The preferred corridor alignments of the Outer Sydney Orbital have been announced for the following sections: As of August 2021[update], corridor identification will continue for:[2] Grade separated interchanges will be provided at:[6] As part of economic development of Western Sydney, including the construction of the Western Sydney Airport at Badgerys Creek, The Northern Road was proposed to be upgraded to a grade separated motorway.

[7] As part of the State Budget 2014–15, the NSW Government announced a $5.5 billion road package for Western Sydney.

The preferred corridor for the motorway was expected to be announced later in 2014 before plans are made for reserving land.

[8] The Outer Sydney Orbital was split into a few stages for separate corridor identification: In June 2018, it was announced that the Stage 1 orbital will consist of a 10 km tunnel between Cobbitty to Cawdor, and the number of properties to be acquired will drop from 1,247 to 825, with the number of homes affected down to 200, to the relief of the community.

The northern end of the orbital was also truncated from Box Hill to Richmond Road at Marsden Park.