The man was alone in the car, which was on the roof when the police arrived at the scene around midnight on Saturday night.
He was sent to Haukeland University Hospital by air ambulance and did not regain consciousness until he was flown away.
– There were no witnesses to the accident, says operations manager Steinar Hausvik in the West police district to NTB.
The police were notified of the accident at 23.42 on Friday night.
The case is being updated