Notes 22 BN04
Impact Assessments
22 IA01