The Public Transport Authority (PTA) proposes to construct and operate a new 14.5 kilometre (km) dual railway track to extend the existing Thornlie passenger line to Cockburn Central Station on the Mandurah line and duplicate the existing 3 km of single track between Beckenham Junction and Thornlie Station. The proposal requires the relocation of 11 km of freight line within the existing rail reserve.
The proposal requires the construction and operation of two new stations at Ranford and Nicholson Roads in Canning Vale and modification of the existing stations at Thornlie and Cockburn Central. The passenger rail bridge over the Canning River will be duplicated and a principal shared path will be constructed along the new railway.
The proposal would require the clearing of up to 54.9 hectares (ha) of native vegetation, including 22.8 ha in Bush Forever areas. Up to 2.85 ha of Banksia Woodland of the Swan Coastal Plain Threatened Ecological Community, 27.64 ha of black cockatoo foraging habitat and 96 potential black cockatoo habitat trees are proposed to be cleared.