Section 257.691 - Clearance and marker lamps and reflectors; visibility(a) Every reflector upon any vehicle referred to in section 689 of this chapter shall be of such size and characteristics and so maintained as to be readily visible at nighttime from all distances within 500 feet to 50 feet from the vehicle when directly in front of lawful upper beams of headlamps. Reflectors required to be mounted on the sides of the vehicle shall reflect the required color of light to the sides, and those mounted on the rear shall reflect a red color to the rear.(b) Front and rear clearance lamps shall be capable of being seen and distinguished under normal atmospheric conditions at the times lights are required at a distance of 500 feet from the front and rear, respectively, of the vehicle.(c) Side marker lamps shall be capable of being seen and distinguished under normal atmospheric conditions at the times lights are required at a distance of 500 feet from the side of the vehicle on which mounted.1949, Act 300, Eff. 9/23/1949 .