The realization of a safe road traffic environment is required in order to reduce the number of pedestrian accidents. We propose a prototype pedestrian-to-vehicle communication system which uses a cellular phone and wireless communication to improve the safety of pedestrians. One of the effectual measures against pedestrian-to-vehicle accidents is to make each of pedestrians and drivers find the others and recognize the risk from out of sight and with time to spare for avoidance of accidents. A pedestrian-to-vehicle communication system was developed by using a cellular phone and a car navigation system equipped with GPS and wireless communication function. We focused on intersections as a traffic scene to be covered by the system because pedestrian accidents often occur around intersections at which pedestrians are out of sight of drivers. Over-the-horizon propagation property and communication characteristics of wireless LAN were examined at street intersections and the application potential as the P2P communication method to exchange information between pedestrians and vehicles without infrastructure was shown. After data was exchanged via FOMA in a wide area, information could be exchanged between a pedestrian and a vehicle via WLAN 20m, 100m away from an intersection to different directions in about 20ms. And, the system could give an alarm to pedestrians and cars with collision risk.