The great northern highway has been closed for more than five hours after a truck carrying a large piece of mining equipment lost its load early this morning.
The cargo, believed to be mining equipment, belongs to BHP.
Main Roads WA advised the road was closed at 3am.
BHP spokesman Antonios Papaspiropoulos this morning confirmed the vehicle belonged to BHP but did not say what action the company was taking to clear the road.
A Main Roads spokesman said specialist lifting equipment was needed to move the truck.
The Great Northern Highway is closed between Cajarina Road and Wallwork Road in Wedgefield, Main Roads said. A detour is in place via Wallwork Road, North Circular Road and Hamilton Road.
Emergency services and temporary Traffic Management are on site, and Main Roads has asked drivers to obey all speed restrictions and directives given by traffic controllers.
Luke Dillon tweeted a picture of the upturned load at 6.47am.