The Department of Main Roads (DMR) was an agency of the New South Wales Government, responsible for planning, constructing and maintaining major road infrastructure. The DMR directly managed highways and major roads and provided funding to local councils for regional and local roads. The agency was merged with other agencies to form the Roads & Traffic Authority in 1989.

The Roads & Traffic Authority (RTA) was an agency of the Government of New South Wales responsible for major road infrastructure, licensing of drivers, and registration of motor vehicles. The RTA directly managed state roads and provided funding to local councils for regional and local roads. In addition, with assistance from the federal government, the RTA also managed the NSW national highway system. The agency was abolished in 2011 and replaced by Roads & Maritime Services.