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: nht88-1.24OpenTYPE: INTERPRETATION-NHTSA DATE: 02/01/88 FROM: GLENN L. DUNCAN -- THORNE GRODNIK AND RANSEL TO: ERICA Z. JONES -- CHIEF COUNSEL, NHTSA TITLE: OUR CLIENT: UNITED TOOL & STAMPING, INC. MATTER: FMVSS 207 SEATING SYSTEM ATTACHMT: ATTACHED TO LETTER DATED 08/16/88, TO GLENN L. DUNCAN FROM ERIKA Z. JONES, REDBOOK A32, STANDARD 207; LETTER DATED 08/30/79 TO ROBERT J. WAHLS FROM FRANK A. BERNDT; LETTER DATED 04/28/77 TO GORDON P. CRESS FROM FRANK A. BERNDT, STANDARD 210; LE TTER DATED 11/16/87 TO ERICA Z. JONES FROM GLENN L. DUNN RE FMVSS 207 SEATING SYSTEM OCC - 1278 TEXT: Dear Ms. Jones: Enclosed is a copy of the letter we sent to you on November 16, 1987. As of yet, we have received no response. I would appreciate at least an indication that you have received our letter and are working on developing a response, if you are not prepared to actually provide me with a response at this time. Respectfully, ENCLOSURE |
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ID: nht93-9.4OpenDATE: December 6, 1993 FROM: Tilman Spingler -- Automotive Equipment Div. 2, Robert Bosch GmbH TO: Chief Counsel -- NHTSA TITLE: Petition for an "Exemption for Inconsequential Noncompliance" to FMVSS 108, S7.8.5.2 (On Vehicle Aiming) ATTACHMT: Attached to letter dated 1/26/94 from John Womack to Tilman Spingler (A42; Std. 108; Part 573) TEXT: FMVSS 108 requires in the above mentioned paragraph a graduation of not larger than 0.19 degree for the scale of the vertical and 0.38 degree for the scale of the horizontal aim indicator. To make the scales more clearly legible and to avoid confusions we kindly ask for the permission to use scales with graduations of 0.2/0.4 degree. We principally prefer scales with numbers indicating the graduation. It is our opinion that there is no influence on the accuracy of aim because 1/100 degree is less than the width of the graduation-lines on bubble vials and scales used on headlamps. |
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ID: nht95-1.75OpenTYPE: INTERPRETATION-NHTSA DATE: February 24, 1995 FROM: David T. Holland -- President, Europa International, Inc. TO: Mary Versailles -- Office of Chief Counsel, NHTSA TITLE: Via fax # 202-366-3820 RE: Request for clarification of passive restraint phase-in requirements of FMVSS 208. ATTACHMT: ATTACHED TO 4/3/95 LETTER FROM PHILIP R. RECHT TO DAVID T. HOLLAND (A43; STD. 208) TEXT: Dear Ms. Versailles, This letter is to follow up our recent phone conversation where-in you acknowledged that if Europa International, Inc. (R91-002) imports Canadian specification MPV's, such as the Chrysler Minivan, that meets the MPV passive restraint phase-in requirement s of FMVSS 208, Europa will be in compliance as it can count these vehicles toward the required percentage. Please acknowledge this letter by signing below and faxing back or by a letter from your office. Thank you for your assistance. Acknowledged by: Mary Versailles Office of Chief Counsel, NHTSA |
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ID: nht91-6.50OpenDATE: November 1, 1991 FROM: Tadoru Yamamoto -- General Manager, Technical Administration Division, Hino Motors Ltd. TO: Paul Jackson Rice -- Chief Counsel, NHTSA TITLE: Questions on the Interpretation of FMVSS 113 "Hood & Latch System" ATTACHMT: Attached to letter dated 1/13/92 from Paul Jackson Rice to Tadoru Yamamoto (A39; Std. 113) TEXT: Hino Motors, Ltd. is a Japanese manufacturer of heavy duty diesel trucks & buses. We export some kinds of trucks & buses to the United States. We are now developing new model vehicles (cab-over type) which have a front panel. In designing the front panel, we have some questions on the interpretation of FMVSS 113 "Hood & Latch System." It will be greatly appreciated if you would answer the attached questionnaire by Nov. 20, 1991 at the latest. If possible, we would like to receive your answer by facsimile. Our FAX No. is 011-81-0425-86-5006. I'm looking forward to your reply. |
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ID: nht72-2.18OpenDATE: 10/03/72 FROM: AUTHOR UNAVAILABLE; C. A. Baker for E. T. Driver; NHTSA TO: Schlen Body and Equipment Co. TITLE: FMVSS INTERPRETATION TEXT: This is in reply to your letter of September 22 to Mr. Ed Leysath of this Office regarding Interpretations of FMVSS No. 108 on required mounting of marker lights on your dump trailers. In answer to your first problem, a combination front clearance and side marker lamp must meet the requirements for both; therefore, the full 180-degree visibility is required. If you determine that it is not practicable to mount the combination lamp in your alternate location, because of a greater possibility of damage, then separate lamps should be considered. In answer to your second problem, because of the configuration and end use of your dump semi-trailers, your interpretation that rear clearance lamps mounted in a light box just below the rear trailer crossmember are as high as practicable is correct. |
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ID: nht89-3.51OpenTYPE: INTERPRETATION-NHTSA DATE: 12/08/89 FROM: HOWARD KOSSOVER -- CMI TRAILER DIVISION TO: TAYLOR VINSON -- LEGAL COUNCIL - FMVSS - 108 N.H.T.S.A. TITLE: NONE ATTACHMT: ATTACHED TO LETTER DATED 01/09/90 FROM STEPHEN P. WOOD -- NHTSA TO HOWARD KOSSOVER -- CMI TRAILER DIVISION; REDBOOK A35; STANDARD 108 TEXT: Dear Mr. Vinson: I am writing to you in regard to the FMVSS Lighting Code. We are in process of building a semi-trailer for highway use and would like to know if we are in violation of the code with respect to the location of the rear stop, turn & tail lights. This unit is a Rear Discharge trailer designed to haul hot mix asphalt. As the asphalt is discharged out it tends to build up on the rear components. We have recessed the lights approximately 27" from the rear so they will stay clean. I have enclosed some pictures. Does this violate the lighting code? Please let me know. Thank you, PHOTOGRAPHS OMITTED |
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ID: nht93-4.46OpenDATE: June 25, 1993 FROM: Thomas Luckemeyer -- SWF Auto-Electric GmbH TO: Taylor Vinson -- Office of the Chief Counsel TITLE: Turn Signal Lamp ATTACHMT: Attached to letter dated 7-8-93 from John Womack to Thomas Luckemeyer (A41; Std. 108) TEXT: Thank you very much for your detailed answers, which you have sent us by fax on May 28. Nevertheless we have an other question to you with respect to the acceptability of a multiple rear turn signal lamp under FMVSS Standard No. 108. You applicate the SAE J 588 Nov. 84 but the 1990 SAE Ground Vehicle Lighting Manual instructs us to applicate the SAE J 588 Sept. 70. Which SAE Standard is the right one? Please send us an actual copy of the "Table III - Required Motor Vehicle Lighting equipment - Cont." from the FMVSS standard No. 108. Please send your answer by fax. Address see above. Thank you in advance for your help. |
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ID: nht74-2.49OpenDATE: MAY 24, 1974 FROM: ALFRED TEVES TO: JAMES B. GREGORY -- ADMINISTRATOR-NHTSA TITLE: INTERPRETATION OF FMVSS NO. 105-75 ATTACHMT: OCTOBER 3, 1988 LETTER FROM JONES TO BURKARD, EBNER, AND TEVES, FEBRUARY 3, 1981 LETTER FROM KAWANO TO BERNDT, JULY 10, 1974 LETTER FROM DYSON TO NAKAJIMA, MAY 27, 1988 LETTER FROM TEVES TO JONES, AND OCTOBER 9, 1988 LETTER FROM JONES TO BURKARD, EBNER, AND TEVES TEXT: We wish to request clarification of our interpretation of S5.4.1, Master Cylinder Reservoirs, of FMVSS No. 105-75, (105a) published in the Federal Register on May 18, 1973. S.5.4.1 reads as follows: Master Cylinder Reservoirs. A master cylinder shall have a reservoir compartment for each service brake subsystem serviced by the master cylinder. Loss of fluid from one compartment shall not result in a complete loss of brake fluid from another compartment. As we understand it, this Section does not prohibit the designs sketched below. See Illustration on Original F: Front R: Rear C: Clutch |
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ID: nht90-1.52OpenTYPE: Interpretation-NHTSA DATE: February 21, 1990 FROM: Dipl.-Ing H. Westermann -- Hella KG Hueck & Co. TO: Taylor Vinson -- Office of Chief Counsel., NHTSA TITLE: Request for interpretation - CHMSL unity. ATTACHMT: Attached to letter dated 4-25-90 To Dipl.-Ing H. Westermann and From Stephen P. Wood; (A35: Std.108); Also attached to letter dated 2-7-90 To Richard van Iderstine and From Dipl.-Ing. H. Westermann TEXT: Please receive enclosed our request for interpretation, which had accidentally been addressed to Mr. van Iderstine but we were informed that it is yours responsibility. A major uncertainty has arisen with respect to CHMSL unity, where the CHMSL is mounted on the trunk of a convertible (no rear window, appendix 2 of the letter). By ECE unity is defined but SAE and FMVSS 108 yield no such definition. In absence of a clear definition of unity for CHMSL, please let us know, whether the appropriate ECE definition can be applied and whether the designs as shown in the appendices form a CHMSL unity in the sense of FMVSS 108. A soon answer is very much appreciated. |
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ID: nht81-1.33OpenDATE: 03/10/81 FROM: FRANK BERNDT -- NHTSA CHIEF COUNSEL TO: DONALD W. VIERIMAA -- DIRECTOR OF ENGINEERING TRUCK TRAILER MANUFACTURERS ASSOCIATION TITLE: NOA-30 ATTACHMT: LETTER DATED 02/09/81 FROM DONALD W. VIERIMAA TO FRANK BERNDT -- NHTSA, EXCLUSION OF THE TOWBAR OF A PERMANENT TRAILER DOLLY FROM THE FMVSS 108 LENGTH CRITERIA; LETTER DATED 04/04/73 FROM RICHARD B. DYSON -- NHTSA TO PAUL K. WILSON TEXT: Dear Mr. Vierimaa: This is to reply to your letter of February 9, 1981 asking for "exclusion of the towbar of a permanent trailer dolly from the FMVSS 108 length criteria." As you indicated, an opinion by this office in 1973 excluded converter dollies and their integral towbar from inclusion in computation of the overall length of trailers (i.e. S4.1.1.3 which excludes intermediate side marker lamps on vehicles less than 30 feet in overall length). Even though a trailer might be manufactured with a permanent dolly, its function is identical to that of a converter dolly and there is no reason to distinguish one from the other for purpose of computation of overall length. Therefore, overall length may be computed exclusive of either the dolly or the tongue. Sincerely, |
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.