A car crash on the Kwinana Freeway south-bound is causing delays during peak hour traffic on Friday afternoon.
The two-car crash just after the Gibbs Road exit in Aubin Grove occurred at 12.30pm but was not cleared until around 3pm.
Fire-fighters and paramedics attended the scene.
A spokeswoman for Main Roads said the traffic was still back-logged at 4pm due the previous lane closures.
"The right lane and right emergency lane was closed," she said.
"Because of that crash and timeframe, the traffic is still doing a catch-up at the moment, resulting in heavy congestion."
The traffic was previously backed up for 12 kilometres to Roe Highway.
One person posted on Facebook around 2pm, "Do not attempt freeway south at all from South Street to unknown as stuck at Russell Road after 45 minutes and three ambulances and two firies passed us."
St John Ambulance was contacted for comment.
#KwinanaFwy southbound from #SouthSt to #GibbsRd - EXPECT DELAYS - heavy congestion #perthtraffic
— Main Roads WA (@Perth_Traffic) November 18, 2016