PURPOSE: To interrupt traffic transmission signal output and area discrimination in response to a control signal and to make the operation of reception stable, by AM-detecting the area discriminating signal and the traffic information transmitting signal and producing the control signal when the detected output is a prescribed level or more.

CONSTITUTION: A traffic information station discrimination signal SK including an area discriminating signal BK from an FM detector and a traffic information transmission signal DK are in AM-detection at an AM detector 1, and the signals BK and DK in AM detection are extracted at a BK signal filter 2 and a DK signal filter 3, respectively, and the output of the filters 2, 3 is applied to gates 8, 9. The signals BK and DK AM-detected at the discriminator 6 are compared with a specified threshold value, the waveform more than the threshold value is converted into a DC level at a smoothing device 7, the DC level controls the gates 8, 9, the detected output from a BK signal detector 4 and a DK signal detector 5 is interrupted and the receptive operation of the signal SK is made stable.