The Second Edition Australian Design Rules (ADRs) are national standards for vehicles that first came into effect on 1 January 1969 as endorsed by the then Australian Transport Advisory Council (ATAC). The ATAC recommended the Second Edition ADRs to the Commonwealth, State and Territory Governments for vehicles being supplied to the Australian market. The Second Edition ADRs only applied to vehicles manufactured from 1 January 1969 onwards and were selectively applied by each state and territory. From the time of 1 July 1988 onwards, the Second Edition ADRs were increasingly superseded by the Third Edition ADRs.

For vehicles manufactured up until July 1989, the application of the ADRs is the responsibility of the state and territory governments. Vehicle users should consult with their state or territory transport authority for the Second and Third Edition ADRs that apply to these vehicles.

For vehicles manufactured after July 1989, the application of the ADRs is the responsibility of the Australian Government under the Motor Vehicle Standards Act 1989. Vehicle users should consult with this department for the Second and Third Edition ADRs that apply to these vehicles.