To prevent mutual interference when a manned car travels in the same traveling course with an unmanned car by providing a specific unmanned car controller, etc., for the unmanned car and providing respectively specific manned car controller, a warning means for the manned car.

The unmanned car is provided with the unmanned car controller 10, an unmanned car position detecting means 11, an unmanned car transmitter- receiver 12 and a speed controlling means 13. The unmanned car controller 10 travel-controls the unmanned car so as to keep the distance between with manned car near the unmanned car more than a prescribed value. On the other hand, the unmanned car is provided with the manned car controller 20, a manned car position detecting means 11, a manned car transmitter-receiver 22 and the warning means 23. The manned car controller 20 instructs an operator to keep the distance between with an unmanned car near the manned car more than a prescribed value. the warning means 23 warns an operator to detour, decelerate, stop, etc., the car based on a warning command signal from the manned car controller 20.