We bring a balanced approach to the investigation process, explaining what happened, and why, in a fair, unbiased and constructive way.
Initiating an OTSI investigation
The Transport Administration Act 1988 empowers the Chief Investigator to conduct investigations into rail and passenger transport accidents under the Passenger Transport Act 1990.
The Chief Investigator can investigate any transport accident or incident that may affect the safe provision of railway operations or public passenger services on buses or ferries.
The NSW Minister for Transport can request that the Chief Investigator investigate and advise the Minister about any matter related to the safe operation of transport services.
Transport operators are required to report certain incidents and accidents to the regulators and other authorities. These are usually referred to as notifiable occurrences. For information on the types of occurrences that must be reported and which OTSI may investigate, see Notifiable occurrences.
OTSI is not able to investigate all transport safety incidents and accidents or matters that are reported. The Chief Investigator focuses the agency’s resources on those investigations considered most likely to enhance bus, ferry or rail safety by providing new safety lessons and insights that may be shared.
In some cases, OTSI may request additional information or review an operator’s investigation report into an incident. This may lead to a number of actions, such as the release of a Safety Alert or Safety Advisory to raise industry awareness of safety issues and action to be taken where there are lessons to be shared.
What informs the decision to investigate?
Following the notification of an incident on the NSW transport network, OTSI decides whether to deploy to the incident site. An initial decision to deploy may be for a range of reasons such as the severity of the incident or accident, whether the matter is a known priority safety issue, whether it is in the public interest and considering OTSI resources.
A decision to deploy does not always mean OTSI will undertake a formal investigation. OTSI may decide not to proceed with an investigation after making initial inquiries and assessing them.
The decision to commence an investigation is guided by a broader range of factors which can often be better assessed once more information about the incident is known. The factors considered include for example:
- severity of incident or accident
- potential for consequences to have been more severe
- potential for new safety learning and how widely it could be applied
- existence of system wide issues
- the suitability of OTSI as the agency to investigate
- alignment with safety trends and priority areas
- public interest in the incident or accident
- availability of resources.
Stages of an OTSI investigation
Each investigation type has a slightly different process. The following information relates specifically to incident investigations, however the general principles are similar for the other types of investigation.
While the general principles are similar for each type of investigation (incident, systemic, programmed), there are slight variations to the elements of the investigation process for each type.
Download the diagram to see an overview of the incident investigation process or read more details.
Collection of evidence
Once an investigation is initiated, an Interim Factual Statement outlining the scope of the investigation is published on the OTSI website and shared with Directly Involved Parties (DIPs).
A DIP is a person or organisation who has information or knowledge about the specific incident, accident or issue. They may be able to provide evidence, and insight into what happened or how an event occurred.
The collection of evidence from the occurrence can include requesting documentation, data recordings, records and images, and conducting interviews.
It may be necessary for the OTSI Investigator in Charge (IIC) to revisit the site, and/or visit associated sites such as maintenance areas.
Analysis
This stage involves connecting the occurrence events and uncovering safety issues that may have contributed to the incident. Other associated safety factors may also be uncovered which may lead to the creation of Safety Alerts or Safety Advisories.
A sequence of events relating to the incident is completed during this stage. Hypotheses are developed and tested against the evidence and a draft investigation report is completed.
Review
The draft report is approved internally and is provided to the relevant Directly Involved Parties (DIPs) for review.
This includes verification of:
- the scope of the investigation
- key evidence
- sequence of events
- safety factors map
- the evidence table to ensure the contents of the report match the analysis and findings.
OTSI will review and consider the feedback and make changes were necessary. Changes that are not accepted are communicated to the DIP.
Completion
For investigations carried out under the NSW legislation (Passenger Transport Act 1990 or NSW Marine Safety Act 1998, the final investigation reports must be tabled before both houses of the NSW Parliament by the Minister for Transport.
For investigations done in collaboration with the ATSB under the Transport Safety Investigation Act 2003 (Cth), the final investigation reports may be tabled before both houses of the NSW Parliament by the Minister for Transport.
All OTSI reports, including those done in collaboration with the ATSB are published on the OTSI website. Those reports done in collaboration with the ATSB are also published on the ATSB website.
OTSI publishes its reports and shares safety insights with transport operators, regulators and other industry stakeholders to encourage action to improve safety.
Post-investigation monitoring
We know from stakeholder feedback that awareness of the actions taken by transport regulators, agencies, operators and others to whom OTSI investigation recommendations are directed, can benefit other organisations in the sector to improve their own safety practices. This information is also valuable for assisting OTSI to continue to ensure its recommendations are realistic and achievable.
In August 2023 a new step for organisations identified as ‘directly involved parties’ (DIPs) in OTSI investigations was introduced.
Following the release of a final investigation report OTSI asks DIPs to report back on the work they have carried out to implement committed safety actions or in response to OTSI recommendations. Organisations have 90 days to provide this information.
This is consistent with approaches used by other agencies in Australia and overseas including the Australian Transport Safety Bureau and US National Transport Safety Bureau.
Information provided by DIPs is reviewed by the relevant Investigator in Charge and incorporated into entries on specific investigations on the OTSI website. It may also be used in OTSI presentations to industry about lessons learned and safety improvements driven by incidents and accidents.