Abstract: A system and method of registering vehicles in a road toll facility is provided with radio transmitter and receiver equipment (7) for microwaves arranged to communicate with vehicle units (12) provided in the vehicles (4), preferably including a transponder. On command from the road toll facility, an identity is obtained from the in-vehicle unit and a toll debiting operation is performed. When a vehicle (4) enters the toll facility, it is detected via the activation of the toll facility radio equipment (7) if the vehicle (4) is provided with a vehicle unit (12) and if it has performed a correct payment operation. Vehicles for which such operations cannot take place are exposed to a successive position determination via video cameras (9) through an image processing in which the vehicle in question is tracked between a predetermined recording site and the location where the payment status of the vehicle has been established via the radio equipment.