Disclosed is a spoiler which constitutes a traveling safety device for a motor vehicle. A length of the conductive voltage-measuring terminal is greater than a thickness of the first pair of unit separators, in the stack direction. Four or more fins are mounted within the tube and function to inhibit the use of the gun to fire balls having a diameter smaller than that of balls which are intended to be shot from the gun. The move forward lighted arrow indication is color-coded and remains on for a period of about 0.