A crew from Hemel Hempstead fire station was called to action in the early hours of Saturday morning after reports of a car ablaze.
The emergency call was received at 4.51am and the blazing vehicle, found in the middle of the A414 St Albans Road, was put out by firefighters using a hosereel jet.
They had cleared the scene by 5.09am.
Nobody was hurt in the fire, which has been recorded as an accident.