A control method for monitoring the toll-compliant operation of a first vehicle that is subject to tolls, involving a second vehicle participating in traffic on a road traveled on by the first vehicle, and a central data processing means in a toll system, which uses vehicle equipment, which is to be carried along by vehicles that are subject to tolls and which serves to collect tolls and which, when properly operated, generates at least one piece of toll information, which is representative for travelling on the road or a region comprising said road with the vehicles that are subject to tolls, characterized in that the second vehicle - while it drives on the road, automatically generates at least one piece of control information, which is representative for travelling on the road or a region comprising said road with the second vehicle, - automatically captures an image of the first vehicle while it drives on the road, - determines the text data of a license plate of the first vehicle from the image data of the captured image of the first vehicle, and - transmits the text data of the license plate of the first vehicle and the control information via a mobile radio network to the central data processing means, and the central data processing means - uses the text data of the license plate of the first vehicle transmitted by the second vehicle to determine a mobile radio communication address of vehicle equipment associated with the license plate, and - makes at least the attempt via said mobile radio communication address to request at least one piece of toll information from the vehicle equipment, which is relevant for the proper operation thereof, via a mobile radio network, - compares this at least one piece of toll information of the vehicle equipment to the control information, which was provided to the central data processing means by the second vehicle together with the text data of the license plate of the first vehicle, and - in the event that this comparison fails, requests from the second vehicle that image data of the captured image, which formed the basis for the determination of the text data of the license plate of the first vehicle, via a mobile radio network. - while it drives on the road, automatically generates at least one piece of control information, which is representative for travelling on the road or a region comprising said road with the second vehicle, - automatically captures an image of the first vehicle while it drives on the road, - determines the text data of a license plate of the first vehicle from the image data of the captured image of the first vehicle, and - transmits the text data of the license plate of the first vehicle and the control information via a mobile radio network to the central data processing means, - uses the text data of the license plate of the first vehicle transmitted by the second vehicle to determine a mobile radio communication address of vehicle equipment associated with the license plate, and - makes at least the attempt via said mobile radio communication address to request at least one piece of toll information from the vehicle equipment, which is relevant for the proper operation thereof, via a mobile radio network, - compares this at least one piece of toll information of the vehicle equipment to the control information, which was provided to the central data processing means by the second vehicle together with the text data of the license plate of the first vehicle, and - in the event that this comparison fails, requests from the second vehicle that image data of the captured image, which formed the basis for the determination of the text data of the license plate of the first vehicle, via a mobile radio network.