The proposal is to extend Roe Highway from South Street in Canning Vale to connect to Kwinana Freeway in Leeming over a distance of approximately 4.5 km. The highway is planned as a four-lane dual carriageway (two lanes in each direction), with provision for future upgrading to three lanes in each direction. The land required for any future upgrading will be provided in the median strip. The total footprint of the project area represents 62 hectares (ha).

Approximately 53.9 ha of this area will be cleared in two stages: i) Stage A – in the areas required for bridge construction at South Street, Karel Avenue and Kwinana Freeway, and for the section of highway between Karel Ave and Kwinana Freeway; and ii) Stage B – the remainder of the areas, following translocation of Caladenia huegelii individuals. The remaining 8.1 ha is existing degraded land.