The purpose of the present invention is to enable a parallel work by a first work vehicle and a second work vehicle to be achieved while measuring the locations of the work vehicles utilizing cheaper satellite location measurement systems. A first satellite location measurement system is mounted on one of a first work vehicle and a second work vehicle, a second satellite location measurement system, which has lower accuracy than that of the first satellite location measurement system, is mounted on a remote control device to be carried on the other of the work vehicles, the actual locations of the first work vehicle and the second work vehicle are measured by the first satellite location measurement system and the second satellite location measurement system, and the locations of the first work vehicle and the second work vehicle are displayed on a display device in the remote control device.