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NHTSA Interpretation File Search

Overview

NHTSA's Chief Counsel interprets the statutes that the agency administers and the standards and regulations that it issues. Members of the public may submit requests for interpretation, and the Chief Counsel will respond with a letter of interpretation. These interpretation letters look at the particular facts presented in the question and explain the agency’s opinion on how the law applies given those facts. These letters of interpretation are guidance documents. They do not have the force and effect of law and are not meant to bind the public in any way. They are intended only to provide information to the public regarding existing requirements under the law or agency policies. 

Understanding NHTSA’s Online Interpretation Files

NHTSA makes its letters of interpretation available to the public on this webpage. 

An interpretation letter represents the opinion of the Chief Counsel based on the facts of individual cases at the time the letter was written. While these letters may be helpful in determining how the agency might answer a question that another person has if that question is similar to a previously considered question, do not assume that a prior interpretation will necessarily apply to your situation.

  • Your facts may be sufficiently different from those presented in prior interpretations, such that the agency's answer to you might be different from the answer in the prior interpretation letter;
  • Your situation may be completely new to the agency and not addressed in an existing interpretation letter;
  • The agency's safety standards or regulations may have changed since the prior interpretation letter was written so that the agency's prior interpretation no longer applies; or
  • Some combination of the above, or other, factors.

Searching NHTSA’s Online Interpretation Files

Before beginning a search, it’s important to understand how this online search works. Below we provide some examples of searches you can run. In some cases, the search results may include words similar to what you searched because it utilizes a fuzzy search algorithm.

Single word search

 Example: car
 Result: Any document containing that word.

Multiple word search

 Example: car seat requirements
 Result: Any document containing any of these words.

Connector word search

 Example: car AND seat AND requirements
 Result: Any document containing all of these words.

 Note: Search operators such as AND or OR must be in all capital letters.

Phrase in double quotes

 Example: "headlamp function"
 Result: Any document with that phrase.

Conjunctive search

Example: functionally AND minima
Result: Any document with both of those words.

Wildcard

Example: headl*
Result: Any document with a word beginning with those letters (e.g., headlamp, headlight, headlamps).

Example: no*compl*
Result: Any document beginning with the letters “no” followed by the letters “compl” (e.g., noncompliance, non-complying).

Not

Example: headlamp NOT crash
Result: Any document containing the word “headlamp” and not the word “crash.”

Complex searches

You can combine search operators to write more targeted searches.

Note: The database does not currently support phrase searches with wildcards (e.g., “make* inoperative”). 

Example: Headl* AND (supplement* OR auxiliary OR impair*)
Result: Any document containing words that are variants of “headlamp” (headlamp, headlights, etc.) and also containing a variant of “supplement” (supplement, supplemental, etc.) or “impair” (impair, impairment, etc.) or the word “auxiliary.”

Search Tool

NHTSA's Interpretation Files Search



Displaying 161 - 170 of 177
Interpretations Date

ID: nht89-3.16

Open

TYPE: INTERPRETATION-NHTSA

DATE: OCTOBER 13, 1989

FROM: BILL WALTZ -- WAGNER DIVISION, COOPER INDUSTRIES, INC.

TO: STEPHEN WOOD -- ACTING CHIEF COUNCIL, NHTSA

TITLE: NONE

ATTACHMT: ATTACHED TO LETTER DATED APRIL 8, 1990 TO BILL WALTZ FROM STEPHEN P. WOOD; (A35; STD. 108)

TEXT:

Lectric Limited has asked Wagner to assemble some round glass headlights for them, designed to appear as closely as possible to those produced by Guide Lamp in the 1950's.

All markings and configurations on the original lamps are being reproduced and this creates a problem in complying with "108". The lamps they are interested in are 6012 (7"), 4001 (5 3/4" #1) and 4002 (5 3/4" #2). In accordance with the original marking they will have a "1" or "2" at the top of the lens, not the "2D1", "1C1" and "2C1" now required by NHTSA.

Secondly, the inscription DOT, indicating compliance with existing regulations, will be omitted, since this was obviously riot on the original lamps.

We are asking your permission for those deviations since the lamps will be made to today's photometric standards and will be distributed on a limited basis through antique part dealers. The lamps will be subjected to all the tests currently required of the round headlights.

If there is any problem with this production, please let me know, so that we can try to worK out a solution satisfactory to all parties involved.

ID: 19219.ztv

Open

Ms. Jacqueline Glassman
Senior Staff Counsel
DaimlerChrysler Corporation
1401 H Street, NW CIMS 936-00-00
Suite 700
Washington, DC 20005-2110

Re: Interpretation of S7.8.1(b) of Standard No. 108;

Petition for Decision of Inconsequentiality

Dear Ms. Glassman:

I am responding to your letter of December 3, 1998, asking for an interpretation of S7.8.1(b) of Federal Motor Vehicle Safety Standard No. 108. This question arises in the context of an apparent noncompliance in certain Plymouth and Dodge Neon headlamps, duly reported to us, and which is the subject of an inconsequentiality petition that you have filed with us.

S7.8.1(b) requires motor vehicles manufactured on and after September 1, 1998, to be equipped with headlamps which have a mark or markings that are visible from the front of the headlamp, to identify the optical axis of the headlamp, to assure proper horizontal and vertical alignment for aiming purposes. The choice of the design of the mark or markings is left to the manufacturer. The mark or markings may be on the interior or exterior of the lens or indicated by a mark or central structure on the interior or exterior of the headlamp.

Apparently, your company decided that it failed to comply with S7.8.1(b), and filed a Part 573 report with a petition for a decision that the noncompliance was inconsequential to safety. Afterwards, "agency staff asked the company to consider whether a conspicuous horizontal line that fully crosses the headlamp and from which the optical axis easily may be approximated serves as the marking required by S7.8.1(b)." You have "used that line to approximate the optical axis and has confirmed through appropriate testing that aiming the lamps from that point falls within applicable parameters." You have asked "whether the simple measurement from the conspicuous horizontal line across the front of the headlamp constitutes a mark sufficient to comply with S7.8.1(b)."

The horizontal line across the face of the headlamp, which identifies the optical axis, is a "mark" within the meaning of S7.8.1. This has been confirmed by direct examination of a Neon headlamp by our senior lighting engineer, Rich Van Iderstine, the "agency staff" you referred to. Accordingly, the Neon headlamps are considered to meet the marking requirements of S7.8.1(b), and your inconsequentiality petition is moot.

Sincerely,
Frank Seales, Jr.
Chief Counsel
ref:108
d.1/21/99

1999

ID: 15305.ztv

Open

Mr. Mark A. Evans
Photometric Engineer
Calcoast - ITL Lighting Technology
P.O. Box 8702
Emeryville, CA 94662

Dear Mr. Evans:

This is in reply to your letter of May 16, 1997, to Messrs Van Iderstine and Boyd of this agency. For your future reference, the Office of Chief Counsel has been designated as the Office of the National Highway Traffic Safety Administration responsible for providing legal interpretations of the Federal motor vehicle safety standards.

You ask what components of a headlamp must be included when a corrosion test is conducted on it pursuant to Federal Motor Vehicle Safety Standard No. 108. Specifically you ask whether it is "just the housing lens, reflector and bulb?" Because paragraph S8.4(b) "makes a reference to unfixtured," you also ask whether that implies that "the aim and mounting hardware should be included?" Finally, because the connector is to be attached to the bulb, you ask whether that makes "the bulb compression spring a headlamp component?"

The performance requirements to which paragraph S8.4 relates are set forth in paragraph S7.4(h)(3) (applicable to integral beam headlamps) and paragraph S7.5(i) (applicable to replaceable bulb headlamps). These paragraphs require that, after a corrosion test of a headlamp conducted according to paragraph S8.4, "there shall be no evidence of external or internal corrosion or rust visible without magnification." When a headlamp is tested as provided in paragraph S8.4, it is to be tested "with connector attached to the terminals, unfixtured . . . ." Paragraph S4 defines a headlamp test fixture as a test device "whose mounting hardware and components are those necessary to operate the headlamp as installed" on a motor vehicle.

Since the headlamp is to be tested unfixtured, this means that a test headlamp need not be equipped with mounting hardware and associated components at the time of testing for corrosion resistance. However, all other components of the headlamp would be subject to the corrosion test, including its aiming hardware (if so equipped) and the bulb compression spring, and be required to comply with corrosion resistance requirements specified by Standard No. 108.

If you have further questions, you may refer them to Taylor Vinson of this Office (202-366-5263).

Sincerely,
John Womack
Acting Chief Counsel
ref:108
d.6/24/97

1997

ID: nht90-3.96

Open

TYPE: Interpretation-NHTSA

DATE: September 12, 1990

FROM: Paul Jackson Rice -- Chief Counsel, NHTSA

TO: M. Guy Dorleans -- Manager, Regulatory Affairs Department Division Elairage-France, Valeo

TITLE: None

ATTACHMT: Attached to letter dated 7-19-90 from G. Dorleans to P.J. Rice (OCC 503); Also attached to a study entitled Aiming Concept for Headlamps, Solution 3; Also attached to drawing (graphics omitted)

TEXT:

This is in further reply to the letter you and Monsieur Ravier sent on July 19, 1990, with respect to the acceptability of "Aiming concept for headlamps. Solution 3" under Motor Vehicle Safety Standard No. 108. Ms. DeMeter informed Monsieur Ravier on A ugust 8, 1990, that your request for confidentiality of the drawing enclosed had been granted. You did not make a similar request for treatment of your two-page description of Solution 3, and accordingly we are incorporating it by reference in this lett er, and it will be made a part of all public copies of this interpretation.

Section S7.7.5 of Standard No. 108 states that "When a headlamp system is installed on a motor vehicle, it shall be aimable with either an externally applied aiming device, or on-vehicle headlighting aiming devices installed by the vehicle manufacturer." Section S7.7.5.1 sets forth the requirements for external aiming, and section S7.7.5.2 those for on-vehicle aiming. Solution 3 features a lamp which has three aiming pads on the lens, for use with a mechanical aiming device in accordance with SAE requ irements. However, the lamp also has a movable reflector and various horizontal and vertical aim features that appear to be related to on-vehicle aiming. The horizontal and vertical aiming screws, while having markings of angles similar to that require d for on-vehicle aiming devices, are used exclusively in conjunction with the SAE mechanical aiming device. Therefore, we would consider Solution 3 to be a lamp system intended to be aimable by external means, as provided in section S7.7.5.1.

Since this system departs from the procedure normally used with the SAE mechanical aimers, we commend you in your intent to provide appropriate aiming instructions for such headlighting systems with the vehicles operator's manual, even though it is not r equired by Standard No. 108.

I hope that this is responsive to your question.

ID: 2844o

Open

Oral Interpretation of Standard No. l08:
Optical Combination

Z. Taylor Vinson Senior Staff Attorney

Interpretations Files

Recently a lamp manufacturer phoned to ask whether a replacement lighting device it had developed for installation on trucks and trailers in use would be allowable under Standard No. l08.

The lamp as described is an amber-lensed wrap-around lamp incorporating a clearance lamp to the front and a marker lamp to the side, with one bulb for each function. I replied that the prohibition in S4.4. applicable to clearance lamps forbade their combination only with identification lamps and stop lamps, and that if his combination lamp met photometric and mounting requirements applicable to each function, it appeared to be permissible under Standard No. l08.

# ref:108 d:4/6/88

1988

ID: nht91-4.42

Open

DATE: July 8, 1991

FROM: Ken Hanna -- Lectric Limited Inc.

TO: Richard Van Iderstine -- NHTSA

TITLE: None

ATTACHMT: Attached to letter dated 7-29-91 from Paul Jackson Rice to Ken Hanna (A38; Std. 108)

TEXT:

In reference to our last conversation regarding the manufacturing of sealed beam bulbs for antique cars. As per your suggestion, we are gathering data so that we may submit a comprehensive petition with all pertinent information included requesting reinstatement of SAE J579A.

Since it may take up to two years to reinstate SAE J579A and we are anxious to get our sealed beam headlight project underway, we would like to manufacture bulbs in the interim which meet J579C specifications in terms of candlepower and photometrics. However, since these bulbs will lack various identification nomenclature on the face of the lenses which are required by SAE J579C we would like to market these bulbs with clear identification on the packaging identifying them "for display purposes only and not approved for highway use". I discussed this possibility with you in our last conversation and as I recall you felt that NHTSA had no jurisdiction over products which are not intended for highway use and do not fall under the same regulations and specifications required of products which are intended for highway use.

Please let me know as soon as possible whether or not we will be violating any NHTSA restrictions by manufacturing and marketing these bulbs in this manner.

ID: 13415.ztv

Open

Ms. Ana S. Salcedas
308 N. Forklanding Road
Maple Shade, NJ 08052

Dear Ms. Salcedas:

This responds to the letter that you and Mr. Silva sent us on December 14, 1996. We are sending a copy of our reply to Mr. Silva at his Philadelphia address. You have asked our "assistance in ensuring that the patent [for the Auto Brake Light] meets the requirements for Code 571.108."

The patent application indicates that the Auto Brake Light is a message-sending device that can take several forms. In one application, the center highmounted stop lamp can display the message "STOP". In another form, the left hand stop lamp, the center highmounted stop lamp, and the right hand stop lamp can display, one word to a lamp, the message "SLOW DOWN NOW". We assume that the lower stop lamps could also display the message "SLOW DOWN." The application states that "[o]ptimally, the present invention may be used with retrofitted light assemblies that are attached to a vehicle after its original manufacture."

Under our basic regulatory statute, 49 U.S.C. Chapter 301, a motor vehicle must conform with all applicable Federal motor vehicle safety standards at the time it is sold and delivered to its initial purchaser. This means that, if the vehicle is modified after manufacture and before such sale, it must continue to comply with the Federal safety standards after the modifications. Motor Vehicle Safety Standard No. 108 Lamps, Reflective Devices and Associated Equipment, 49 CFR 571.108, permits the addition of supplementary lighting devices at the time of initial manufacture or before initial sale provided that they do not impair the effectiveness of lighting equipment required as original equipment by Standard No. 108.

As noted above, in one form of your invention, the center highmounted stop lamp can display the word "STOP." Figure 10 of Standard No. 108 establishes minimum candela intensity values that must be met at individual test points on the lamp, or the sum of such test points within zones. If any portion of the word "STOP" obscures the light at any individual test point so that the zone total falls below the minimum sum specified for the zone, that obscuration would create a noncompliance with Standard No. 108, and the retrofitted lamp would not be permissible. In addition, visibility of the center stoplamp signal must not be impaired by any part of the vehicle including the word "STOP" from test points 10U to 5D and from 10L to 10R, unless the lamp is designed to comply with all requirements when the obstruction is considered. If the letters can be arranged so that the lamp continues to comply, as discussed above, we do not believe that the word "STOP" would impair the effectiveness of the center stop lamp.

On the other hand, we believe that the message "SLOW DOWN" or "SLOW DOWN NOW" when placed on the lower stop lamps could create a momentary distraction, which would impair the effectiveness of the stop lamp system when used to signal that the vehicle is stopping. This aspect of your invention would not be permitted by Standard No. 108.

Once a motor vehicle is sold, 49 U.S.C. Chapter 301 prohibits manufacturers, dealers, distributors, and motor vehicle repair businesses from making inoperative any device or element of design installed in accordance with a Federal motor vehicle safety standard. We view the phrase "making inoperative" in this case as the equivalent of creating a noncompliance with Standard No. 108. This means that the persons named in the previous sentence may not retrofit a center lamp with the word "STOP" if it obscures any of the required test points. Further, it means that such persons may not retrofit vehicles with lamps spelling "SLOW DOWN NOW."

Because existing lamps are designed to meet the required test points with an unobscured lens, it is almost a certainty that lamps on vehicles in use would become noncomplying if retrofitted with letters forming words such as "STOP" and "SLOW DOWN NOW."

You will note that the prohibition discussed above does not extend to the vehicle owner who, under the statute, may create a noncompliance in his or her vehicle without violating Federal law. But a vehicle modified by its owner remains subject to the laws of the States in which it is registered and used. We are unable to advise you on State laws that may affect your device, and recommend that you contact the Department of Motor Vehicles of the States where you intend to market it.

We offer no opinion on the validity under Federal law of the other patented lighting devices discussed in the application.

If you have any questions, you may contact Taylor Vinson of this Office (202-366-5263).

Sincerely,

John Womack
Acting Chief Counsel

cc: Mr. Armenio N. Silva
     5110 Arendele Ave.
     Philadelphia, PA 19114

ref:108
d:2/25/97

1997

ID: 21871.ztv

Open



    Mr. Thomas C. Bliss
    3M Traffic Control Materials Division
    3M Center
    St. Paul, MN 55144-1000



    Dear Mr. Bliss:

    This is in reply to your letter of June 30, 2000, asking for interpretations of S5.7, Retroreflective Sheeting, of Federal Motor Vehicle Safety Standard No. 108, Lamps, Reflective Devices, and Associated Equipment.

    Several of your customers would like "to incorporate their company logo directly into the conspicuity markings used on their vehicles." You understand that "our customer is permitted to use their logo on markings placed on the vehicle in excess of the amount required to satisfy the minimum coverage stated in the regulation," and you ask that we confirm that interpretation.

    S5.7.1.4.2(a) requires that a strip of retroreflective sheeting, "originating and terminating as close to the front and rear as practicable," be applied to the side of trailers, but that "the strip need not be continuous as long as not less than half of the length of the trailer is covered. . . ." This exception is intended to accommodate different trailer configurations by allowing breaks in the conspicuity material where the features of the trailer are such that it may not be feasible to install continuous sheeting. A manufacturer must comply when half the trailer length is covered, but if it wishes to add more conspicuity material to the portion of the trailer length that is not covered, the material must comply with S5.7. We view the installation of nonconforming material on the side as subject to the prohibition in S5.1.3 that no additional reflective material or other motor vehicle equipment shall be added that impairs the effectiveness of lighting equipment required by the standard. For this reason, the appropriate question is, as you have asked in your first question, "do conspicuity markings that incorporate a logo conform to FMVSS 108?"

    First, because the standard requires conspicuity markings to be either red or white, the introduction of a third color (or white on a red section and vice versa) would not conform to Standard No. 108. Thus, any logo must be red or white. Assuming the logo is red or white, the answer is similar to that which we have provided inquirers as to whether logos are acceptable on the lens of the center high-mounted stop lamp. Both the lamp and retroreflective sheeting must meet the color and photometric requirements that are specified for each. If the sheeting meets the color, photometric, and all other requirements with the logo in place, then retroreflective sheeting incorporating a logo would comply with Standard No. 108. This, of course, would permit a logo that straddles red and white segments of retroreflective sheeting as well as a logo that is contained entirely within either a red or white segment. However, because the standard requires segments of red and white, a red logo could not appear in a white segment and vice versa. A logo (or portion of a logo) in a red segment could, however, be shown in a different shade of red, and a logo (or portion) in a white segment could be shown in a different shade of white, provided that both shades of red and both shades of white complied with the red and white color specifications of SAE J578c.

    Your next question is whether conspicuity markings that incorporate a logo would "qualify as conspicuity markings under FMVSS 108." S5.7 prescribes dimensions for the width of the sheeting and the length of the individual segments. As noted above, a logo could be inserted in otherwise conforming sheeting if the sheeting meets the photometric, color, and all other requirements with the logo in place.

    You have also asked whether "conspicuity markings that incorporate a logo [are] taken into account when assessing conformance to FMVSS standard 108." The coefficients for retroreflection of each segment of red and white sheeting must be not less than the minimum values specified in Fig. 29 of Standard No. 108. In determining conformance with S5.7, if a logo prevented a segment of sheeting from complying with the photometric or any other requirement, we would consider that the segment failed to comply with Standard No. 108. Thus, the answer to this question is yes.

    Finally, you have asked whether "a 48mm (2 inch) wide marking with a logo [which] conforms to the performance requirements necessary for DOT -C2, can . . . be considered DOT-C2 marking." The answer is no. S5.7.1.3(d) requires DOT -C2 sheeting to have a width of not less than 50mm. The sheeting in your question is 2mm too narrow to be DOT-C2, even if it meets the photometric requirements for DOT -C2 sheeting with the logo in place.

    If you have any questions, you may call Taylor Vinson of this Office (202-366-5263).



    Sincerely,

    Frank Seales, Jr.
    Chief Counsel

    ref:108
    d.10/6/00



2000

ID: 1984-2.2

Open

TYPE: INTERPRETATION-NHTSA

DATE: 05/21/84

FROM: AUTHOR UNAVAILABLE; Frank Berndt; NHTSA

TO: Hella North America Inc. -- Walter A. Genthe

TITLE: FMVSS INTERPRETATION

TEXT:

January 23, 1984

Dear Mr. Berndt:

Westfaelische Metall Industrie KG is currently designing headlamps for several automobile manufacturers.

These headlamps are designed to comply with Safety Standards 108 as amended by Docket 81-11 (latest issue: Notice 7).

Preliminary requests by our customers mandate an inclusion of parking/front position lamps and/or turn signal lamps and/or side marker lamps in the overall headlamp design.

A standard U.S. light bulb, meeting FMVSS 108 and/or applicable SAE recommended practices, will be used for these respective functions.

We intend to incorporate these functions into the headlamp compartment, retaining the bulb in question by means of a sealed attachment, similar to the one used in the C6 capsule installation.

No degradation of the system will result, since both functions are contained in one sealed compartment, covered by one common lens. No impairment of the effectiveness of the headlamp function is anticipated, nor will the headlamp impair the function of the parking/position/side marker lamp.

All photometric and environmental specifications for such lamps will be met and no component will be used which is outside the scope of FMVSS 108.

To clarify our intent, a sketch showing the principal design has been enclosed.

We are requesting a statement concerning the agency's opinion in this matter; specifically, as it concerns the legality of the proposed system, whole or in part, and solicit any suggestions as to necessary changes should the system not be in compliance with FMVSS 108, as amended by Docket 81-11.

This matter is of considerable urgency, because of design and manufacturing lead times.

A reply at yyor early convenience coud therefore be appreciated.

Very truly yours,

HELLA NORTH AMERICA INC.

Walter A. Genthe President

WAG/1h

Encls.

cc: Dr. Ernst, K 1 Mr. Westermann, K 1 Mr. Fikus, AF

Insert artwork here.

MAY 21, 1984

Mr. Walter A. Genthe President Hello North America, Inc. P.O. Box 499 Flora, Illinois 62839

Dear Mr. Genthe:

This is in reply to your letter of January 23, 1984, with respect to the inclusion of other lighting functions in a replaceable bulb headlamp compartment. These functions could include parking lamps, turn signal lamps, or side marker lamps. The bulb used would meet Standard No. 108/SAE specifications for the function chosen and they would be incorporated into the compartment bya a "sealed attachment." You represent that there will be no impairment of any function, and that the overall assembly will meet all photometric and environmental specifications. You have asked whether such a combination assembly is permissible under Standard No. 108.

The agency interprets Standard No. 108's specifications for replaceable bulb headlamps as allowing only one bulb in a lamp assembly to be used for headlighting purposes. It is silent as to whether additional bulbs may be used to provide other lighting functions. This means that such a bulb is permitted.

Obviously the inclusion of a second bulb can affect the characteristics of the assembly, whether through heat build up, the introduction of contaminants through the junction of the bulb and assembly, etc. These problems would appear to be minimized under the assumptions set forth in your letter. We believe therefore that, under these conditions, an auxiliary bulb could be included in the headlighting compartment, provided that the assembly meets all applicable requirements of Standard No. 108 for each function. Problems that may develop in service would be subject to the safety related defects authority of the National Traffic and Motor Vehicle Safety Act.

If Hella proceeds with a multi-bulb, design, we would like to request that it share with us the types of tests it will be developing which it deems necessary to insure adequate safety performance, so that our knowledge of state of the art lamp technology may be broadened.

Sincerely,

Frank Berndt Chief Counsel

C6/C6 **INSERT GRAPH**

**INSERT GRAPH**

ID: 1983-2.5

Open

TYPE: INTERPRETATION-NHTSA

DATE: 05/11/83

FROM: AUTHOR UNAVAILABLE; Frank Berndt; NHTSA

TO: Truck-Lite Co. Inc. -- John E. Bennett, Director, Research & Engineering

TITLE: FMVSS INTERPRETATION

TEXT:

Mr. John E. Bennett Director - Research & Engineering Truck-Lite Co., Inc. 310 East Elmwood Avenue Falconer, New York 14733

Dear Mr. Bennett:

This in response to your letter of April 12, 1983, asking for interpretation of paragraph S4.6(b) of Motor Vehicle Safety Standard No. 108.

This paragraph states in pertinent part that "means may be provided to flask...side marker lamps for signalling purposes." You have first asked whether the rear side marker can be made to flash. You have also asked whether this language may be interpreted as allowing both front and rear side marker lamps to be flashed. The answer to both questions is yes. In the absence of restrictive language, paragraph S4.6 may be interpreted as allowing flashing of either front or rear side marker lamps, or both sets of lamps.

You have also asked whether, where the rear side marker and taillamp used the same optical source ("minor filament of a 1157 or similar bulb"), it is acceptable to have an overriding signal lamp is actuated. The answer is yes. The standard's prohibition against optical combinations (paragraph S4.1.1) does not preclude this design.

We hope that this answers you questions.

Sincerely,

Frank Berndt Chief Counsel

April 12, 1983

Attention: Office of Chief Counsel (Room 5219)

Subject: Request for interpretation of an element of FMVSS-108

Dear Sir:

In our endeavor to continue the advancements of vehicle lighting devices, which is a continuing assignment within our company, and offer specialized products to our customers with inherent benefits to the consumers, we have under consideration a new product which requires an interpretation of Section S4.6 Item (b), FMVSS-108, before we finalize our programs.

This section (S4.6) of FMVSS-108 requires.. "when activated:

a. Turn signal lamps, hazard warning signal lamps, and school bus warning lamps shall flash; and b. All other lamps shall be steady burning, except that means may be provided to flash headlamps and side marker lamps for signalling purposes."

Our questions are in reference to the rear side marker lamp and item (b) above. They are stated as follows:

a. Can the rear side marker be made to flash? Is Section S4.6, Item (b) to be interpreted as both front and rear side marker lamps may be flashed for signalling purposes? We know of only one current production (Jeep CJ) vehicle which the rear side marker lamp might be so viewed.

b. In a design where the rear side marker function and the rear tail lamp use the same optical source (minor filament of a 1157 or similar bulb), is it acceptable to have an overriding-flashing signal visible through the rear side marker lens when the signal lamp is actuated?

We are attempting to market a new product within the near future and do not wish to proceed until the above is cleared. Therefore we would appreciate your response to your questions as soon as possible.

Kindly accept our thanks for your prompt attention to this request. Do not hesitate to contact me if I can be of additional assistance.

Sincerely,

TRUCK-LITE CO., INC.

John E. Bennett Director - Research & Engineering JEB:h cc: R. Kotsi

Request an Interpretation

You may email your request to Interpretations.NHTSA@dot.gov or send your request in hard copy to:

The Chief Counsel
National Highway Traffic Safety Administration, W41-326
U.S. Department of Transportation
1200 New Jersey Avenue SE
Washington, DC 20590

If you want to talk to someone at NHTSA about what a request for interpretation should include, call the Office of the Chief Counsel at 202-366-2992.

Please note that NHTSA’s response will be made available in this online database, and that the incoming interpretation request may also be made publicly available.

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