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Interpretation ID: 6918

Mr. William H. Spain
Touch Wood
5417 Caldwell Mill Road
Birmingham, AL 35242

Dear Mr. Spain:

This responds to your letter of January 21, 1992, to Taylor Vinson of this office, with reference to your "Auxiliary Lighting Device". I understand that you have also discussed the Device on the phone with Mr. Vinson on March 3, and with Mr. Van Iderstine of the Office of Rulemaking on March 26. You have referenced sections S5.1.3, S5.1.1.11, S5.3.1.1, S5.5.3 and S5.5.10(a) of Motor Vehicle Safety Standard No. 108, and ask for an "initial first impression as to whether or not we might have a problem."

In your experience, "it is not an uncommon occurrence for a tractor/trailer to lose its taillamps due to a circuit or wiring malfunction." When this occurs, you point out that the driver's only choice is to activate his hazard warning system, which is not its intended purpose, and which defeats the normal turn signal circuits. Your Device would permit the operator of the tractor to employ the rear turn signal lamps as surrogate taillamps if the vehicle's standard taillamps were inoperative. Specifically, "a reduced voltage is fed through both right and left rear turn signal circuits to cause both turn signal lamps to illuminate at a reduced brilliance equal to that of a normal tail lamp." The Device has an alternative function. It permits the turn signal lamps to be used at full intensity as fog lamps to increase rear visibility. The activation of the turn signal switch within 1/2 second overrides the Device and allows normal operation of the turn signal lamps. The Device is activated through a toggle switch on the dash, which glows to indicate to the driver that it is engaged.

The applicability of the National Traffic and Motor Vehicle Safety Act of 1966 (the "Act") and Motor Vehicle Safety Standard No. 108 to tractor-trailer combinations is not well defined. Standard No. 108 is, in essence, a manufacturing standard that applies to individual motor vehicles. It ceases to apply at the time of purchase by its first owner (other than the manufacturer or dealer). Once a vehicle is sold, questions of continued compliance with the standards, including Standard No. 108, must be answered with reference to the Act. The question presented by your letter concerns a device added to one vehicle before its first sale that is intended to affect the lighting performance on another vehicle after the sale of the second vehicle (i.e., when it has become a "vehicle in use", to use the statutory term). We recently provided another interpretation of the applicability of Standard No. 108 and the Act to towing and towed vehicle combinations which I would like to discuss, as it provides a basis for our interpretation to you, but is nevertheless distinguishable from it by its facts (letter of April 3, 1992, to Echlin Corp.)

The Echlin Corp. device (the "Control") was intended to control trailer sway by allowing the towing vehicle's driver to apply the towed vehicle's brakes through modulated pressure by use of a hand control in the towing vehicle. The wiring of the Control was such that the trailer stop lamps were not activated when the Control was in use. Standard No. 108 and the laws of some States require that the stop lamps be activated when the service brakes are applied. We informed the manufacturer of the Control that, under the specific facts of the case, the question was not one to be answered under Standard No. 108 as applying to new vehicles, but to be answered under the Act as it affects vehicles in use. The Act contains a general prohibition (l5 U.S.C. 1397(a)(2)(A)) against knowingly rendering inoperative, in whole or in part, any device or element of design on a vehicle in use that has been installed in accordance with a Federal motor vehicle safety standard. The prohibition applies to any manufacturer, dealer, distributor, or motor vehicle repair business. With respect to the Control, the dealer of the towed vehicle adds the Control to the towing vehicle (a vehicle in use) at the time that the towed vehicle is purchased. In our opinion, the legal question was whether the dealer of the towed vehicle had rendered the stop lamps of the towed vehicle partially inoperative by its installation of the Control on the towed vehicle. In our opinion, it was not the installation of the Control but its use that was critical. The user of the Control, the vehicle operator, is not covered by the prohibition. Therefore, we informed Echlin that the sale and use of the Control does not violate the Act.

This interpretation can also be viewed as stating that "inoperability" as the word is used in the statute must result from a direct act, and not an indirect one. This, however, was not our intent. We do not believe that a person should be excused from responsibility simply because an intervening agency is required to operate a device that that person has manufactured or sold. Although many of the facts concerning the use of the Control and your Device are similar, the fact of importance in this instance is the primary purpose of the equipment in question. The primary purpose of the Control was to control trailer sway, not to affect the operation of the stop lamps. The primary purpose of your Device is to affect vehicle lighting, by serving as surrogate and supplementary lighting equipment.

A further fact in difference is that you envision the Device to be installed as part of the manufacture of the tractor trailer, and not added by the dealer of the trailer to a tractor trailer in use. This raises the question of the certification that the Act requires by the truck tractor manufacturer of compliance with Standard No. 108, specifically S5.1.3. As your letter indicates, you are aware that S5.1.3 prohibits the installation of additional lamps or reflectors "or other motor vehicle equipment that impairs the effectiveness of lighting equipment required by" Standard No. 108. It is manifest that installation of the Device has no effect upon the lighting equipment of the vehicle on which it is installed, the truck tractor. The question is whether S5.1.3 can be read as prohibiting the installation of a device on one vehicle that may affect the operation of lighting equipment on another vehicle.

We believe that S5.1.3. can be so read because the term "lighting equipment required by" Standard No. 108 is general in nature, and not restricted to the vehicle on which the additional equipment is installed. Although Standard No. 108 does not establish lighting requirements to be met by combinations of towing and towed vehicles, we interpret S5.1.3 as prohibiting installation of any original equipment on the towing vehicle that could impair the effectiveness of the lighting equipment required by Standard No. 108 to be installed on a towed vehicle. The determination of whether impairment exists is initially made by the manufacturer in certifying compliance of the towing vehicle to all applicable Federal motor vehicle safety standards. If a manufacturer installs as original equipment on one motor vehicle a device whose sole purpose is to affect the lighting performance of another motor vehicle, then that manufacturer must take into account whether that device would impair the effectiveness of the other vehicle's lighting equipment in certifying compliance to S5.1.3. If that decision appears clearly erroneous, NHTSA may make its own determination in order to effect compliance with Standard No. 108.

We turn first to the question of the use of the Device as a surrogate taillamp on a vehicle equipped with red rear turn signal lamps. When used as a taillamp surrogate, the Device would substitute one steady-burning red rear light for another. If, as you indicate, the intensity of the surrogate taillamp is no greater than that of the original taillamp (and thereby maintains the ratio of difference required in combination turn signal- taillamps), there would appear to be no impairment of rear lighting equipment.

When used as a fog lamp on a vehicle equipped with red rear turn signal lamps, the taillamps are not disabled, and the Device activates the turn signal lamps at full intensity in a steady burning mode. Commonly, combination rear lamps on large vehicles also include the stop function as well. Because of the similarity of intensity between the steady burning fog lamp and the stop function provided by the same filament, or the stop function in an adjacent lamp, we believe that the stop signal would be impaired when the Device is used as a fog lamp in a lamp configured as described in this paragraph.

When used on a trailer equipped with the amber turn signal lamps that Standard No. 108 permits, different considerations apply. All lamps that serve as marker lamps on the rear (taillamps, identification lamps, clearance lamps) are required by Standard No. 108 to be red in color. On a trailer equipped with amber rear turn signals, the use of your Device would result in a pair of steady burning amber marker lamps on the trailer rear where, heretofore, the motoring public has not been accustomed to seeing them. Thus, the question arises under S5.1.3 whether the effectiveness of the required red rear lighting equipment is impaired when the Device activates steady burning amber rear lamps.

You are aware of this possibility, but have pointed out to Mr. Vinson that the Device is intended for use when the taillamps are not available. Because taillamps, identification lamps, and clearance lamps share the same wiring, inoperability of the taillamps often means inoperability of the other rear marker lights. Thus, the steady burning amber lamps provided by the Device may be the only operating marker lamps on the rear of the vehicle. You believe that this is preferable to no lights at all. We would agree that, in this circumstance, there would be no impairment of required rear lighting equipment within the meaning of S5.1.3.

However, the Device provides no safeguards against operation of the amber turn signal lamps in the taillamp mode when the taillamps (and other rear marker lamps) remain operative. Further, it permits operation of the amber turn signal lamps in the fog lamp mode regardless of the operability of the other rear marker lamps. Because the Device is intended for use only under conditions of reduced visibility, such as night and fog, when the headlamps are activated, there is a potential for confusion when a motorist is confronted with simultaneously operating steady burning red and amber lamps. In this situation, a conclusion could be drawn that the utilization of the Device to create a steady burning amber lamp could, within the meaning of S5.1.3, impair the effectiveness of the lighting equipment that is required to be red. You told Mr. Vinson of your willingness to provide a warning with the Device cautioning against its use when the taillamps are operative, and we appreciate your concern with the issue. You may wish to reexamine the efficacy of amber lamps as fog lamps. We understand that the most effective rear fog lamps are red, and that red is the only color permitted in Europe.

You pointed out in your letter that, absent the Device, the tractor operator might choose to employ the flashing hazard warning lights for other than their intended purpose. We believe that today's motorists interpret flashing red or amber hazard lamps on moving vehicles as a signal that the vehicle is moving slower than the stream of traffic, and that caution is advised. Thus, safety may be enhanced when the hazard lamps flash, as they provide a contrast with the steady burning but less intense red rear taillamps.

Finally, even if acceptable under the regulations and statutes administered by this agency, vehicles engaged in the commercial aspects of interstate commerce are subject to the regulations of the Office of Motor Carrier Standards (OMCS) Federal Highway Administration, and to the regulations of the individual States where the trailer is operated. We are not able to advise you of their restrictions, if any. You may write the Director, OMCS, Room 3404, 400 Seventh Street, S.W., Washington, D.C. 20590 for an interpretation. The American Association of Motor Vehicle Administrators, 4600 Wilson Boulevard, Arlington, Va. 22203, may be able to provide you with an interpretation of State laws. Sincerely,

Paul Jackson Rice Chief Counsel ref:108 d:4/27/92