A schedule changer executes, as a schedule change process for changing a normal operation schedule, a cut-in change process in which a plurality of operating vehicles are divided into a sequence of an advanced vehicle line group for which a departure target time is advanced from a departure target time determined based on the normal operation schedule, and a sequence of a delayed vehicle line group for which the departure target time is delayed from the departure target time determined based on the normal operation schedule, and an inter-vehicle space between the advanced vehicle line group and the delayed vehicle line group is enlarged for an additional vehicle.