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 |
|---|---|
ID: nht72-2.34OpenDATE: 04/13/72 FROM: AUTHOR UNAVAILABLE; R. B. Dyson; NHTSA TO: Amerace - Esna Corporation TITLE: FMVSS INTERPRETATION TEXT: In your letter of February 4 to Mr. Schneider you discussed differences between SAS Standard J594d, March 1957, Reflex Reflectors, and its successor J594e, March 1970. You asked "whether relief can be granted in the unnecessary specular restriction appearing in Federal Motor Vehicle Safety Standard No. 108 because of its inclusion of J594d rather than J594e." We have reviewed your letter and the administrator has determined that the issue you raised merits (Illegible Word) of rulemaking. I enclose a copy of a notice proposing an amendment to Standard No. 108 to substitute SAE J594e as the referenced requirement for reflex reflectors. |
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ID: nht92-1.39OpenDATE: 12/07/92 FROM: RICHARD LANGLAIS -- PRELCO, INC. TO: MARVIN SHAW TITLE: FVMSS 205 ATTACHMT: ATTACHED TO LETTER DATED 2-23-93 FROM JOHN WOMACK TO RICHARD LANGLAIS (A40; STD 205; PART SS2); ALSO ATTACHED TO LETTER DATED 11-26-91 FROM KATHLEEN DEMETER TO RICHARD LANGLAIS TEXT: Last year, I received the information regarding the procedure to follow in order to get a D.O.T. number (I have enclosed a copy). Would it be possible for you to give me more details about items 5, 6 and 7? Who can be our agent? Do you know some agents or firms which are specialized in this kind of service? I would appreciate if you could get back to me at your earliest convenience. Thanking you in advance for your collaboration, I remain, |
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ID: nht74-4.49OpenDATE: 01/25/74 FROM: AUTHOR UNAVAILABLE; Richard B. Dyson; NHTSA TO: Dow Corning Corp. TITLE: FMVSS INTERPRETATION TEXT: This is in reply to your letter of January 10, 1974, to Mr. Schneider. It is uncertain whether "some time in July of 1974 Federal standards will become effective relating to silicone brake fluids." The proposed effective date for DOT 5 fluids is July 1, 1974, but the comments on this rulemaking action are still under consideration and the actual effective date, if the proposal is adopted, will probably be somewhat later. It is true that S5.4.3 of Standard No. 105a does not require that all reservoir labelling be "DOT 3." The letters "e.g." mean "for example." If DOT 4 is the recommended fluid then "DOT 4" would be the appropriate insertion in the required statement. |
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ID: 10104Open Mr. Keith E. Smith Dear Mr. Smith: This responds to your letter asking whether the National Highway Traffic Safety Administration (NHTSA) considers automotive and motorcycle braking systems to be "safety devices." As explained below, the agency considers such systems to be items of motor vehicle equipment. Please note that neither the National Traffic and Motor Vehicle Safety Act (formerly at 15 U.S.C. 1381 et seq. and recently codified in Title 49 of the U.S. Code) nor the agency's regulations in Title 49 of the Code of Federal Regulations use the phrase "safety device." Rather, the statute refers to "motor vehicles" and "motor vehicle equipment." Specifically, motor vehicle equipment is defined, in relevant part, as any system, part, or component of a motor vehicle as originally manufactured or any similar part or component manufactured or sold for replacement or improvement of such system, part, or component or as any accessory, or addition to the motor vehicle ... Under this definition, NHTSA would consider an automotive or motorcycle braking system to be an item of motor vehicle equipment. Please note that the Federal motor vehicle safety standards are issued to meet the need for safety. For example, the purpose of Standard No. 105, which regulates hydraulic brake systems of passenger cars and other specified vehicles, is "to insure safe braking performance under normal and emergency conditions." See S2 of Standard No. 105. Similarly, the purpose of Standard No. 122, which regulates motorcycle brake systems, is "to insure safe motorcycle braking performance under normal and emergency conditions." See S2 of Standard No. 122. I hope this information is helpful. If you have any further questions about NHTSA's safety standards, please feel free to contact Marvin Shaw of my staff at this address or by telephone at (202) 366-2992. Sincerely,
John Womack Acting Chief Counsel ref:VSA d:8/18/94
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1994 |
ID: nht93-7.52OpenDATE: November 4, 1993 FROM: John Womack -- Acting Chief Counsel, NHTSA TO: John B. Walsh -- Legal Affairs Manager, American Suzuki Motor Corporation TITLE: None ATTACHMT: Attached to letter dated 10/29/93 from John B. Walsh to John Womack (OCC-9263) TEXT: This acknowledges receipt of your letter dated October 29, 1993, requesting an interpretation of the labeling requirements of the recent final rule mandating the installation of air bags in passenger cars and light trucks (58 FR 46551, September 2, 1993). As you suggested in your letter, we believe it would be appropriate to respond to your request in the notice responding to the petitions for reconsideration of the September 2 final rule. If you have any other questions, please contact Mary Versailles of my staff at this address or by phone at (202) 366-2992. |
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ID: nht95-1.35OpenTYPE: INTERPRETATION-NHTSA DATE: January 25, 1995 FROM: Paul Pinoski -- Project Engineer, SLP Engineering, Inc. TO: Philip R. Recht, Chief Counsel, NHTSA TITLE: NONE ATTACHMT: ATTACHED TO 4/24/95 LETTER FROM PHILIP RECHT TO PAUL PINOSKI (A43; STD. 110; PART 567; PART 571); ALSO ATTACHED TO 6/8/94 LETTER FROM JOHN WOMACK TO HAL SULLIVAN TEXT: Dear Mr. Recht: I would like to request your assistance in clarifying a component of the definition of vehicle capacity weight listed in 49 CFR 571.110. Could you define the terms rated cargo load and luggage load and explain how these weights are obtained so that I may calculate vehicle capacity weight? My company is in the middle of a production run of a vehicle that we produce for General Motors and we need to fully understand every component of the GVWR. Expedition of this request would be greatly appreciated . |
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ID: 9263Open John B. Walsh Dear Mr. Walsh: This acknowledges receipt of your letter dated October 29, 1993 requesting an interpretation of the labeling requirements of the recent final rule mandating the installation of air bags in passenger cars and light trucks (58 FR 46551, September 2, 1993). As you suggested in your letter, we believe it would be appropriate to respond to your request in the notice responding to the petitions for reconsideration of the September 2 final rule. If you have any other questions, please contact Mary Versailles of my staff at this address or by phone at (202) 366-2992. Sincerely,
John Womack Acting Chief Counsel ref:208 d:11//4/93 |
1970 |
ID: nht92-5.9OpenDATE: July 28, 1992 FROM: Office of Chief Counsel -- NHTSA TO: Thomas E. Wilde TITLE: None ATTACHMT: Attached to letter dated 9/9/92 from Paul Jackson Rice to Thomas E. Wilde (A39; Std. 208; VSA 108(a)(2)(A) TEXT: I am in the process of obtaining a patent for an airbag device designed to be installed in automobiles that do not already have factory-installed airbags (a.k.a. "retro-fit air bag"). The device will use current air- bag sensor/trigger technology and as such only the "bag" device and delivery method will be patented. I would appreciate your office's advice or comments on any vehicle safety standards that may exist regarding the placement of a retro-fit device in a vehicle. My concern is that there may be some regulations that restrict the use of such devices. Please let me know if you have any questions. Thank you! |
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ID: nht95-4.74OpenTYPE: INTERPRETATION-NHTSA DATE: November 13, 1995 FROM: Tommy Reeder -- Loadcraft Manufacturing Corp. TO: Dave Coleman -- NHTSA TITLE: Lights on Rear of Trailer ATTACHMT: 1/29/96 letter from Samuel J. Dubbin to Tommy Reeder (A44; Std. 108) TEXT: WE HAVE A TRAILER CURRENTLY IN PRODUCTION THAT IS CAUSING A CONCERN ITS ORIGINAL APPLICATION WAS FOR FARM IMPLEMENTS WE NOW HAVE A CUSTOMER USING IT FOR SHIPPING CONTAINERS. IT HAS A TILT DECK -- BECAUSE OF THIS, LIGHTS ON THE EXTREME END TEND TO BE CRU SHED BY ROCKS OR MUD WHEN THE TRAILER DECK IS TILTED TO WINCH SOMETHING ON THE DECK. THE FARM TRAILER USED LIGHTS MOUNTED ON THE FURTHER MOST CROSSMEMBER FACING THE REAR OF TRAILER. DO THE LIGHTS HAVE TO BE AT THE VERY END OF THE TRAILER? WE HAVE STARTED USING A DROP BAR IN ADDITION TO THE LIGHTS ON THE CROSSMEMBER TO INCREASE VISIBILITY OF THE TAIL LIGHTS IN TRAFFIC, -- IS THIS ACCEPTABLE? Drawing omitted. |
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ID: 3110yyOpen Mrs. Debby Funk Dear Mrs. Funk: This responds to your letter of July 5, l99l, as a followup to my letter of June 25. You have asked whether "it would be illegal for the owner of a vehicle that has a center highmounted stop lamp to install an additional rear window brake light? (anywhere in the back window?)" The answer is that it would not be illegal under Federal law for a vehicle owner to install an additional stop lamp anywhere in the back window, providing that all modifications were performed by the owner. However, the legality of the modification would still be subject to State law. You have also asked "What is F.M.V.S.S. 108?" That is Federal Motor Vehicle Safety Standard No. l08 Lamps, Reflective Devices and Associated Equipment. It can be found in Title 49 Code of Federal Regulations, as Section 571.108. If you have further questions, please don't hesitate to write. Sincerely,
Paul Jackson Rice Chief Counsel ref:l08#VSA d:7/30/9l |
2009 |
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.