The principal purpose of the Transport Accident Investigation Commission (TAIC) is to determine the circumstances and causes of accidents and incidents with a view to avoiding similar occurrences in future, rather than to ascribe blame to any person. (s4 of the TAIC Act)

TAIC is the New Zealand Crown Entity responsible for the independent investigation of significant aviation, rail, and marine accidents and incidents. TAIC does not investigate road accidents or incidents except when the circumstances may have significant implications for the safety of, for example, the rail transport system.