PURPOSE: To grasp the prediction of the front line state of a train by transmitting ATC information to the train with the carrier wave of higher frequency than that in the past to obtain much information, and generating a distance/speed curve from the point ATC information on the train.

CONSTITUTION: The carrier wave of 80Hz rarely affected by the feeding frequency is AM-modulated by the frequency of several Hz, a track circuit is constituted with this track circuit signal to detect a train, and point ATC information is superimposed near the transmission end of the track circuit and transmitted/received to the train. A ground device detects the train with the track circuit arranged continuously, it determines the type of the 80Hz code signal S to be transmitted to the track circuit behind the train, it finds the interval of the track circuit unit between the front train position and the track circuit unit between the front train position and the track circuit, and it generates the point ATC information. An on-vehicle device generates a distance/speed curve based on the point ATC information received by point control and the train speed so that the train can be stopped before it collides from behind the preceding train, and a brake is operated to drive the train along the curve.