Traffic is moving again on the Mitchell Freeway after a police pursuit and crash caused massive peak hour disruption for commuters earlier this morning.
The accident happened in the southbound lanes of the freeway just short of the Scarborough Beach flyover at around 5.30am.
Tens of thousands of commuters were caught up in the gridlock and faced lengthy delays.
Police say the incident began when the driver of a black Mazda sedan was noticed behaving suspiciously near Karrinyup Shopping Centre.
When they followed the driver onto Karrinyup Road and attempted to pull over the vehicle, it sped off towards the freeway.
The vehicle travelled in the emergency lane before colliding with a BMW, losing control and sliding down an embankment.
The driver of the Mazda then fled on foot.
Police are also seeking the driver of the BMW for more information.
— Main Roads WA (@Perth_Traffic) March 21, 2018