Abstract: Device for measuring the separation, between any vehicle of a number of vehicles and the preceding vehicle along a stretch and for a direction, includes a reference conductor and a measuring conductor, along the stretch, the latter including a number of serial separate sections. Each section is electrically-connected to the previous section, via a diode. A constant current generator is provided in each vehicle, whose contacts are each connected to a section of the measuring conductor, corresponding to the position of the vehicle and to the reference conductor, via first and second moving contacts. Each second electric contact is connected to a segment, following the section, lying behind the first electrical contact, the direction of travel, via a corresponding third moving electrical contact. The contacts of the constant current generator form an output, which provides a voltage signal correlated to the distance between the relevant vehicle and the previous vehicle.