In part the second reading of the TSI Act said:
The introduction of the TSI Act will serve to maintain and improve the already excellent safety outcomes of the Australian aviation, marine and rail transport industries. The Act will have a safety benefit for both industry and fare-paying passengers by providing the means for the ATSB to conduct best practice safety investigations in all three modes and thereby help to prevent future accidents. Consequential amendments are made in a short separate Amendment Bill.
The full document can be seen at: