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Proposed Rule

Denial of Petition for Rulemaking; Federal Motor Vehicle Safety Standards

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National Highway Traffic Safety Administration (NHTSA), Department of Transportation.


Denial of petition for rulemaking.


This document denies the petition submitted by Sierra Products, Inc. (Sierra), to amend Federal Motor Vehicle Safety Standard (FMVSS) No. 108, “Lamps, Reflective Devices, and Associated Equipment,” to allow center high-mounted stop lamps (CHMSLs) to be combined with identification lamps, and to require that identification lamps be lowered to eye height on heavy trucks.

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Mr. Chris Flanigan, Office of Rulemaking, NHTSA, 400 Seventh Street, SW., Washington, DC 20590. Mr. Flanigan's telephone number is: (202) 366-4918. His facsimile number is (202) 366-4329.

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By a letter dated September 19, 2001, Sierra petitioned the agency to amend FMVSS No. 108 to allow vehicles with a width of 2032 millimeters (mm) or greater to have their CHMSLs physically and optically combined with their three identification lamps and that this combination of lamps be required to be lowered to eye height. Sierra found that an industry standard was being changed to allow the combination of these lamps.

Background: FMVSS No. 108 requires CHMSLs to be on all motor vehicles, except trailers and motorcycles, that are less than 2032 mm wide. It does not require CHMSLs on any other vehicle. CHMSLs on vehicles not required to have these lamps are considered by the agency to be auxiliary lamps that are not specifically regulated. Manufacturers may voluntarily install CHMSLs on vehicles on which CHMSLs are not required provided that the voluntary CHMSL does not impair the effectiveness of required lamps.

FMVSS No. 108 requires that identification lamps (a cluster of three lamps) be mounted on the centerline and as high as practicable on vehicles whose overall width is 2032 mm or more. The purpose of identification lamps is to uniquely identify large vehicles and do so with the longest possible sight preview of the lamps.

The industry standard Sierra referred to in its petition is Society of Automotive Engineers (SAE) J1432, “High-Mounted Stop Lamps for Use on Vehicles 2032 mm or More in Overall Width (March 2000).” This standard specifies requirements for CHMSLs on heavy trucks. This standard was amended to allow combination of the CHMSL and three identification lamps. This change to J1432 first appeared in the 2001 version of the “SAE Ground Vehicle Lighting Standards Manual.” To maintain the conspicuity of each signal, J1432 specifies that the CHMSL must emit at least three to five times (depending on lamp position) the amount of light that the identification lamps emit.

Petitioner's Rationale: Sierra believes that, because SAE J1432 has been amended to allow the combination of CHMSLs and identification lamps on heavy trucks, FMVSS No. 108 should be changed as well. It states that if the agency were to amend the standard to allow the combination of the signal lamp configurations and also to require this combination to be moved downward to “eye level,” the CHMSLs would be located in a more effective position. It also believes that this would provide an economic incentive for manufacturers of heavy trucks to include CHMSLs on these vehicles.

Regarding the agency's current requirement that identification lamps be mounted “as high as practicable,” Sierra believes it is outdated. It states that the original reasons for this requirement were for “visually checking a vehicle's height in order to avoid hitting a bridge or overhang” and “for following traffic to spot slow moving trucks cresting steep hills.” Sierra states that, today, neither of these reasons makes sense. It believes that heavy trucks routinely travel as fast as regular traffic and they no longer need identification lamps to visually clear bridges and overhangs. Also, it states that “steep hill crests have been leveled.” No information was supplied by Sierra to support these assertions.

Agency Analysis: The agency believes there are no recommendations in Sierra's petition that would improve motor vehicle safety. Sierra has made a number of assumptions that are not based in fact. The petition references a change made to SAE J1432 that allows combination of the CHMSL and identification lamps on vehicles with a width that is 2032 mm or greater. Sierra further stated that it is aware that the agency has been adamant about not allowing any other lamps to be mounted in the same housing with a CHMSL, and that it was not aware that NHTSA had removed this prohibition. Sierra is confused as to when and how this combination (in the SAE standard) had come to be allowed.

As stated above, the CHMSLs of which Sierra speaks are auxiliary lamps under FMVSS No. 108, and as such, are not specifically regulated for vehicles that are 2032 mm or wider. The only specific criterion applicable to such supplemental stop lamps is that they not impair the effectiveness of any required lamps. Conceptually, auxiliary stop lamps should not impair the effectiveness of the required identification lamps if they perform identically to required stop lamps. One means for assuring this is for the lamps to meet SAE J1432 or the requirements in FMVSS No. 108 that apply to stop lamps. The SAE document, among other things, states that “[t]he purpose of the high-mounted stop lamp or lamps is to provide a signal over intervening vehicles to the driver of following vehicles.” As such, it has the same purpose as the identification lamps in that they, too, are required to be located to provide a preview over intervening vehicles.

Sierra is confused about the CHMSLs required by FMVSS No. 108 and the stop lamps that are described in SAE J1432. While the FMVSS No. 108 CHMSLs, which are required on some vehicles, are prohibited from being combined with any lamp (whether required or auxiliary, except for cargo lamps), the SAE J1432 CHMSLs are not regulated in any manner. Thus, contrary to Sierra's statement, there has never been such a rescission for the CHMSL regulated by FMVSS No. 108. More importantly, there has never been a prohibition on combining supplementary stop lamps with identification lamps.

In fact, this interpretation has been expressly stated in at least three letters issued by the agency to persons asking about such auxiliary stop lamps. The most recent was a June 1999 letter to an anonymous author which stated that:

You have also asked whether this product [a light bar containing three identification lamps] can also incorporate “a set of brake lights to act as a ‘third eye' brake light, similar to those required for automobiles.” In other words, the identification lamp bar would act as a supplementary stop lamp when the brakes are applied.

Standard No. 108 permits supplementary lamps as long as they do not impair the effectiveness of the lighting equipment required by the standard (S5.1.3). The function of the identification lamps is to indicate the presence of a large vehicle in the roadway. This effectiveness of this function would not be impaired by an increase in intensity of the lamps when the brake pedal Start Printed Page 5864is applied. Therefore, your product can incorporate a supplementary stop lamp function.

Sierra argued further that, if acceptable, it would make “economic and safety sense” to allow this signal combination to be used on vehicles with a width of 2032 mm or greater and to be lowered to “eye height.” Sierra's economic argument is that installing a CHMSL separately from the identification lamps costs more. Now that the agency has allowed the combination of supplementary stop lamps and identification lamps, Sierra asserts that the CHMSL must be in the wrong location, thus forcing the installation of a separate lamp anyway. To eliminate the need for an extra lamp, Sierra wants the combination of lamps to be lowered.

In the second part of the petition, Sierra requests that the identification lamps, as well as all signal and marker lamps mounted on the rear, be required to be mounted at eye level. Sierra indicated that “numerous Public and Federally Financed Tests performed prove that the ‘Centered, Eye Level’ Location is where following Drivers focus most of their Conscience and/or Subconscious Attention, and therefore is the most ‘Conspicuous’ and the most effective place to locate all rear Signal Vehicle Lights, except ‘Clearance’ Lights * * * which should represent ‘Extreme Width’ * * * while also located at Eye Level.” However, Sierra provided no specific test data to support its assertions that the aforementioned research is applicable to its suggested amendment.

While putting all lamps at eye level may seem plausible, there is no evidence that this is the most effective location. Sierra did not specify what the height should be. Eye height is different for drivers of sports cars, passenger cars, light duty trucks, large trucks, and buses. Also, a significant reason for higher mounting heights for lamps that provide signals of driver intent (stop and turn lamps) is to inform following drivers, not just the most immediately rearward one, of the vehicle's intent to stop. The agency is not prepared to initiate rulemaking to require CHMSLs on heavy trucks. If identification lamps were lowered, the purpose of uniquely identifying large vehicles with the longest possible sight preview of the lamps would be compromised. As the mounting height of identification lamps is lowered, the time that nearby drivers will have to identify the vehicle, as a heavy truck will lessen. This is contrary to the intent of the requirement.

On the other hand, the mounting height of identification lamps has been long established to be “as high as practicable.” This is to make nearby drivers aware of the vehicle's size. If these lamps were lowered to eye level, approaching drivers may not be able to distinguish large commercial vehicles from passenger vehicles.

Sierra has provided no convincing rationale that Standard No. 108 should be amended in the manner in which it petitioned and, in accordance with 49 CFR part 552, after review of the petition, the agency has concluded that it should not be granted. Accordingly, it denies Sierra's petition.

(49 U.S.C. 30118(d) and 30120(h); delegations of authority at 49 CFR 1.50 and 501.8)

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Issued on: January 30, 2003.

Stephen R. Kratzke,

Associate Administrator for Rulemaking.

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[FR Doc. 03-2700 Filed 2-4-03; 8:45 am]