To prevent an automatic travelling vehicle from disturbing the travel of other vehicles by stopping the mode from being switched to an automatic travel mode after the key position of a key switch is moved from a self position and set between the self position and an ON position.

If an irregular key is inserted into the insertion slot of a main switch 10 and the key position is to be changed forcibly from the self position to a fixed-point passage control side while the vehicle is traveling in an automatic travel mode by setting the key position of the main switch 10 at the self position and detaching the key, the self mode is written to a previous mode storage area 56b of a memory and data indicating that the main switch 10 is at a half position between the self position and ON position are written to a current mode storage area 56a of the memory 56. Through writing of those data, an abnormality detecting and judging process part 55 sends out a control signal inhibiting the automatic travel to a switch input part 59 for a manual changeover switch to stop the mode from being switched to the manual travel mode.