Abstract: To identify a moving car for switching it from a main line to a spur, a signal indicator on the car tuned to a selected frequency activates a signal pickup apparatus which is located on the main line ahead of the spur. The signal pickup apparatus emits a radiation field sweeping a range of frequencies including the same frequency as that of the signal indicator. The signal pickup apparatus includes circuitry which responds to the activation by the signal indicator to operate the switch of the spur for the diversion of the moving car.