Abstract: A collision avoidance system providing to each properly equipped vehicle an indication of the locational direction, heading, and relative velocity of other similarly equipped vehicles or stationary objects. Each vehicle in the system is equipped with a transponder module which transmits information data relating to that vehicle, and receives information data relating to the other similarly equipped vehicles. A central reference time signal transmitter is provided for transmitting a reference timing signal which effectively synchronizes each of the transponder modules. Upon receiving the reference timing signal, the transponder module subsequently transmits information data relating to that particular vehicle. Each of the transponder modules is allocated a unique time period for transmission of its information data.