Interpretation ID: aiam3633
Vice President
Don Vesco Products
Inc.
7565 North Avenue
Lemon Grove
CA 92045;
Dear Mr. Guzzetta: This is in reply to your letter of September 15, 1982, asking about th legality of 'covering of a headlamp on a motorcycle with a clear cover.'; You reported that manufacturers of motorcycles and fairings ar producing such covers. The National Highway Traffic Safety Administration views this practice as prohibited and will take appropriate steps to make its views known. The legal authority for this is based upon a requirement of the SAE incorporated by reference in Motor Vehicle Safety Standard No. 108 or, alternatively, paragraph S4.1.3 of that standard.; SAE Standard J580 (both a and b versions), *Sealed Beam Headlam Assembly*, is incorporated by reference in Tables I and III of Standard No. 108 as one of the standards pertaining to headlamps for use on passenger cars, trucks, buses, and multipurpose passenger vehicles. A paragraph in each version states that, 'When in use, a headlamp shall not have any styling ornament or other feature, such as a glass cover or grill, in front of the lens.' SAE J580a applies to all sealed beam headlamps, while the scope of J580b is considerably narrower, including only those not covered by SAE J579c.; The principal referenced SAE material for motorcycle headlamps is J584 *Motorcycle Headlamps*. As options, both J584 and S4.1.1.34 of Standard No. 108 allow, in effect, a motorcycle to be equipped with one half of any sealed beam system permissible on four-wheeled motor vehicles.; Paragraph S4.1.3 of Standard No. 108 forbids the installation o additional equipment 'that impairs the effectiveness of lighting equipment required' by Standard No. 108. Because of moisture accumulation, discoloration, cracks, etc., a glass or plastic cover might tend over a period of time to diminish or distort the headlamp beam. This is of particular concern with reference to the unsealed headlamps implicitly permitted by SAE J584 because of the tendency of the reflector to deteriorate with age.; For the reasons stated above, the agency has concluded that no headlam may have a glass or plastic shield in front of it when in use, regardless of the type of vehicle on which it is used.; As for the turn signals, no part of the vehicle may impair thei visibility through horizontal angles 45 degrees to the right and left of the vehicle (for right and left turn signals respectively) measured at the longitudinal axis of the vehicle. An unobstructed illuminated area of outer lens surface of at least 2 square inches excluding reflex is necessary to meet this requirement. You will have to judge for yourself whether the turn signal requirements are met with your planned cover in place.; If you have any further questions, we shall be happy to answer them. Sincerely, Frank Berndt, Chief Counsel