A vehicle awareness system for alerting the driver of a motor vehicle the approaching from the rear side of a motorcycle, and for reporting to the rider of the motorcycle that the driver of the motor vehicle has been alerted. The system comprises (a) a motorcycle unit, located on the motorcycle, for transmitting signals toward the traveling lane of that motorcycle; (b) a car unit, located in the motor vehicle, for receiving signals transmitted from the motorcycle unit, and accordingly supplying one or more output signals indicative of the approach of the motorcycle; (c) first warning means, activated by the output signals, for alerting the driver of the motor vehicle regarding the approach of the motorcycle from the rear side; and (d) second warning means, activated by the same output signals, for signaling the driver of the motorcycle that the first warning means are active.