Interpretation ID: 20333.ztv
Samson Helfgott, Esq.
Helfgott & Karas, P.C.
60th Floor
Empire State Building
New York, NY 10018-6098
Dear Mr. Helfgott:
This is in reply to your letter of July 16, 1999, with reference to modification of a lighting device invented by your client, Harold Caine.
The basic device is an amber lamp which would be mounted adjacent to, and in a separate housing from, the center high-mounted stop lamp. The amber lamp would be activated when the ignition is on, and deactivated when the brakes are applied. On March 30, 1989, we advised you that the lamp did not appear to impair the effectiveness of the center lamp within the meaning of S4.1.3 of Federal Motor Vehicle Safety Standard No. 108 (now S5.1.3) but that you should consider "whether your lamp, since it would be a steady burning amber lamp, might confuse following drivers unused to seeing a steady burning amber lamp on the rear of a vehicle." We further advised that, should the lamp cause confusion, it might impair the effectiveness of the other rear lamps required by Standard No. 108. We did not ourselves reach an impairment conclusion but advised that a manufacturer must take this into consideration in certifying that its vehicle complies with all applicable Federal motor vehicle safety standards including S5.1.3 of Standard No. 108, the prohibition against adding extra lighting equipment that impairs the effectiveness of lighting equipment required by the standard.
You now propose a modification of this running lamp into one that is intended to indicate when the driver "quickly takes his foot off the accelerator" by extinguishing all light sources except those that form an "X" in the lamp. When the brakes are applied, the "X", too, will be extinguished.
In our opinion, the introduction of the "X" into the light provides an additional opportunity to confuse a following driver and dilute the effectiveness of rear signals. Whereas a following driver who sees a steady-burning amber lamp succeeded by a steady burning center red lamp might not hesitate to apply the brakes, there is a greater possibility that a following driver who sees an amber lamp change into an amber "X" and then replaced by the red center lamp will have a slower reaction time to the stop signal when confronted with the unfamiliar "X." Further, the presence of an on and off "X" during operation of the rear turn signals or the back up lamps also contains the potential for confusion.
In summary, we believe that the lamp with the "X" feature would impair the effectiveness of the rear lighting equipment required by Standard No. 108, and that installation of an amber lamp with this feature is prohibited by S5.1.3. You have also asked whether it would make any difference if the "X" were red rather than amber. For the reasons given above, our answer is the same: this feature is also prohibited by S5.1.3.
In our view, traffic safety is enhanced by the familiarity of drivers with established lighting schemes, which facilitates their ability to instantly and unhesitatingly recognize the meaning a lamp conveys and to respond to it. Any modification to the required lamps or any supplemental lamp that could be perceived to have signals different from the required functions when these functions are operating, or could be perceived incorrectly as signals from required functions would be deemed by us to impair the effectiveness of the required lighting.
If you have any questions, you may call Taylor Vinson of this Office (202-366-5263).
Sincerely,
Frank Seales, Jr.
Chief Counsel
cc: Wayne Highley
ref:108
d.8/19/99