The TSB mandate is fulfilled by conducting independent investigations that can include, if necessary, public inquiries into transportation occurrences. The purpose of these investigations and inquiries is to make findings as to the causes and contributing factors of the occurrences and to identify safety deficiencies. Therefore, recommendations may be made to improve safety and reduce or eliminate risks to people, to property and to the environment. The TSB has the exclusive authority to make findings as to causes and contributing factors when it investigates a transportation occurrence.

In making its findings as to causes and contributing factors of a transportation occurrence, it is not the function of the TSB to assign fault or determine civil or criminal liability. However, the TSB must not refrain from fully reporting on the causes and contributing factors merely because fault or liability might be inferred from its findings. The Act provides that no finding of the Board shall be construed as assigning fault or determining civil or criminal liability, and the findings of the Board are not binding on the parties to any legal, disciplinary or other proceedings.

The TSB reports annually to Parliament through the President of the Queen's Privy Council for Canada.