A 34-year-old man died after his ute crashed through a safety barrier on the Mitchell Freeway yesterday - in a shocking crash that caused northern suburbs traffic chaos.

It is understood to be the 100th fatality on WA roads this year.

Police closed Mitchell Freeway from Karrinyup Road for several hours as major crash squad officers investigated the crash, which happened just before 3pm.

Trains on the Joondalup line between Stirling and Warwick stations initially stopped as well.

Police say the late 2000s model Toyota Hilux ute was travelling south on the freeway when it collided with a concrete barrier.

The driver was taken to Royal Perth Hospital but later died.

Camera Icon Shocked train passengers look over the wreckage of the car. Credit: Ross Swanborough, The Sunday Times

Police later confirmed the driver was the sole occupant of the vehicle, which rolled and went through a safety barrier - nearly on to the train tracks.

The left lane of the freeway reopened just before 7pm Saturday and the rest of the lanes were opened later in the the night but the tragic crash resulted in significant traffic dramas.

The Mitchell Freeway southbound snaked back several kilometres from Karrinyup Road - there were estimates of an 8km queue - and traffic flow on connecting roads, including Reid Highway, was also affected.

Witnesses to the crash are being sought and are asked to contact Crime Stoppers on 1800 333 000 or at www.crimestopperswa.com.au.

Train services were eventually able to restart at a reduced speed.

Camera Icon Emergency services personnel at the scene of the crash near Karrinyup Road. Credit: Marie Nirme, The Sunday Times

Earlier, a car had rolled on Kwinana Freeway northbound near Safety Bay Road in Baldivis.

The accident happened about 2.20pm.