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: aiam1045OpenMr. John Morse, Monsanto Co., 1101 17th Street, N.W., Suite 604, Washington, D.C. 20036; Mr. John Morse Monsanto Co. 1101 17th Street N.W. Suite 604 Washington D.C. 20036; Dear Mr. Morse: #This is in reference to a question that has bee raised in telephone conversations, by Monsanto, as to whether the NHTSA allows a manufacturer of newly developed tires to run them on the public roads before they are certified as conforming to Standard No. 109. #The answer is no. We have, to the best of our knowledge, allowed no exception to the requirement that all tires to which a motor vehicle safety standard is applicable must conform to the standard an be certified as such. #Your truly, Richard B. Dyson, Assistant Chief Counsel; |
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ID: aiam0672OpenMr. George C. Nield, Engineering Advisor, Messrs. Busby Rivkin Sherman Levy and Rehm, 816 Connecticut Avenue, N.W., Washington, DC 20006; Mr. George C. Nield Engineering Advisor Messrs. Busby Rivkin Sherman Levy and Rehm 816 Connecticut Avenue N.W. Washington DC 20006; Dear Mr. Nield: In your letter of April 5, you ask whether certain items of lightin equipment that you listed must be certified as conforming to applicable Federal standards, even though the assemblies of which they are a part may require certification.; This will confirm your understanding that the listed items need not b certified. The items of lighting equipment requiring certification are those equipment items specified in Tables I and III of Standard No. 108.; Yours truly, Richard B. Dyson, Assistant Chief Counsel |
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ID: aiam0671OpenMr. George C. Nield, Engineering Advisor, Messrs. Busby Rivkin Sherman Levy and Rehm, 816 Connecticut Avenue, N.W., Washington, DC 20006; Mr. George C. Nield Engineering Advisor Messrs. Busby Rivkin Sherman Levy and Rehm 816 Connecticut Avenue N.W. Washington DC 20006; Dear Mr. Nield: In your letter of April 5, you ask whether certain items of lightin equipment that you listed must be certified as conforming to applicable Federal standards, even though the assemblies of which they are a part may require certification.; This will confirm your understanding that the listed items need not b certified. The items of lighting equipment requiring certification are those equipment items specified in Tables I and III of Standard No. 108.; Yours truly, Richard B. Dyson, Assistant Chief Counsel |
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ID: aiam1871OpenMr. Kazuhiko Aoki,2-3 Nihonbashi Koami-cho,1-chome,Chuo-ku, Toykyo, Japan 103; Mr. Kazuhiko Aoki 2-3 Nihonbashi Koami-cho 1-chome Chuo-ku Toykyo Japan 103; Dear Mr. Aoki:#This responds to your January 30, 1975, question whethe the test procedure of S7.7.1 in Standard No. 105-75, *Hydraulic brake systems*, refers to the parking brake in the next to the last sentence which states that it 'may be necessary to reapply *it* if the vehicle move slightly' (emphasis added).#The word 'it' refers to the service brake system, and not the parking brake system. This sentence permit application of the service brake system slack due to rotation of the brake shoes and drum prior to bottoming against the anchor pin.#Sincerely,James C. Schultz,Chief Counsel; |
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ID: aiam0991OpenMr. Satoshi Nishibori, Nissan Motor Co., Ltd., 560 Sylvan Avenue, Englewood Cliffs, NJ 07632; Mr. Satoshi Nishibori Nissan Motor Co. Ltd. 560 Sylvan Avenue Englewood Cliffs NJ 07632; Dear Mr. Nishibori: This is in reply to your letter of January 23, 1973, concerning th sequence of manual switch operation under S7.4.4 of Motor Vehicle Safety Standard No. 208. Your question is whether S7.4.4 requires the manual switch and ignition switch to be operated in a specific order.; S7.4.4 does no require any specific sequence. After the ignition ha been turned off, it can be made operable either by turning the ignition switch on, then operating the manual switch, of by operating the manual switch and then turning the ignition on.; Yours truly, Richard B. Dyson, Assistant Chief Counsel |
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ID: aiam3189OpenMr. Doug Smith, 3595 Santa Fe Avenue #156, Long Beach, California 90810; Mr. Doug Smith 3595 Santa Fe Avenue #156 Long Beach California 90810; Dear Mr. Smith: This responds to your December 6, 1979, letter asking questions abou Standard No. 211, *Wheel Nuts, Wheel Discs, and Hub Caps*. In particular, you ask whether winged projections are permitted in a rim as long as they do not extend beyond the lip of a rim or the sidewall of a tire.; When the standard was issued, the agency concluded that winge projections could catch the clothing of children or pedestrians thereby posing safety hazard. As a result the standard prohibits the use of all winged projections regardless of the extent to which they extend from a rim. The standard however, only prohibits winged projections and does not affect other projects from a rim.; Sincerely, Frank Berndt, Chief Counsel |
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ID: aiam0467OpenMr. James V. Blethen, 924 47th Avenue, N.E., Minneapolis, Minnesota 55421; Mr. James V. Blethen 924 47th Avenue N.E. Minneapolis Minnesota 55421; Dear Mr. Blethen: In your letter of October 21 to Mrs. Petruska, out docket clerk, yo ask whether your rearview mirror idea is 'legal or permissible.' My answer, of course, is restricted to the permissibility of such a mirror by the Federal motor vehicle safety standards.; Federal Motor Vehicle SAfety Standard No. 111, *Rearview Mirrors*, doe not apply to mirrors *per se* by specified requirements that must be met by rearview mirrors mounted in new passenger cars and multipurpose passenger vehicles. There are no Federal safety requirements directly applicable to mirrors, and thus manufacture and sale of your rearview mirror is not prohibited by the National Traffic and Motor Vehicle SAfety Act of 1966.; Sincerely, Lawrence R. Schneider, Chief Counsel |
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ID: aiam0474OpenMr. H. A. Sage, Director of Research and Engineering, Truck- Lite Company, P. O. Box 387, Jamestown, NY, 14701; Mr. H. A. Sage Director of Research and Engineering Truck- Lite Company P. O. Box 387 Jamestown NY 14701; Dear Mr. Sage: This is in reply to your letter of October 15, 1971, to Mr. Lewis Owe of this Office concerning the coating of Lexan lenses.; Plastic lenses used in the required lamps are required by Federal Moto Vehicle Safety Standard No. 108 to meet SAE J576, which specifies no loss of surface luster and no surface deterioration. This Agency does not have the authority to 'waive' any requirements of a Federal motor vehicle safety standard.; If you believe that motor vehicle safety does not demand requirement of this severity, you may submit a petition asking for an appropriate amendment of Standard No. 108.; Sincerely, E. T. Driver, Director, Office of Operating Systems, Moto Vehicle Programs; |
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ID: aiam1936OpenMr. Don W. Wieriman, TTMA, 2430 Pennsylvania Avenue, N.W., Washington, DC 20037; Mr. Don W. Wieriman TTMA 2430 Pennsylvania Avenue N.W. Washington DC 20037; Dear Mr. Wieriman: This responds to the Truck Trailer Manufacturers Association's May 1 1975, request for a determination of what speed the National Highway Traffic Safety Administration (NHTSA) considers as 'highway speeds' in establishing gross vehicle weight ratings (GVWR) and gross axle weight ratings (GAWR) under the requirements of 49 CFR S 567.4(g)(3) and (4).; For purposes of GVWR-GAWR calculations, NHTSA will consider 'highwa speeds' to be the 60 mph value used by the United States Tire and Rim Association in assigning unqualified ratings to their tires. Therefore, trailers which are capable of speeds of 60 mph or more should be assigned ratings which reflect vehicle capabilities at 60 mph.; Sincerely, James C. Schultz, Chief Counsel |
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ID: aiam3120OpenMr. Jeff Jacobovitz, Federal Trade Commission/PC, 6th & Pennsylvania Avenue, N.W., Washington, DC 20580; Mr. Jeff Jacobovitz Federal Trade Commission/PC 6th & Pennsylvania Avenue N.W. Washington DC 20580; Dear Mr. Jacobovitz: This is in response to your letter of September 11, 1979, askin whether the National Highway Traffic Safety Administration (NHTSA) has adopted the Rubber Manufacturers Association (RMA) definition of mud and snow tire or has made any official statement regarding the validity of that definition. NHTSA has not adopted the RMA definition for use in any agency regulations, relating either to safety standards or to tire quality grading, nor has NHTSA made any official statement regarding the validity of the definition. If I can be of further assistance, do not hesitate to contact me.; Sincerely, Frank Berndt, Chief Counsel |
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.