Mr. Derek Yuen
    Xtest, Inc.
    16035 Caputo Drive, Suite A
    Morgan Hill, CA  95037

    Dear Mr. Yuen:

    This responds to your recent e-mail to the National Highway Traffic Safety Administration (NHTSA), in which you seek clarification regarding the requirements of Federal Motor Vehicle Safety Standard (FMVSS) No. 108, Lamps, Reflective Devices, and Associated Equipment, pertaining to motorcycle headlamps. Specifically, you asked whether a motorcycle (or a three-wheeled vehicle with two wheels at the front) may be equipped with a four-headlamp system (with two lower beams and two upper beams), and if so, whether it would be permissible to place one set of lamps (either the lower beams or upper beams) closer to the outer edge of the vehicle, provided that the other two lamps are within 200 mm of each other. As discussed below, FMVSS No. 108 does not permit a motorcycle headlamp system composed of more than two headlamps, so we need not consider the additional issue of spacing of a second pair of headlamps.

    By way of background, NHTSA is authorized to issue Federal motor vehicle safety standards that set performance requirements for new motor vehicles and items of motor vehicle equipment. As an initial matter, you are correct in that the three-wheeled vehicle mentioned in your letter would be considered a "motorcycle" under our regulations. Under 49 CFR 571.3, "motorcycle" is defined as "a motor vehicle with motive power having a seat or saddle for the use of the rider and designed to travel on not more than three wheels in contract with the ground".

    The requirements for motor vehicle lighting are contained in FMVSS No. 108, with the headlighting requirements for motorcycles set forth in S7.9, Motorcycles. In particular, paragraph S7.9.6 requires that a headlighting system be located on the front of the motorcycle and, most pertinent to your proposed design, be installed in accordance with the requirements of S7.9.6.2. The requirements of S7.9.6.2 are as follows:

      (a)  If the system consists of a single headlamp, it shall be mounted on the vertical centerline of the motorcycle….

      (b)    If the system consists of two headlamps, each of which provides both an upper and lower beam, the headlamps shall be mounted either at the same height and symmetrically disposed about the vertical centerline or mounted on the vertical centerline….

      (c)     If the system consists of two headlamps, one of which provides an upper beam and one of which provides the lower beam, the headlamps shall be located on the vertical centerline with the upper beam no higher than the lower beam, or horizontally disposed about the vertical centerline and mounted at the same height….

    Because the system your letter envisions consists of four headlamps, it would not meet the requirements of S7.9.6.2 of FMVSS No. 108. (We note further that the Japan Auto Parts Industries Association submitted a petition for rulemaking in 1998, which included a request to amend FMVSS No. 108 to allow four distinct headlamps on motorcycles, but the agency decided not to do so (see 69 FR 55993 (Sept. 17, 2004). ) Because such a system is not permitted under Standard No. 108, we need not analyze this system in terms of the motorcycle headlamp location requirements contained in paragraph S7.9.6 of the standard.

    If you have further questions, please feel free to contact Eric Stas of my staff at this address or by telephone at (202) 366-2992.


    Stephen P. Wood
    Acting Chief Counsel