Legal & Homologation Service
Stanley Electric Col, Ltd2-9-13, Nakameguro, Meguro-ku
Tokyo 153, Japan
Dear Mr. Suzuki:
This is in reply to your letter of March 10, 1997, asking for interpretations of Federal Motor Vehicle Safety Standard No. 108 with respect to the effective projected luminous area of stop lamps and turn signal lamps.
Paragraph S18.104.22.168 states that "[e]ach turn signal lamp on a motorcycle manufactured on and after January 1, 1973, shall have an effective projected luminous area of not less than 3 1/2 square inches." Your interpretation is "Turn signal lamp on a motorcycle shall have an effective projected luminous area of not less than 3 1/2 square inches." (S22.214.171.124). Your understanding of this requirement is correct.
Section 5.3.2 of SAE J586 FEB84 Stop Lamps For Use on Motor Vehicles Less than 2032MM in Overall Width, specifies that "the functional lighted lens area of a single compartment lamp shall be at least 37.5 square centimeters." Your interpretation is that the "stop lamp on a motorcycle shall have an effective projected luminous area of not less than 37.5 square centimeters (SAE J586 FEB84)." This is not correct. Although SAE J586 FEB84 has been incorporated by reference into Standard No. 108 by paragraph S5.1.1, section 5.3.2 of SAE J586 FEB84 does not apply. Paragraph S5.1.1 allows exceptions to SAE J586 FEB84, and the applicable provisions for motorcycle stop lamps are set forth in two paragraphs under S5.1.1: paragraphs S126.96.36.199 and paragraph S188.8.131.52(a).
Under these two paragraphs, if a motorcycle is a motor driven cycle (i.e., one with an engine developing 5 brake horsepower or less) and if its speed attainable in 1 mile is 30 mph or less, it may be equipped with a stop lamp whose effective projected luminous lens area is not less than 3 1/2 square inches (S184.108.40.206). Otherwise, a motorcycle must be equipped with at least one single compartment stop lamp whose functional lighted lens area is not less than 50 square centimeters. The terms "effective projected luminous lens area," "effective projected luminous area," and "functional lighted lens area" are used interchangeably in Standard No. 108.
You also ask for confirmation that "[t]he functional lighted lens area of a single compartment stop lamp, and a single compartment rear turn signal lamp on a motor vehicle (other than motorcycle) whose overall width is less than 80 inches, shall be not less than 50 square centimeters. (S220.127.116.11)." This is correct, except that paragraph S18.104.22.168(a) applies to motorcycles as well as to other vehicles.
If you have any further questions about this letter, you may refer them to Taylor Vinson of this Office (FAX 202-366-3820).
Acting Chief Counsel