A method performs a mixed operation of a track-bound line section. Trains that are equipped with a train protection system run there. In order to guide trains that are not equipped with the train protection system through the line section, provision is made for switches to be set as a protecting switch for the purpose of following-move protection. However, the switch is reset again before the passage of the unequipped train, wherein the respective block section of the line section must be free again at this time point. The method therefore allows mixed operation of equipped and unequipped trains while at the same time requiring limited component expense for lineside train protection apparatus.