Northbound traffic is congested after a crash involving a gas tanker and a car in Bayswater this afternoon.
Nobody is believed to have been injured in the crash on the Tonkin Highway near Guildford Road but Main Roads has warned motorists of heavy delays in the area.
The left lane is blocked northbound and traffic has been reduced to one lane.
The Guildford Road entry ramp to Tonkin Highway has also been temporarily closed to traffic.
Main Roads says traffic is congested and is building up from after Leach Highway to the crash.
Motorists are being advised to allow extra travel time, particularly those heading to the airport.