PURPOSE: To obtain the method quickly securing a visual field of a range corresponding to a scope of a path of an unattended truck whose drive and steering are controlled by remote control at a low cost.

CONSTITUTION: The selecting state of a selection changeover switch of a video switcher 38 is momentarily switched in interlocking with the operation of an operating lever 28 of a joy stick 27 controlled when the steering of a carrier truck is executed. Then a video image from two sets of television cameras 31, 32, and 32, 33, and 33, 34, and 34, 35 and 35, 36 adjacent to each other picking up a visual field of a range corresponding to a scope of a path of a carrier truck subject to steering through remote control is displayed on a left eye display device 39L and a right eye display device 39R placed before a left eye and a right eye of the operator 40.