Vehicle classification equipment for expressway toll collection station

This paper describes equipment that automatically classifies vehicles passing through expressway toll collection stations. The equipment is composed of an axle grouping device which separates a group of vehicles from another using an optical screen, a wheel sensor which is embedded in the roadbed to detect wheel data such as, widths, positions of wheels, and a controller which processes signals from these devices, and transmits the class of the vehicle to an upper level system. This equipment has a special feature which enables it to measure the wheel data with high resolution applying pressure conductive rubber, a new switching material, in the wheel sensor. It is now being used as a sensor of the new toll collection system developed by the Japan Highway Public Corporation.