A pedestrian was airlifted to hospital in critical condition after he was struck by a vehicle in Caledon this morning.

It happened in the area of Highway 10 between The Grange Sideroad and Old Baseline at around 8:15 a.m.

Police say a silver Toyota Highlander was heading northbound on Highway 10 when it left the road for unknown reasons and hit a vehicle parked on the east shoulder.

When the driver of the Toyota got out of the vehicle and crossed Highway 10 on foot, he was struck by a green Hyundai Santa Fe heading southbound.

Ornge air ambulance confirmed that man, who is believed to be in his 70s, was taken to a trauma centre for treatment. His injuries are believed to be life-threatening.

One lane is blocked in each direction on Highway 10 due to the crash, Ontario Provincial Police say.