A method operates an automatic train control system which has an electronic signal box, a balize and a frequency track circuit. To configure the train control system so as to be constructed from components of the European train control system and of the frequency track circuit without substantial additional development effort, the balize is acted upon by indicator messages of a first type of the electronic signal box via an actuation module for modular elements having an addressable memory for the number of currently free block route segments. Indicator messages of a third type are created from indicator messages of a second type. A functional relationship between the addresses of the memory and code information of the frequency track circuit is taken into account during the creation of the third indicator messages. A transmitter of the frequency track circuit is acted upon as a result of the third indicator messages.