1. An unmanned load transporting vehicle comprising: a guide belt laid on a floor on which said vehicle is run, said guide belt comprising a plurality of reflecting segments comprising a plurality of bar codes representing corresponding instructions including a halt instruction, a deceleration instruction and turning instructions; a video camera installed on an upper portion of the vehicle, said camera being directed to receive light reflected from said guide belt; controller means installed on the body of the vehicle receiving an output signal from said camera for controlling running of said vehicle in response to said output signal from said camera.