The traffic chaos along the Mitchell Freeway is starting to ease after a truck lodged under the Hay Street overpass on Thursday morning was cleared.

A truck towing machinery became wedged underneath the bridge at the the Mitchell Freeway southbound entrance just after 8am.

The truck took out a chunk of the bridge. 

Truck crashes into the Hay Street bridge on Mitchell Freeway. Photo: 6PR

At one stage just before lunch, traffic was banked up all the way to Erindale Road in Balcatta.

Advertisement

Around 2pm, traffic was only backed up to Vincent Street.

Main Roads said the right and centre lanes on Mitchell Freeway are still blocked.

Traffic is heavy on approach and delays are to be expected.

Motorists are advised to avoid the area and find alternate routes.