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
| Interpretations | Date |
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ID: nht79-4.45OpenDATE: 01/11/79 FROM: AUTHOR UNAVAILABLE; Joseph J. Levin, Jr.; NHSTA TO: Grumman Flxible TITLE: FMVSS INTERPRETATION TEXT: U.S. DEPARTMENT OF TRANSPORTATION NATIONAL HIGHWAY TRAFFIC SAFETY ADMINISTRATION WASHINGTON, D.C. 20590 JAN 11 1979 NOA-30 Mr. R. L. Ratz, P.E. Product Safety Engineering Grumman Flxible 970 Pittsburgh Drive Delaware, Ohio 43015 Dear Mr. Ratz: This is in reply to your letter of December 8, 1978, asking whether the front and rear clearance lamps on your Model 870 Urban transit coach comply with Federal Motor Vehicle Safety Standard No. 108. The front clearance lamps on the Model 870 are combined with the turn signal lamps, side marker lamps, and side reflex reflectors. The units are located "on line with and just outboard of each rectangular headlamp," with lens center 32 inches above the road surface, at a point that appears to be at the vehicle's overall width. The rear clearance lamps are combined with the stop lamps and rear side marker lamps, their horizontal center lines 64 inches above the road surface, at approximately the vehicle's overall width. Front and rear identification lamps are mounted at the top of the vehicle. The general rule expressed by Table II of Standard No. 108 is that clearance lamps must be mounted "to indicate the overall width of the vehicle ... and as near the top thereof as practicable." But a partial exception is provided by S4.3.1.4.: When the rear identification lamps are mounted at the extreme height of the vehicle, rear clearance lamps need not meet the requirement of Table II that they be located as close as practicable to the top of the vehicle."
This means that the mid-body location of the rear clearance lamp is acceptable since the rear identification lamps are at the extreme height of the vehicle. But the exception does not extend to the front clearance lamps. While Standard No. 108 allows the manufacturer to determine what location is "as close as practicable to the top of the vehicle", there will be instances when the overall width of the vehicle will not be indicated by the highest location. In such instances the best location will be the one that most closely approximates the intent behind the requirement - to indicate the overall width. Specifically with reference to the Model 870, it appears to us that the close proximity of the combination lamp to the headlamp may result in the effectiveness of the clearance lamp being impaired by the brightness of the headlamp, and that the most practicable location sufficiently indicating the overall width of the vehicle, would be at the outer edges of the body directly below the windshield. Sincerely, Joseph J. Levin, Jr. Chief Counsel GRUMMAN FLXIBLE 970 PITTSBURGH DRIVE DELAWARE, OHIO 43015 614/369-7671 Telex : 245484 70-0220rlr December 8, 1978 Office of Chief Counsel National Highway Traffic Safety Administration 400 Seventh Street S.W. Washington, D.C. 20590 References: (a) FMVSS No. 108. Lamps, Reflective Devices, and Associated Equipment, current edition. (b) Grumman flxible Model 870 Advanced Design Transit Coach, photographs attached. (c) Certificates of conformance copies attached. Dear Sirs:
Your assistance is requested with respect to an official interpretation of reference (a) above as it relates to the installation location of the clearance lamps on our new Grumnan Flxible Model 870 urban transit coach as shown in the enclosed photographs. Refering to Photograph #1, the amber lamp seen on line with and just outboard of each dual, rectangular headlamp is a combination lamp which performs the functions of a turn signal lamp, a clearance lamp, a sidemarker lamp and a side reflex reflector. The lamp contains a single, dual-filament bulb. A 3 c.p. filament provides the light source for the combination clearance/sidemarker lamp functions. and a 32 c.p. filament provides the light source for the front turn signal function. This lamp has been certified as being in conformance with FMVSS No. 108 by the manufacturer (See Attachment #1) and certificates of approval have been issued by the American Association of Motor Vehicle Administrators (See Attachment #2) and the Department of California Highway Patrol (See Attachment #3). These lamps are mounted with lense centers 32 inches above road surface, on the outermost edges of the vehicle front view envelope thus indicating the overall width of the Model 870. It should be noted from Photo #1 that the vehicle sides converge from a point just beneath the baseline of the windshield up to the topmost roof corners. The amount of this convergence is such that each roof corner is eleven inches inboard if the base of the windshield cornerpost. Therefore, clearance lamps mounted at the top-most roof corners would identify the vehicle as being twenty-two inches narrower than it actually is. Our rear exterior lamp configuration is shown in Photo #4. The upper red lamp on each outer edge of the rear view functions as a stop signal lamp, a clearance lamp and a sidemarker lamp. The horizontal center line of this lamp as installed is 64 inches above road surface. The lower red lamp functions as a tail lamp, a turn signal lamp, rear reflex reflector and a side reflex reflector. It's horizontal center line as intalled is 50 inches above road surface. Each lamp contains a single, dual-filament 3 c.p. & 32 c.p.) bulb. The stop signal and turn signal functions utilize the 32 c.p. filament. The clearance, sidemarker and tail lamp functions utilize the 32 c.p. filament. The white lamp shown between the two red lamps on each side are backup lamps. Attachments #4, #5 and #6 are copies of the certificates associated with these lamp units. We would greatly appreciate a review and evaluation by the Office of the Chief Counsel, National Highway Traffic Safety Administration, of the installation locations of the clearance lamps on the Model 870 bus as regards to conformance with the applicable requirements of FMVSS No. 108. Sincerely, R.L. Ratz, P.E. Product Safety Engineering Enclosures |
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ID: nht79-2.39OpenDATE: 06/20/79 FROM: AUTHOR UNAVAILABLE; F. Berndt; NHTSA TO: J. H. Latshaw, Jr., Esq. TITLE: FMVSS INTERPRETATION TEXT: This is in reply to your letter of March 13, 1979, to John Womack of this office on behalf of your client Ennova, Inc. Ennova wishes to market a "back rack carrier", and you have asked several questions with respect to its legality under Federal requirements. The photographs which you enclosed show that the carrier structure is attached to both the front and rear bumpers, and that loads may be carried on the top of the vehicle as well as on a shelf directly behind the vehicle's rear bumper. Your questions and our answers are: "1. Are equipment carriers which fasten to a privately owned motor vehicle regulated by the National Highway Traffic and Safety Act (hereinafter, the NHTSA) so that state law in this area is pre-empted? 2. Does the NHTSA contain any standards or regulations pertaining to roof racks or equipment carriers? Does the motor vehicle safety act contain any such regulations?" An equipment carrier that attaches to a motor vehicle is an item of "motor vehicle equipment" as defined by 15 U.S.C. 1391(4), and your client is a "manufacturer" as defined by 15 U.S.C. 1391(5). There are no Federal motor vehicle safety standards that cover this type of motor vehicle equipment, and, therefore, a State is not preempted by 15 U.S.C. 1392(d)) from prescribing its own safety standards for it. If a safety related defect were discovered in the "Back Rack", Ennova would be responsible for notification and remedy of it, as required by 15 U.S.C. 1411 et seq. "3. Does the NHTSA establish any guidelines for motor vehicle bumpers or fenders which the Back Rack T.M. Carrier appears to violate? Does the fact that the rear platform extends out behind the vehicle place the Rack in contravention of any Federal standards? The Back Rack is intended to become affixed to the rear bumper in a semi-permanent manner and protrude therefrom. Does this bring the carrier into a regulated area? Is so, what is the citation of the regulations and what must be done to conform the platform to same? 4. Does the height, width or depth of any aspect of the Back Rack T.M. Carrier present a problem? 5. The structural supports of the Back Rack T.M. Carrier obscure the vehicle's lighting in some aspects both front and rear. Does the obstruction violate any provisions of the NHTSA or the Motor Vehicle Safety Act? 8. If the Back Rack T.M. Carrier as it appears in the photographs were installed by a dealer, would it be in contravention of any federal law, standard or regulation exclusive of laws relating to products liability and defective equipment." Your questions concern our jurisdiction over a vehicle before and after its sale to its first purchaser for purposes other than resale. A dealer has the responsibility to deliver to its owner a new vehicle in full compliance with all applicable Federal motor vehicle safety standards. Paragraph S4.1.3 of Standard No. 108 prohibits the installation of any "additional lamp, reflective device, or other motor vehicle equipment . . . that impairs the effectiveness of lighting equipment required by this standard." Paragraph S4.3.1 requires that "no part of the vehicle shall prevent a parking lamp, taillamp, stop lamp, turn signal lamp, or backup lamp from meeting its photometric output at any applicable group of test points specified in Figures 1 and 3 [Standard No. 108], or prevent any other lamp from meeting the photometric output at any test point specified in any applicable "SAE Standard on Recommended Practice". Therefore, a dealer could not deliver a new car with the Back Rack installed if it impairs the effectiveness of the car's lamps or reflectors or impairs photometric output. After sale, a dealer (or distributor or manufacturer, but not the vehicle owner) has a responsibility under 15 U.S.C. 1397(a)(2)(A) of not "knowingly rendering inoperative in whole or in part, any device or element of design installed on . . . a motor vehicle . . . in compliance with an applicable Federal motor vehicle safety standard . . ." In the context of Standard No. 108 we have equated a rendering inoperative with impaired effectiveness or impaired photometrics so that the same consideration would apply; a dealer could not install the Back Rack on a used vehicle if it affects compliance with Standard No. 108. The installation of the Back Rack appears to present some compliance problems. Based upon an informal review and the photographs you submitted, the front part of the carrier may reduce headlamp candlepower output below the required minimum at several test points, as for example, at test points HV, H-3R and 3L and H 9R and 9L on the upper beam, and at test points 1 1/2 D-2R, 1/2 D-1 1/2 R on the low beam. Looking at the turn signals which are required to have an 8.0 square inch minimum projected luminous area, the carrier support design may mask them to the extent that the direction of the turn signal might not be clearly understood. The carrier support location may not allow these lamps to provide an unobstructed effective projected illuminated area of outer lens surface, excluding reflex, of at least 2 square inches, measured at 45 degrees to the longitudinal axis of the vehicle. This requirement must also be met by the taillamps. Further with respect to the taillamps, with the carrier in place, they may not be visible through a horizontal angle from 45 degrees to the left and/or right, as Standard No. 108 requires. The design location of the carrier supports may reduce the minimum effective projected luminous area of the stop lamps below the 8 square inch minimum of Standard No. 108. As for backup lamps, the visibility requirements are complex, those of SAE Standard J593c as modified by S4.1.1.22 of Standard No. 108, but in essence the lamps must be "readily visible" to use your phrase. These interpretations are based upon the photographs you supplied, and are meant to be illustrative as there are many different lighting configurations on vehicles, and we do not know that the Back Rack would affect compliance in all instances. "7. What are the dimensional requirements of headlight, parking, directional and tail lights? What percentage of these lenses must be totally visible?" Dimensional requirements of headlights conform to SAE J571d, Dimensional Specifications of Sealed Beam Headlamp Units, June 1966, parking lights, SAE J 222, Parking Lamps (Position Lamps) December 1970, directional lights (turn signals) SAE J588e, Turn Signal Lamps (Rear Position Light), August 1970. Copies of the foregoing SAE Standards are attached. In addition, the minimum and maxima of lens visibility requirements for parking lamps, turn signal lamps and taillamps are set forth in these SAE Standards. The minimum and maximum photometric requirements of headlights are set forth in SAE J 579a, August 1965 and J 579c, December 1974, as well as the design parameters of rectangular headlamps units SAE J 1132, Sealed Beam Headlamp Units for Motor Vehicles (copies also attached). I hope this answers your questions. SINCERELY, March 13, 1979 John Womack, Esquire Office of General Counsel Department of Transportation Re: The Back Rack T.M. Carrier by Ennova, Inc. Dear John: I have taken the liberty of forwarding this letter and the enclosure herewith to you so that you may channel same to the proper individual for inspection. Your involvement in this matter will produce better results than if I sent the material to the Department generally. Our client, Ennova, Inc., seeks to market and arrange for the distribution of the Back Rack T.M. Carrier to dealers for installation on privately owned motor vehicles. Prior to the production of the carrier, I would like to determine if the Department of Transportation can detect potential regulatory obstacles or other problems with the product. In addition, I would be pleased to entertain any suggestions which the Department may have. I have enclosed six (6) photographs (two with detailed measurements) plus a letter explaining the Carrier written by the designer. Those materials are for the sole use of the Department of Transportation in its consultations with the above-referenced lawfirm. The information and specifications contained within the enclosures will be divulged to the public only upon the Department's receipt of a carefully constructed, detailed and specific request for same. This request must meet the requirements of the Freedom of Information Act before the Department is obligated to release the requested information. My questions in reference to the Back Rack T.M. Carrier are as follows: 1. Are equipment carriers which fasten to a privately owned motor vehicle regulated by the National Highway Traffic and Safety Act (hereinafter, the NHTSA) so that state law in this area is pre-empted? 2. Does the NHTSA contain any standards or regulations pertaining to roof racks or equipment carriers? Does the motor vehicle safety act contain any such regulations? 3. Does the NHTSA establish any guidelines for motor vehicle bumpers or fenders which the Back Rack T.M. Carrier appears to violate? Does the fact that the rear platform extends out behind the vehicle place the Rack in contravention of any federal standards? The Back Rack is intended to become affixed to the rear bumper in a semi-permanent manner and protrude therefrom. Does this bring the carrier into a regulated area? If so, what is the citation of the regulations and what must be done to conform the platform to same? 4. Does the height, width or depth of any aspect of the Back Rack T.M. Carrier present a problem? 5. The structural supports of the Back Rack T.M. Carrier obscure the vehicle's lighting in some aspects both front and rear. Does the obstruction violate any provisions of the NHTSA or the Motor Vehicle Safety Act? In particular, does the Carrier violate in any manner the provisions of Section 103 of the Motor Vehicle Safety Act? 6. What is the minimum amount of ascertainable candle power required to be visible from each vehicular light subsequent to sunset? Must back-up lights be readily visible? 7. What are the dimensional requirements of headlight, parking, directional and tail lights? What percentage of these lenses must be totally visible? 8. If the Back Rack T.M. Carrier as it appears in the photographs were installed by a dealer, would it be in contravention of any federal law, standard or regulation exclusive of laws relating to products liability and defective equipment. Please arrange for your Department to have someone consider the Carrier and these questions carefully. I would appreciate it if the Department would contact me personally or in writing with a concrete response to this inquiry within one (1) month. If there are any procedures which I can follow to obtain a letter of approval indicating that the Carrier does not structurally violate any federal standard, please apprise me of same. In addition, please forward me the name of the DOT representation assigned to respond to this inquiry. Thank you for your kind cooperation in this matter. John H. Latshaw, Jr. ENCLS. cc: RICHARD R. CHUTTER -- PRES., ENNOVA, INC. PRODUCTION MODEL WILL BE 50 DEGREES (Graphics omitted) COPYRIGHT (C) Ennova. Inc. 1978 BACK RACK TM Carrier by Ennova (Graphics omitted) (Graphics omitted) (Graphics omitted) (Graphics omitted) |
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ID: 1983-2.34OpenTYPE: INTERPRETATION-NHTSA DATE: 07/27/83 FROM: PEKKA SUURONEN -- RACEMARK INTERNATIONAL INC TO: CHIEF COUNSEL NHTSA TITLE: NONE ATTACHMT: ATTACHED TO LETTER DATED 11/17/83 FROM FRANK BERNDT -- NHTSA TO PEKKA SUURONEN, REDBOOK A25, STANDARD 108, NOA 30 TEXT: Gentlemen: On behalf of our principal "Hella" (Germany), I am writing to you to find out about headlamp legality. (1) Is a sealed headlamp with replaceable European H4 bulb considered legal (like Cibie BOBI), provided it meets with all the applicable SAE standards? (2) As above, but with the new "Ford" bulb (6 standard sizes)? I am looking forward to your reply. Yours truly, |
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ID: nht88-2.80OpenTYPE: INTERPRETATION-NHTSA DATE: 08/01/88 EST FROM: ERIKA Z. JONES -- CHIEF COUNSEL, NHTSA TO: C. DIANNE BLACK -- ENGINEERING MANAGER, JAGUAR CARS, INC. TITLE: NONE ATTACHMT: MEMO DATED 4-14-88, TO ERIKA Z. JONES, FROM C. DIANNE BLACK -- JAGUAR, REF: FMVSS 108, HEADLAMP LEVELLING SYSTEM TEXT: Thank you for your letter of April 14, 1988, providing further information about the Jaguar headlamp levelling system discussed in your letters of June and October 1987 to which I responded on February 1, 1988. We support your efforts to call the driver's attention to the fact that the system does not automatically return to the "zero" position from either of the two adjustment positions when those loading conditions no longer exist. |
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ID: nht92-8.6OpenDATE: April 3, 1992 FROM: Herr Spingler -- Entwicklung Lichttechnik Systeme, Robert Bosch GmbH TO: Richard van Iderstine -- Office of Rulemaking, NHTSA TITLE: None ATTACHMT: Attached to letter dated 5/29/92 from Paul J. Rice to Herr Spingler (A39; Std. 108) TEXT: For a new Porsche-car, we have decided to develop a headlamp as shown in the attached drawing. The lowbeam will be provided by an ellipsoid, the highbeam by a parabola. When highbeam is on, both bulbs will be on simultaneonsly. My question is: Will this headlamp meet the FMVSS-108-requirements concerning the location on a car? Thanks in advance for a quick answer. |
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ID: aiam0695OpenMr. Bernard Belier, U.S. Resident Engineer, CITROEN, 801 Second Avenue, New York, NY 10017; Mr. Bernard Belier U.S. Resident Engineer CITROEN 801 Second Avenue New York NY 10017; Dear Mr. Belier: This is in reply to your letter of April 24, 1972, in which you pose questions about the operation of the seat belt warning system under Standard 208 and about the intent of the headlamp adjustment requirement under Standard 215.; Your questions on Standard 208 deal with the requirement in S7.3.3 tha the warning system in a vehicle with an automatic transmission must not operate when the engine is operating and the gear selector is in the 'Park' position. In answer to your first question, if the two conditions for non-operation exist, the warning system must not operate, regardless of the position of the hand brake lever. If either condition does not exist, e.g., the transmission is in 'Park' but the engine is not operating, it would be permissible to have the system operate, and its operation could be controlled by the hand brake so long as the hand brake circuitry does not interfere with the mandatory operation of the system under S7.3.1 and S7.3.5.; If the shift is in the neutral position, as stated in your secon question, you are free to choose whether to have the system operate or not, since S7.3 does not require either operation or non-operation when the transmission is in neutral.; In response to your last question on Standard 208, an 'operatin engine' is an engine that is rotating. It is permissible to have a system in which the warning operates when the transmission is in 'Park' and the ignition is 'On', but the warning must shut off when the engine begins to operate.; Your question on Standard 215 is whether the headlamps must b adjustable after the tests 'so as to permit restoration of normal lighting' or whether it is sufficient for the lamps to be adjustable plus or minus 4 degrees vertically and horizontally whether or not this restores normal lighting. Our reply is that the requirement is intended to provide for the safe operation of the lamps after impact and that the lamps must therefore be adjustable in a manner that restores normal lighting.; Sincerely, Richard B. Dyson, Assistant Chief Counsel |
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ID: nht92-7.48OpenDATE: April 6, 1992 FROM: Gonshiro Miyoshi -- Manager, Design Administration Dept., Technical Division Ichikoh Industries, Ltd. TO: Paul Jackson Rice -- Chief Counsel, NHTSA TITLE: Our Reference LO4-11 ATTACHMT: Attached to letter dated 5/8/92 from Paul J. Rice to Gonshiro Miyoshi (A39; Std. 108) TEXT: This letter is in regards to the interpretation of headlamp arrangement in FMVSS No. 108. We would like to know your opinion regarding the below mentioned arrangement of headlamp system consisting of two lamps, each containing two light sources. Is it permissible to have the bulb center of the lower beam lower than that of the upper beam (maximum height difference is 10mm) if they are arranged horizontally? Kindly let us know your opinion concerning the above matter. |
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ID: nht94-2.67OpenTYPE: Interpretation-NHTSA DATE: May 5, 1994 FROM: John Womack -- Acting Chief Counsel, NHTSA TO: Tilman Spingler -- Robert Bosch GmbH TITLE: None ATTACHMT: Attached to letter dated 3/25/94 from Tilman Spingler to John Womack (OCC-9889) TEXT: This responds to your letter of March 25, 1994, asking for an interpretation of Motor Vehicle Safety Standard No. 108 with respect to integral beam headlighting systems. You reference a letter of this office to Toyota in which we permit location of the light source control module outside the headlamp housing but permanently attached to it by a cable. You have asked whether there are "requirements for this cable concerni ng indivisibility and integration...." There are no such requirements for the cable in Standard No. 108, and the headlamp manufacturer may adopt the construction that it has determined is most suitable for its design. |
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ID: nht94-5.50OpenDATE: May 5, 1994 FROM: John Womack -- Acting Chief Counsel, NHTSA TO: Tilman Spingler -- Robert Bosch GmbH TITLE: None ATTACHMT: Attached to letter dated 3/25/94 from Tilman Spingler to John Womack (OCC-9889) TEXT: This responds to your letter of March 25, 1994, asking for an interpretation of Motor Vehicle Safety Standard No. 108 with respect to integral beam headlighting systems. You reference a letter of this office to Toyota in which we permit location of the light source control module outside the headlamp housing but permanently attached to it by a cable. You have asked whether there are "requirements for this cable concerning indivisibility and integration...." There are no such requirements for the cable in Standard No. 108, and the headlamp manufacturer may adopt the construction that it has determined is most suitable for its design. |
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ID: nht79-1.34OpenDATE: 11/09/79 FROM: AUTHOR UNAVAILABLE; F. Berndt; NHTSA TO: SEV Corporation TITLE: FMVSS INTERPRETATION TEXT: NOV 9 1979 Mr. H. J. T. Young Vice president - Technical Affairs SEV Corporation 33201 Harper Avenue St. Clair Shores, Michigan 48082 Dear Mr. Young: This is in reply to your letter of September 24, 1979, to Mr. Vinson of this office in which you requested an interpretation of S4.1.1.19 of Federal Motor Vehicle Safety Standard No. 108. S4.1.1.19 states: A lamp manufactured on or after January 1, 1974 and designed to use a type of bulb that has not been assigned a mean spherical candlepower rating by its manufacturer and is not listed in SAE Standard J573d "Lamp Bulbs and Sealed Units", December 1968, shall meet the applicable requirements of this standard when used with any bulb of the type specified by the lamp manufacturer, operated at the bulb's design voltage. A lamp that contains a sealed-in bulb shall meet these requirements with the bulb operated at the bulb's design voltage. It is noted that this paragraph consists of two sentences. You have asked whether the "lamp" and "bulb" of the second sentence are the same "lamp" and "bulb" of the first sentence.
The answer is no. The first sentence would require testing, at the bulb's design voltage, of bulbs used in sealed beam headlamps but not of bulbs used in, for example, taillamps; the former, though listed in J573d (Table 2), is not assigned a mean spherical candlepower rating since these bulbs emit shaped beams while the latter are both listed in J573d and have assigned mean spherical candlepower ratings. However, if the latter is used in the sealed lamp, it is tested at the bulb's design voltage rather than using the rated mean spherical candlepower. Furthermore, the rulemaking history of the paragraph clearly indicates that the two requirements are separate. As the agency noted in the preamble to the proposal, "The proposal specifies that when no rating has been assigned by the bulb manufacturer or the SAE or if the lamp is sealed and the bulb cannot be replaced, the bulb shall be operated at design voltage" (emphasis supplied) (38 FR 16230). You noted that your question relates to the voltage required by Standard No. 108 for the photometric testing of a sealed beam headlamp that utilizes a European halogen bulb that meets ECE Regulation 37. Since J579c requires the test voltage to be 12.8 volts for all the sealed beam bulbs, the photometric tests should be at 12.8 volts and not at the so-called "system voltage" of 12 volts. I hope this is responsive to your request. Sincerely, Frank Berndt Chief Counsel Mr. Taylor Vinson Office of the Chief Counsel NATIONAL HIGHWAY TRAFFIC SAFETY ADMINISTRATION 400 Seventh Street S W WASHINGTON DC 20590 September 24 1979 Dear Mr Vinson Request for Interpretation With reference to S4.1.1.19 of FMVSS 108, are the "lamp" and "bulb" of the second sentence the same as these two items referred to in the first sentence, that is to say, is the bulb of the second sentence one to which the two conditions attaching to the bulb of the first sentence also apply? This question relates to the voltage required by FMVSS 108 for the photometric testing of a sealed beam headlamp that comprises, in part, a "sealed-in bulb" that is an H1, H2, H3 or H4 halogen bulb that bears the E-mark signifying that it is in compliance with E/ECE/TRANS/505/rev.1/Add.36 Regulation 37 of the Geneva Agreement of 20 March 1958 as adopted by the several European governments. Yours sincerely
H J T YOUNG Vice President - Technical Affairs |
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.