To obtain proper consistency between car-type discriminated results and results of communication even when vehicles mounted with on-vehicle devices and vehicles mounted with no on-vehicle device run in a mixing state.

A car-type discriminating device 1 integrally transmits car-type discriminated results obtained from passing vehicles and results of communication between on-vehicle devices 8 and an on-road antenna 7 to a traffic lane controller 10. When a vehicle mounted with no on-vehicle device passes, the device 1 transmits information indicating 'absence of communication' to the controller 10 together with the car-type discriminated results. Upon receiving the information, the controller 10 performs processing to be performed for a vehicle mounted with no on-vehicle device 8. When two or more vehicles mounted with on-vehicle devices 8 pass, the discriminating device 1 transmits information indicating the 'results of communication (of two device)' together with the car-type discriminated results and the controller 10 performs processing to be performed for two vehicles mounted with on-vehicle devices 8.