To prevent a traffic lane from being closed at the time when a line controller installed at every traffic lane fails and when the failure part is repaired or exchanged.

The line controller 20 of this ETC system is provided with a first radio communication processing part 30 comprising a master antenna 31, a radio controlling part 32, a main controlling part 33, a failure detecting part 34 detecting the failure of each of these parts, a power supply part 35 feeding power to each of the parts, etc., a 2nd radio communication processing part 40 operating in the same manner as the part 30 and comprising a slave antenna 41, a radio controlling part 42, a main controlling part 43, a failure detecting part 44, a power supply part 45, etc., and a monitoring and controlling part 50 which makes the part 30 disable and the part 40 enable and switches operating processing parts, for instance, in the case of receiving a failure detection signal from the part 34.