Abstract: A cashless toll collection system and method that detects vehicles using transponders for prepaid customers and cameras for casual or non-transponder equipped vehicles. The system has a plurality of roadside toll collectors, one or more toll transaction processors, and a revenue management system. Each roadside toll collector has a vehicle to roadside communications system that communicates with transponders disposed in transponder equipped vehicles and generates entry and exit transaction reports indicating the entry and exit locations and times of the transponder equipped vehicles. Each roadside toll collector has a plurality of license plate cameras that selectively provide video images of license plates of vehicles that are not equipped with a transponder.

Abstract: Data transmissions between a transponder and a reader of a toll collection system are minimized while the transponder moves through a communication zone of the system. A plurality of dimensionally programmable detection regions, are defined within the communication zone. Detection criteria are also defined that indicate whether the transponder transitions into, out of, or both into and out of one of a plurality of "in" detection regions. Then it is determined if the current geolocation of the transponder is within any of the detection regions. The current location of the transponder is compared to the previous location of the transponder. If a change in the location of the transponder occurs and one of the detection criteria has been met, a detection region report message is generated.

Abstract: A sequential messaging method for use in a vehicle detector and classification system having a processor and that uses first and second beams to detect transitions of front and rear ends of a vehicle. The method comprises detecting the vehicle when its front end breaks the first beam, assigning a new vehicle ID number to the vehicle, and transmitting a vehicle detection report containing the vehicle ID number to the processor. The vehicle is detected when its front end passes the second beam, and a vehicle detection update report is transmitted to the processor comprising left edge position, right edge position, range to each edge, vehicle height, and vehicle speed, all of which are derived from the beams reflected from the vehicle. The vehicle is detected when its rear end passes the first beam, and a rear vehicle detection report is transmitted to the processor comprising the left edge position, right edge position, range to each edge, vehicle height, and vehicle speed.