Interpretation ID: nht79-4.32

DATE: 07/31/79

FROM: AUTHOR UNAVAILABLE; F. Berndt; NHTSA

TO: Yamaha Motor Corporation U.S.A.

TITLE: FMVSS INTERPRETATION

TEXT: This is in reply to your letter of July 2, 1979, to our former Chief Counsel, Joseph Levin asking for an interpretation of Federal Motor Vehicle Safety Standard No. 108.

You have quoted Column 3 of Table IV with respect to motor cycle headlamps and the specification that the one headlamp the standard requires be located "on the vertical centerline, except that if two are used they shall be symmetrically disposed about the vertical centerline". Yamaha would like to equip certain motor cycles with two headlamps, one to be mounted above the other on the vertical centerline with the hope that "this may increase conspicuity and facilitate safety". You have asked whether this mounting arrangement conforms with Standard No. 108.

The arrangement you have in mind is not permitted by the Federal lighting standard. "Symmetrically disposed about the vertical centerline" means that each headlamp is an equal distance from the vertical centerline at the same horizontal location. We believe that this provides better and more evenly distributed forward illumination than the system Yamaha proposes, while being the equivalent in conspicuity.

SINCERELY,

YAMAHA MOTOR CORPORATION U.S.A.

July 2, 1979

Joseph J. Levin Chief Counsel National Highway Traffic Safety Administration

Dear Mr. Levin:

Yamaha is exploring the possibility of utilizing two headlamps on some of our motorcycle models. We believe this may increase conspicuity and facilitate safety. Our question deals with the location of the headlamps pursuant to FMVSS 108.

We would like to place the headlamps on the vertical centerline of the vehicle, one above the other. Column 3 of Table IV of FMVSS 108 states: "on the vertical centerline, except that if two are used they shall be symmetrically disposed about the vertical centerline."

This section, we believe, can be interpreted to allow the placement of dual headlamps in two ways. The lamps may be placed on the vertical centerline, one above the other, or they may be located horizontally so long as they are equal distance from the vertical centerline.

We would deeply appreciate your concurrence with this interpretation or an explanation of permissible locations. Thank you for your consideration in this matter.

Michael J. Schmitt Legal Counsel Engineering Division