PURPOSE: To prevent rear-end collision by fitting plural reflecting plates to an outer side wall of a steep curve of a roadway at a height of a lamp of car body at a predetermined interval so as to recognize a front vehicle being out of sight of a driver.

CONSTITUTION: Plural reflecting plates 4... are fitted to a curved side wall 5 of a steep curve path 2 in a tunnel 1 at a height almost equal to a tail lamp mount height of an automobile 3 at a predetermined interval in a line. Thus, a backward vehicles can recognize a tail lamp of a forward vehicle displayed on the reflecting plates 4 even out of sight due to a curve thereby avoiding a rear-end collision.