PURPOSE: To perform selective reception automatically and to transmit traffic information of outgoing and incoming driving cars, by locating the 1st and 2nd trigger antennas transmitting the 1st and 2nd signals sequentially at both ends of a road broadcasting sections locally provided along the road.

CONSTITUTION: Road broadcasting section are locally provided along a road, and the 1st trigger antennas 7 and 9 transmitting the 1st trigger signal and the 2nd trigger antennas 8 and 10 transmitting the 2nd signal are provided before the outgoing and incoming roads of the broadcasting sections. Antennas 1 and 2 transmitting outgoing and incoming information and antennas 5 and 6 transmitting a termination signal are provided to the broadcasting section. The carrier wave frequency f0 of 1st signal from the antennas 7 and 9 is modulated in a frequency f1, and the carrier frequency f0 of 1st signal from the antennas 8 and 10 is modulated in a frequency f2. A receiver provided on a running car receives the 1st and 2nd signals, allowing automatically to receive incoming and outgoing traffic information selectively.