Detectives from the Heavy Vehicle Unit continue to investigate a crash which occurred in Malmsbury last week.
Investigators have been told a white Scania prime mover and trailer was travelling north bound on the Calder Freeway when it veered from the road and struck a safety barrier and concrete pillar at the Spring Creek Bridge about 5.20am on 13 January.
The rig then plunged off the bridge between the north and south bound lanes crushing the cabin.
The driver, a 36-year-old man, and sole occupant of the vehicle was trapped for over two hours before being freed and taken to hospital for treatment.
Investigators wish to speak to anyone who saw the truck prior to the crash or the crash.
Anyone with information or dash cam footage is urged to contact Crime Stoppers on 1800 333 000 or submit a confidential crime report at www.crimestoppersvic.com.au.