PROBLEM TO BE SOLVED: To build an operation safety system not depending on the attention force of a driver at a frequency modulation type ATS-S type system.
SOLUTION: A frequency modulation type ATS ground apparatus transmits a protection function command to a vehicle by digital information wave transmission in addition to an alarm function command by frequency modulation transmission. The alarm function is a function to alarm that the aspect of a signal in front of an advancing train is a stop aspect. A protection function is a function to cause an on-vehicle apparatus to produce a brake pattern and automatically output a brake command in an on-vehicle place when a train continues continuous running for the train exceeding the pattern speed. In addition to the frequency modulation coil 7 of the ATS ground apparatus to transmit an alarm function command to a vehicle, a digital information wave transmission coil 9 is provided to transmit a protection function command to a vehicle.