The major upgrade to the three kilometre section of Wanneroo Road, south of Joondalup Drive is now complete and open to traffic.
Transport Minister Simon O'Brien said the $18m project would ultimately improve traffic flow, reduce congestion and improve safety on the extremely busy road.
The three kilometre long section of Wanneroo Road from Wallawa Street to Joondalup Drive consisted of one lane in each direction, integrating with a dual carriageway at the southern end.
Under this project, the road was duplicated to create a dual carriageway with two lanes in each direction separated by a median of varying widths.
This involved construction of two additional lanes on the western side of the existing road, adjacent to housing and the Yellagonga Regional Park. The existing lanes have also been upgraded to current standards.
The major benefits of the project included: