The relative position between a vehicle and an extension unit located outside the vehicle is detected, and a command touch operation for operating the vehicle with a remote operation device is set in accordance with the detected relative position. The touch operation of an operator is detected by a touch panel of the remote operation device, and a determination is made as to whether or not the detected touch operation is the command touch operation. When the touch operation is the command touch operation, the vehicle is controlled to execute autonomous travel control. The vehicle has an autonomous travel control function.