The Ballarat-bound lanes of the Western Freeway are closed at Ballan, due to a serious collision.
Victoria Police is detouring traffic at Ballan-Daylesford Road to allow the air ambulance to land safely.
Motorists are advised to obey the speed limit when detouring via Old Melbourne Road between Ballan and Gordon.
Drivers can return to the freeway at Gordon.
This closure is under Victoria Police control.
The road will open when investigations are complete and it is safe to do so.
Real-time traffic conditions are available at traffic.vicroads.vic.gov.au or via the VicTraffic mobile app.
