Main Roads WA has awarded Laing O'Rourke and BG&E a $134 million construction contract for the Armadale Road to North Lake Road bridge project.
The project will involve construction of a new bridge over Kwinana Freeway connecting Armadale Road and North Lake Road.
The state government said the works have an overall budget of $237 million and would create 1,400 jobs.
Construction of the project is set to begin in late 2019 following a period of detailed design.
The existing interchange at Kwinana Freeway is the 10th most congested intersection in the metropolitan area, according to the state government.
Armadale Road will also be upgraded from Tapper Road to Kwinana Freeway, passing over the intersection of Tapper Road with a new bridge, and under the intersection of Solomon Road via a trench structure.
Both projects were announced as part of the 'Boosting Jobs, Busting Congestion' package launched by the state government, when funding was redirected from the previous government’s Perth Freight Link project
In addition to the North Lake Road bridge, the government said work was progressing on the final section of the $145 million Armadale Road widening project.
The four-way signalised Armadale Road and Nicholson Road intersection will soon be converted to a roundabout with a four-lane bridge (two lanes in each direction) over Nicholson Road.
Premier Mark McGowan said the Armadale Road to North Lake Road bridge project was a vital election commitment.
"The Armadale Road upgrade is just one of a number of significant projects under way in Perth's southern suburbs, which will reduce congestion and lead to safer and more efficient journeys around our suburbs,” he said.
"Workers from the cancelled Roe 8 project were transferred to the Armadale Road dual carriageway project, allowing the project to be completed sooner.”