Police say a 69-year-old Tyrendarra man died after suffering a 'rapid onset' of a medical episode, which caused him to run his Jeep SUV off the Princes Highway at Codrington just after 1pm.

His wife, a 68-year-old woman also from Tyrendarra, was in the passenger side but was uninjured in the crash.

"The male driver appeared to have had a rapid onset of a medical issue which caused him to run off the road on the north side of the Princes Highway," Leading Senior Constable Chris Vorwerk of Port Fairy police said.

"His wife was assisted by members of the public to remove the male from the car.

"Passerbys performed half an hour or more of CPR on him but he was unable to be revived."

Leading Senior Constable Vorwerk praised the quick-thinking actions of the public.

"Victoria Police would like to thank members of the public for their assistance with the terrible situation by offering very professional CPR.

"It's very fortunate there were no oncoming vehicles or the situation could have become catastrophic."

He said the SUV almost rolled over completely.

"The driver was unable to negotiate a gentle right hand bend, and the car's gone off through the oncoming lane and off a north side embankment," he said.

"It almost rolled but came to rest at a 45-degree angle.

"There were no injuries sustained by any other party and no actual collision with an object."

Police are preparing a report for the coroner.

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