A vehicle location system utilizing the existing traffic light system

This paper discusses the analysis and design of a vehicle location, monitoring, or communications system that exploits the readily available traffic light system. Optical path transmission of digital data from the traffic-light-heads to passing vehicles permits direct, unambiguous location information to be obtained without any additional spectrum utilization. Location information is processed in the vehicle and combined with vehicle identification and status data for subsequent automatic reporting to a base station. Reporting to the base station is done through the use of the vehicle-to-base communications radios that already exist in vehicles that need such location or status information (such as police cars); or equipment can be readily added because the service and channel assignments already exist, as in the cases of school-bus and public transportation vehicles.