Melbourne-bound traffic on the Western Highway from Ararat will be diverted along the Pyrenees Highway to Avoca and the Sunraysia Highway while crash investigators complete work at the scene of a fatal collision near Trawalla
A Department of Transport media release states drivers should allow for an extra 30 to 40 minutes.
The highway is under police control and will reopen when investigations are complete.
The highway remains open west-bound between Ballarat and Ararat.
A roadworker has died after being struck by a car in Trawalla this morning.
It's believed the roadworker was in the process of setting up for traffic control duties on the on the on-ramp to the Western Highway about 7.20am.
As the 59-year-old Creswick man was at his stationary utility, which was parked in the emergency lane, he was struck by an east-bound Toyota utility.
The driver of the Toyota, a 39-year-old Lucas man, stopped and rendered assistance, however the worker died at the scene.
Major Collision Investigation Unit detectives are on scene.
A WorkSafe spokeswoman confirmed the organisation is investigating the incident.
Anyone who witnessed the incident, or who may have dash cam footage, is asked to phone Crime Stoppers on 1800 333 000 or submit a confidential report at www.crimestoppersvic.com.au.
UPDATE 9am: A person has died in Trawalla this morning after a fatal collision along the Western Freeway.
Police media confirmed the person had died, however was unable to provide any further details at this moment.
The Major Collision Investigation Unit is on the scene.
EARLIER: Police and emergency services have been called to a major incident on the Western Freeway at Trawalla this morning.
Emergency services responded to the incident shortly after 7am and rushed to the scene believed to be near the the on-ramp of the freeway on the Ballarat bound lanes near the small township.
Multiple police units and Ambulance Victoria are on the scene. WorkSafe is also at the location.
It is not yet known if anybody has been hurt in the incident.
The freeway remains open to traffic but the on-ramp is closed.
More to come.