Data processing device having a receiving device and a determination device, the receiving device being coupled to the determination device, - a detection device (60, 95) and a transmitting device (65, 90) connected to the detection device (60, 95) being provided for at least one vehicle (50, 55, 120), - the detection device (60, 95) being designed to detect positions of the vehicle (50, 55, 120), to determine whether the road section (80, 115) in front of the respectively detected position is free of a vehicle (50, 55, 120) driving in front, and to provide the transmitting device (65, 90) with the information relating to the respectively detected position and the road section (80, 115) assigned to the respectively detected position, - the transmitting device (65, 90) being designed to transmit the information relating to the respectively detected position and the road section (80, 115) assigned to the respectively detected position, as provided by the detection device (60, 95), to the receiving device, - the receiving device being designed to receive the information relating to the respectively detected position of the at least one vehicle (50, 55, 120) and the information relating to the road section (80, 115) in front of the vehicle (50, 55, 120) with regard to a free journey of the vehicle (50, 55, 120), which is assigned to the respectively detected position, - the determination device being designed to determine an optimum speed which is to be determined and is assigned to the respectively detected position on the basis of a detected driving speed (v 1/2) of the vehicle (50, 55, 120) assigned to the respectively detected position, - the determination device being designed to take into account only that driving speed of the vehicle (50, 55, 120) which is linked to the information relating to a free journey for the road section (80, 115) in front of the respectively detected position in order to determine the optimum speed for the respectively detected position. - a detection device (60, 95) and a transmitting device (65, 90) connected to the detection device (60, 95) being provided for at least one vehicle (50, 55, 120), - the detection device (60, 95) being designed to detect positions of the vehicle (50, 55, 120), to determine whether the road section (80, 115) in front of the respectively detected position is free of a vehicle (50, 55, 120) driving in front, and to provide the transmitting device (65, 90) with the information relating to the respectively detected position and the road section (80, 115) assigned to the respectively detected position, - the transmitting device (65, 90) being designed to transmit the information relating to the respectively detected position and the road section (80, 115) assigned to the respectively detected position, as provided by the detection device (60, 95), to the receiving device, - the receiving device being designed to receive the information relating to the respectively detected position of the at least one vehicle (50, 55, 120) and the information relating to the road section (80, 115) in front of the vehicle (50, 55, 120) with regard to a free journey of the vehicle (50, 55, 120), which is assigned to the respectively detected position, - the determination device being designed to determine an optimum speed which is to be determined and is assigned to the respectively detected position on the basis of a detected driving speed (v 1/2) of the vehicle (50, 55, 120) assigned to the respectively detected position, - the determination device being designed to take into account only that driving speed of the vehicle (50, 55, 120) which is linked to the information relating to a free journey for the road section (80, 115) in front of the respectively detected position in order to determine the optimum speed for the respectively detected position.