In a vehicle system, an inter-vehicle distance between vehicles is controlled by periodically reporting vehicle statuses from a plurality of vehicles to a ground controller and also periodically sending travelling instructions to the plurality of vehicles from the ground controller. Each vehicle stops when detecting failed reception of an instruction from the ground controller and reporting a vehicle status including information that the vehicle has stopped to the ground controller, and the ground controller based on the report received from the stopped vehicle sends a travelling instruction to the stopped vehicle, and based on the report received from the stopped vehicle, also sends a travelling instruction to a vehicle that follows the stopped vehicle so as to avoid interference with the stopped vehicle.