EMERGENCY crews have closed the Glenelg Highway at Lake Bolac this morning after a bad smash, where a car has hit a tree in the heavy fog.
A man in his 60s was the sole occupant of the vehicle, which hit the tree on its roof.
The crash occurred on the corner of Murray and Graham roads, west of the town.
Ambulance crews were called to the scene at 7.20am.
They are joined by police and SES crews, who are trying to remove the car from the tree.
Rural Ambulance Victoria spokesman John Mullen said the man was in a critical condition and was going to be stabilised before he could be airlifted to Melbourne's The Alfred Hospital.