All southbound lanes of Nelson Bay Road are closed at Williamtown due to a car crash.
The road is closed south of the roundabout at Lavis Lane.
Motorists can use Cabbage Tree Road and Tomago Road instead to the Pacific Highway.
Motorists should also allow extra travel time and follow the directions of emergency services and transport crews on site.
Local buses are also diverting from their normal routes on Nelson Bay Road, so passengers should allow extra travel time.