A truck crash on the Mitchell Freeway in Clarkson put peak-hour traffic into chaos on Thursday afternoon.
A major exit of the freeway north had to be closed after the truck jack-knifed about 1pm, blocking lanes and spilling about 50 litres of diesel.
It took emergency crews about five hours to clear the crash site, with the freeway opening again about 6pm.
A Main Roads WA instant response was sent to the scene to assist in the clean up.
Drivers were encouraged to exit the freeway at Hodges Drive to avoid getting stuck in a traffic jam.
It is believed no one was injured in the crash.
