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: nht70-1.21OpenDATE: 06/03/70 FROM: Rodolfo A. Diaz; signature by George Nield -- NHTSA TO: Export Vehicle Engineering Dept. TITLE: FMVSS INTERPRETATION TEXT: Thank you for your letter of May 20 in which you ask "whether the Station Wagon should be construed as a Passenger Car or a Multipurpose Passenger Vehicle". You are correct in your interpretation that a station wagon "does not normally fall under" the category of multipurpose passenger vehicle. However, if a station wagon "is constructed on a truck chassis" or "with special features for occasional off-road operation", such as four-wheel drive, it would be considered a multipurpose passenger vehicle. I hope this clarifies the matter for you. |
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ID: nht68-3.36OpenDATE: 05/10/68 FROM: AUTHOR UNAVAILABLE; David A. Fay; NHTSA TO: Kaiser Jeep Corporation TITLE: FMVSS INTERPRETATION TEXT: Thank you for your letter of April 17, 1968, to Mr. George C. Nield, requesting a confirmation of your interpretation of the visibility requirements for back-up lamps as specified in Motor Vehicle Safety Standard No. 108. You are correct in your interpretation that the visibility requirements for back-up lamps on multipurpose passenger vehicles and trucks will be predicated on the normal driving, or closed tail gate, position. Thank you for your interest in meeting the intent of the requirements of Standard No. 108. |
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ID: nht70-2.22OpenDATE: 08/26/70 FROM: AUTHOR UNAVAILABLE; R. A. Diaz; NHTSA TO: International Manufacturing Company TITLE: FMVSS INTERPRETATION TEXT: This is in reply to your letter of August 12 to Mr. Toms requesting an interpretation of Federal Motor Vehicle Safety Standard No. 211 (Wheel Discs, Wheel Nuts, and Hub Caps). This standard does not prohibit projections per see on wheel equipment items; it prohibits winged projections. Thus there is no limitation on how far a cylindrical projection, for example, may extend beyond the outer edge of the tire. On the other hand, any winged projection is prohibited, even if recessed. I hope this answers your question. |
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ID: nht71-2.48OpenDATE: 05/12/71 FROM: AUTHOR UNAVAILABLE; L. R. Schneider; NHTSA TO: Mercedes-Benz of North America, Inc. TITLE: FMVSS INTERPRETATION TEXT: This is in reply to your letter of May 3 asking for confirmation of your understanding with Mr. Vinson of my staff that the "optical horn" lighting feature is not prohibited by paragraph S4.6(b) of Motor Vehicle Safety Standard No. 108. Paragraph S4.6(b) which states in part that "means may be provided to flash headlamps . . . for signaling purposes" allows the use of an automatic device for headlamp flashing, and it follows that a non-automatic system, such as the "optical horn" incorporates, is also permissible. |
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ID: nht71-3.1OpenDATE: 05/14/71 FROM: AUTHOR UNAVAILABLE; Douglas W. Toms; NHTSA TO: Mrs. Barbara G. Rothschild TITLE: FMVSS INTERPRETATION TEXT: This is in reply to your letter of April 28, 1971, in which you asked whether modifications to a "forced-action" belt could make it into a system that would satisfy the passive restraint requirements of Standard No. 208. Although we cannot at this time comment on the changes to which you refer, a passive belt system can be used to satisfy the requirement that protection be provided by means that require no action by vehicle occupants. As you requested, we have enclosed copies of the Standard as published March 10, 1971. |
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ID: nht72-3.17OpenDATE: 02/16/72 FROM: AUTHOR UNAVAILABLE; Richard B. Dyson; NHTSA TO: Compact Corporation TITLE: FMVSS INTERPRETATION TEXT: This is in reply to your letter of December 29, 1971, concerning the use of glazing materials in the Kangaroo Camper which your company manufactures. You ask whether Motor Vehicle Safety Standard No. 205, "Glazing Materials" (49 CFR @ 571-205) applies to this item. Because it is impossible for a person to ride in the Kangaroo camper while the vehicle is in motion, we would not consider this item to be a "camper" within the meaning of Standard No. 205, and the standard does not apply to this product. |
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ID: nht71-3.4OpenDATE: 05/17/71 FROM: AUTHOR UNAVAILABLE; Lawrence R. Schneider; NHTSA TO: Tanaka and Walders TITLE: FMVSS INTERPRETATION TEXT: This is in response to your letter of April 19, 1971, in which you discussed the difficulties that may be caused by State enforcement procedures that require a manufacturer to obtain State approval of products covered by Federal standards before he may sell the products in the State. Your letter was an amplification of the JAMA petition for reconsideration of Standard No. 209, submitted April 3, 1971. The NHTSA is giving careful consideration to the situation you have described. We intend to take action to alleviate the problem in the near future. |
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ID: nht71-4.48OpenDATE: 11/16/71 FROM: AUTHOR UNAVAILABLE; R. B. Dyson; NHTSA TO: Barber-Greene Company TITLE: FMVSS INTERPRETATION TEXT: Please forgive our delay in responding to your letter of August 27, 1971, asking if Department of Transportation safety equipment applicable to trailers is required for portable asphalt mixing machinery. It is our current position that portable asphalt mixing machinery is a "trailer" and must be equipped with the lamps and reflectors required by Motor Vehicle Safety Standard No. 108. I am enclosing a copy for your information. A temporary lighting harness is an acceptable means of conformance. Mud flaps, incidentally, are not required under the Federal motor vehicle safety standards. |
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ID: nht71-5.24OpenDATE: 12/15/71 FROM: AUTHOR UNAVAILABLE; E. T. Driver; NHTSA TO: Mobilefreeze Co., Inc. TITLE: FMVSS INTERPRETATION TEXT: This is in reply to your letter of September 7, 1971, to Mr. Stan Haransky, Truck Body and Equipment Association, Inc., concerning the mounting height of lamps and reflectors on your motor-cycle trailers. A copy of Federal Motor Vehicle Safety Standard No. 108, "Lamps, Reflective Devices and Associated Equipment" is enclosed for your information. The minimum mounting height for lamps and reflectors listed in Table IV of this Standard is 15 inches. We do not have the authority to exempt any motor vehicles from meeting these requirements. Enc. |
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ID: nht71-5.33OpenDATE: 12/27/71 FROM: R. L. CARTER -- NHTSA; SIGNATURE BY E. DRIVER TO: American Safety Belt Council TITLE: FMVSS INTERPRETATION TEXT: Thank you for your letter of December 3, 1971, regarding seat belt buckle requirements. Your interpretation that push-button buckles are not mandatory on seat belts offered for sale as replacement parts after January 1, 1972, is correct. Federal Motor Vehicle Safety Standard No. 208, Occupant Crash Protection, specifies that seat belts, installed in passenger cars after January 1, 1972, must have latch mechanisms that release by push-button action. It does not apply to replacement belts. If we can be of further assistance, please do not hesitate to contact us. |
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.