PURPOSE: To prevent traffic accidents in advance, by arranging a belt stuck to a road surface, having a rugged face with a number of lined up and dotted protrusions and also a different color from the center line, on the road surface separately from the center line.

CONSTITUTION: A rugged surface with a plurality of lined-up and dotted protrusions 3a, 3b,... is provided in a belt 1 stuck to a road surface to bring about abnormal sounds or vibration when tires contact the rugged surface. The belt 1 is colored with the same color as brack or brack-brown with the road surface, but a different color from the center line, in order to chiefly distinguish the belt 1 from the center line. The sticking belt 10 on the road face is stuck and fixed at both sides of the center line S. Since tires generate abnormal sounds or vibration due to their contact with the rugged surface of the belt 10 before the tires contact the center line S, alarms of these sounds and vibration are sounded to drivers before crossing over the center line S. In this way, traffic accidents can be prevented in advance.