All westbound lanes of the M4 are closed at South Wentworthville due to a truck and motorcycle crash near the Cumberland Highway.
Motorists are advised to avoid the area and use the Great Western Highway instead.
Motorists already travelling west on the M4 are being diverted at Coleman Street.
Traffic is heavy so motorists should allow plenty of extra travel time.
Emergency services and traffic crews are at the crash site and a medical helicopter is also attending.
For the latest traffic information, download the Live Traffic NSW app, visit www.livetraffic.com or call 132 701.