The Golden Highway is closed in both directions east of Dunedoo due to a serious truck crash and fire near Fairfield Lane.
Eastbound traffic is being diverted via Black Stump Way and Vinegaroy Road to rejoin the highway, Live Traffic NSW reports on its website on Sunday afternoon.
Westbound traffic is being diverted via Vinegaroy Road and Black Stump Way.
The diversion is suitable for all vehicles.
Emergency services and the Roads and Maritime Services are at the scene.
Motorists are advised to allow extra travel time.