THE Western Highway at Trawalla was blocked for four hours yesterday when a truck jackknifed near Ercildoune Road.
Authorities say the crash happened just before 6.30am.
Ambulance Victoria spokesman John Mullen said the truck driver, aged in his 30s, was taken to Ballarat Health Services Base Hospital with chest soreness, cuts and abrasions.
He remains in hospital under observation.
CFA units from Langi Kal Kal and Beaufort worked to clear the scene as police diverted traffic.
Traffic was diverted via the Pyrenees Highway from Ararat and the Sunraysia Highway from Avoca to Ballarat for more than four hours.
Incident controller Captain Stephen Loader said sand was used to mop up about 700 litres of diesel, which spilled from the B-Double during the jack-knifing.
No other vehicles were involved.
Police are investigating the incident.