A car rollover on Kwinana Freeway southbound at Mundijong Road, Baldivis has caused heavy traffic.
Vehicles are in the left and right emergency lanes and traffic is busy on approach.
Towing services are on site and motorists have been advised to drive with caution.
Another crash on Roe Highway northbound after Kenwick Link, Beckenham has reduced traffic to a single lane.
Towing services are on site and cars are backed up for several kilometres.
A crash on Welshpool Road East westbound at Brook Road, Wattle Grove has been cleared.
The left lane has been reopened and traffic is moving steadily.