A 44-year-old Cambridge man is lucky to be alive after he drove his car over a Greensville bluff and plunged approximately 10 metres into Spencer Creek this morning.

Hamilton police say the man on his way to work in Burlington and may have fallen asleep at the wheel.

He drove straight through a T-intersection at Hwy 8 and Brock Road.

Constable Robert Norrie was first on scene and scrambled down the heavily wooded embankment.

Norrie was startled when the man began to get himself out of the vehicle.

The officer said the man told him he may have been unconscious for up to two hours before anyone realized he'd veered from the road.

The hood of the car was in the water. The airbags had deployed.

A fence board penetrated the windshield missing the man's head by mere inches.

"I'd be buying lottery tickets if I was this guy," said Hamilton Fire District Chief Pat Gallacher.

The man was taken to hospital with what rescuers believe to be non-life threatening injuries.