Abstract: A communication system for a vehicle traveling over a road surface is provided with at least one detector for sensing speed detection signals impinging on the vehicle, to monitor the speed of the vehicle or a nearby vehicle. A radiofrequency transmitter communicates the detector output to a receiver adjacent the passenger compartment of the vehicle. The receiver controls one or more annunciators to output one or more annunciator indications to the system user. The radiofrequency transmitter in one embodiment directs transmissions along a ground skip path, reflecting information over the road surface so as to enter the receiver located in or near a passenger compartment of the vehicle. A wireless control unit provides indication of system operating status and allows a user to input commands to the system.