The Honorable Orrin G. Hatch
United States Senate
Washington, DC 20510-4402

Dear Senator Hatch:

Thank you for your letter of June 4, 1999, requesting our advice on "existing law regarding motor vehicle lighting and how that law affects a recent invention," which is described as an "enhanced motor vehicle warning system" ("the System").

Our agency, the National Highway Traffic Safety Administration (NHTSA), has been authorized by Congress to issue Federal motor vehicle safety standards. One of these standards prescribes performance requirements for both original and replacement motor vehicle lighting equipment, 49 CFR 571.108, Standard No. 108, Lamps, Reflective Devices, and Associated Equipment. Standard No. 108 requires motor vehicles to be manufactured in accordance with its requirements and prohibitions.

The System works as follows. When a vehicle's horn is sounded, the System also flashes the vehicle's headlamp upper beams and its backup lamp or lamps. As you point out, paragraph S5.5.10(b) of Standard No. 108 allows the headlamps to be wired to flash for signaling purposes. However, as you also point out, S5.5.10(d) states that all other lamps shall be steady burning, and you conclude that the System would appear to violate this clause. You have asked for "an official interpretation of the rule to determine if the rear lamps, when connected to this device, would violate (d)."

Your interpretation is correct; S5.5.10(d) does not allow the backup lamp or lamps to flash when in use, and the System is not permissible because it flashes the backup lamps.

S5.5.10(a) specifies that hazard warning system lamps be wired to flash. One of your staff members discussed with us whether the System would be allowable were it modified to operate through the hazard warning system, which flashes in normal operation when activated by the driver, rather than through the backup lamps, which do not flash in use. The acceptability of such a

Standard No. 108. This paragraph prohibits the installation of additional equipment on a vehicle if it would "impair the effectiveness" of lighting equipment required by the standard. In recent years, we have come to the conclusion that use of required lighting equipment for other than its original purpose may compromise and reduce its safety effectiveness. As we said in 1996,

It is important that the integrity of the required signal lamps be maintained, and that auxiliary signal lamps not detract attention from the messages that the required signal lamps are sending. A vehicle signaling system must be as simple and as unambiguous as possible to others who share the roadway if traffic is to proceed in a safe and orderly fashion. (61 FR 65516)

We believe that a hazard warning system should not be used for the auxiliary purpose of providing an optical warning when the horn is sounded, since such a warning bears no relationship to the original purpose of a hazard warning signal and thus could create confusion about the meaning of the hazard warning signal. For this reason, we conclude that S5.1.3 would prohibit the optical warning system you describe even if it were modified to operate through the hazard warning system lamps.

In the event that the System is precluded by Standard No. 108, you have asked about our procedure for petitioning for rulemaking to amend Standard No. 108. These procedures are set forth in 49 CFR 552.4. The petition must contain the name and address of the petitioner and be addressed to the NHTSA Administrator. It must be in the English language, prefaced by the word "Petition," set forth facts in support of an amendment, and contain a brief description of the substance of the requested amendment. We are required to inform the petitioner within 120 days whether the petition is granted or denied. If the petition is granted, action on it may not be immediate as the petition must take its place among other rulemaking priorities.

Petitioners for changes in signaling lamp requirements should become familiar with the policy statement we issued in 1998 discussing how we evaluate rulemaking petitions to require or permit new or different signal lighting or signal lighting actuation (63 FR 59842). I enclose a copy for your information.

You also express your understanding that "NHTSA can issue a letter stating that Standard 108 does not preclude the use of this device in new vehicles, thereby allowing this invention to be installed on new cars." We do provide interpretive letters of this nature when a product does not conflict with the requirements and prohibitions of Standard No. 108. For the reasons indicated above, we cannot provide such a letter for this System.

Although a copy of the patent of the device and related application data did not accompany your letter, we did not need this information for purposes of this interpretation. If your staff has further questions, they may call Taylor Vinson of this Office (202-366-5263), the attorney who has previously spoken with your office on this subject.

Frank Seales, Jr.
Chief Counsel