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: nht71-5.64OpenDATE: 10/14/71 FROM: AUTHOR UNAVAILABLE; Lawrence R. Schneider; NHTSA TO: Truck Equipment & Body Distributors Association TITLE: FMVSR INTERPRETATION TEXT: In your letter of September 8, 1971, you ask whether final-stage manufacturers may use the new vehicle certification label required as of January 1, 1972, before that date. Your members may use the new label before January 1, 1972. Since the two vehicle weight ratings are not required until that date, there is no legal objection either to leaving the appropriate space blank, or to typing the phrase "NOT REQUIRED UNTIL 1/1/72" in the space provided. |
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ID: nht72-5.17OpenDATE: 04/14/72 FROM: AUTHOR UNAVAILABLE; Richard B. Dyson; NHTSA TO: Nissan Motor Co. Ltd. TITLE: FMVSR INTERPRETATION TEXT: This is in reply to your letter of March 29, 1972, in which you ask whether a Certification label "which is made of some kind of hard material other than paper and affixed on the required place by using only one rivet and by gluing" will meet the requirements of section 567.4(b) of the Certification regulations. We would consider such a label to be riveted, and consequently to meet the requirements of section 567.4(b). |
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ID: nht72-5.18OpenDATE: 04/20/72 FROM: AUTHOR UNAVAILABLE; Richard B. Dyson; NHTSA TO: Messrs. Busby Rivkin Sherman Levy and Rehm TITLE: FMVSR INTERPRETATION TEXT: In your letter of April 5, you ask whether certain items of lighting 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 be certified. The items of lighting equipment requiring certification are those equipment items specified in Tables I and III of Standard No. 108. |
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ID: nht91-4.1OpenDATE: May 16, 1991 FROM: Petersen Engineering GmbH TO: NHTSA TITLE: None ATTACHMT: Attached to letter dated 8-8-91 from Paul Jackson Rice to Gabriela Petersen and Hans Petersen (A38; Part 541) TEXT: To our knowledge, there is a law in the U S, which states, that vehicles from a certain categorya, must be coded eyually on 10 different structural parts. Please be so kind, and sent us a written copy of this law. Thanking you in advance for the inconvenience we may have caused you we remain yours faithfully. |
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ID: nht73-3.44OpenDATE: 03/22/73 FROM: AUTHOR UNAVAILABLE; R. B. Dyson; NHTSA TO: Monsanto Co. TITLE: FMVSS INTERPRETATION TEXT: This is in reference to a question that has been 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 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 and be certified as such. |
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ID: aiam0823OpenMr. Trevor Williams, Service Manager, Rolls-Royce, Inc., P.O. Box 189, Paramus, New Jersey 07652; Mr. Trevor Williams Service Manager Rolls-Royce Inc. P.O. Box 189 Paramus New Jersey 07652; Dear Mr. Williams: This is in reply to your letter of May 19, 1971, concerning th placement of vanity mirror in sun visors. We apologize for our delay in responding to your letter. The issues it raised, however, are of consequence to manufacturers other than Rolls-Royce, and concerned basic matters of interpretation of Standard No. 201 which have only recently been resolved.; The National Highway Traffic Safety Administration has determined tha paragraph S3.4.1 of Standard No. 201 does not prohibit the installation by manufacturers of vanity mirrors on sun visors. Consequently, manufacturers are free to incorporate such mirrors into or onto sun visors, including mirror that are recessed into the surface of the visor as in the sample you enclosed.; Sincerely, Robert L. Carter, Associate Administrator, Motor Vehicl Programs; |
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ID: nht73-3.25OpenDATE: 02/14/73 FROM: AUTHOR UNAVAILABLE; Richard B. Dyson; NHTSA TO: Nissan Motor Co., Ltd. TITLE: FMVSS INTERPRETATION TEXT: This is in reply to your letter of January 23, 1973, concerning the 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 not require any specific sequence. After the ignition has been turned off, it can be made operable either by turning the ignition switch on, then operating the manual switch, or by operating the manual switch and then turning the ignition on. |
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ID: nht68-2.16OpenDATE: 06/26/68 FROM: AUTHOR UNAVAILABLE; George C. Nield; NHTSA TO: Volvo, Icorporated TITLE: FMVSS INTERPRETATION TEXT: Thank you for your letter of May 15, 1968, concerning electrically heated glass which you anticipate using for rear windows in your motor vehicles. The present glazing requirement for motor vehicles are covered in Motor Vehicle Safety Standard No. 205, "Glazing Materials." Section S3, Requirements, stipulates that the glazing materials used must conform to U.S.A. Standard Z 26.1-1966, "American Standard Safety Code for Safety Glazing Materials for Glazing Motor Vehicles Operating on Land Highways," July 15, 1966. If the electrically heated glass you mentioned meets the requirements of Standard No. 205, we would have no objection to is use. |
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ID: nht91-2.47OpenDATE: March 25, 1991 FROM: Jerald L. Mikesell, Ed.D. -- Assistant Superintendent, Sierra Vista Public Schools TO: Erika Z. Jones -- Chief Counsel, U. S. Department of Transportation, NHTSA TITLE: None ATTACHMT: Attached to letter dated 4-12-91 from Paul Jackson Rice to Jerald L. Mikesell (A37; Part 571.3) TEXT: We would like to request a copy of the federal regulations regarding school vans being used for transporting of students. We are especially interested in the number of students which can be transported before a van is considered a school bus. We appreciate your help in this matter as an answer to this question is needed as soon as possible. Thank you for your time. |
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ID: nht71-4.42OpenDATE: 11/06/71 FROM: AUTHOR UNAVAILABLE; E. T. Driver; NHTSA TO: Truck-Lite Company TITLE: FMVSS INTERPRETATION TEXT: This is in reply to your letter of October 15, 1971, to Mr. Lewis Owen of this Office concerning the coating of Lexan lenses. Plastic lenses used in the required lamps are required by Federal Motor 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 requirements of this severity, you may submit a petition asking for an appropriate amendment of Standard No. 108. |
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.