A device for detecting, monitoring and/or controlling racing vehicles on a preferably multi-lane racetrack, having at least one sensor unit which is arranged countersunk under the surface of a carriageway. The at least one sensor unit is mounted on a guide element which can be inserted into a receptacle space under the carriageway in the transverse direction with respect to the carriageway, from the lateral edge of the carriageway. In this context, cables, lines or the like can be pre-assembled in a complete state with the at least one sensor unit and can be inserted under the carriageway from the side together with the guide element, with the result that there is no need for any separate laying of cables or even for a cable connection once the sensor is in position.