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: nht69-2.37OpenDATE: 11/21/69 FROM: AUTHOR UNAVAILABLE; C. A. Baker; NHTSA TO: The Grote Manufacturing Company TITLE: FMVSS INTERPRETATION TEXT: Thank you for your letter of November 4, 1969, to Mr. J. K. Leysath of this Office concerning the flashing of side marker lamps with the turn signal lamps. The flashing of side marker lamps is permitted under paragraph S3.5 of Federal Motor Vehicle Safety Standard No. 108. Side marker lamps may be combined with turn signal lamps providing the requirements of paragraph S3.3 of MV33 No. 108 are net. |
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ID: nht68-2.35OpenDATE: 06/04/68 FROM: AUTHOR UNAVAILABLE; william H. Risteen; NHTSA TO: Clauson Manufacturing Company, Inc. TITLE: FMVSS INTERPRETATION TEXT: Your letter of May 20, 1968, to Mr. Bridwell, concerning pickup covers, has been referred to me for reply. Pickup covers which you describe are considered to be in the same category an slide-in campers and are items of motor vehicle equipment for use in motor vehicles. As such pickup covers must meet the requirements of Federal Motor Vehicle Safety Standard No. 205, Glazing Materials-Passenger Cars, Multipurpose Passenger Vehicles, Trucks, Buses and Motorcycles. |
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ID: nht71-1.2OpenDATE: 07/12/71 FROM: AUTHOR UNAVAILABLE; D. Schneider; NHTSA TO: Toyota Motor Company, Ltd. TITLE: FMVSS INTERPRETATION TEXT: This is in reply to your letter of June 9, 1971, regarding the definition of "curb weight" in Motor Vehicle Safety Standard No. 110. The air conditioner and the additional weight optional engine are to be included in "curb weight" if the motor vehicle is equipped with these items. If the motor vehicle is not so equipped, then the items are not to be included in the "curb weight" or the "accessory weight". |
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ID: nht71-1.30OpenDATE: 12/06/71 FROM: AUTHOR UNAVAILABLE; Richard B. Dyson; NHTSA TO: Auto Sun Products Company TITLE: FMVSS INTERPRETATION TEXT: This is in reply to your letter of November 16, 1971, on behalf of Kangol Magnet, Ltd., in which you requested our opinion on the number of identifying labels required on a sent belt assembly by Standard No. 209. It is our opinion that the marking requirement of that standard (S4.1(k)) is satisfied by one permanent marking or label on each assembly and that it does not require each component of an assembly to be separately marked. |
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ID: nht72-1.10OpenDATE: 10/06/72 FROM: AUTHOR UNAVAILABLE; R. B. Dyson; NHTSA TO: Minnesota Automotive, Inc. TITLE: FMVSS INTERPRETATION TEXT: This is in reply to your letter of September 19, 1972, asking whether the new hydraulic brake safety standard precludes the provision of a device using the service brake pressure to supplement normal parking brake performance. Standard No. 105a does not prohibit the inclusion of such a device as original equipment in a motor vehicle, provided that the vehicle can meet the parking brake system requirements of the standard using the mechanical system alone. |
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ID: nht72-1.37OpenDATE: 11/02/72 FROM: AUTHOR UNAVAILABLE; Richard B. Dyson; NHTSA TO: Nissan Motor Company, Ltd. TITLE: FMVSS INTERPRETATION TEXT: This is in reply to your letter of September 27, 1972, on the subject of the test procedures under Motor Vehicle Safety Standard No. 210, Seat Belt Anchorages. Your question is whether the seat belt installed in the vehicle must be used for the anchorage test. The answer is no. The standard sets requirements only for anchorages, and the seat belts are merely means by which specified forces are applied to test the anchorages. |
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ID: nht72-2.15OpenDATE: 07/11/72 FROM: AUTHOR UNAVAILABLE; R. B. Dyson; NHTSA TO: Barry Kulik TITLE: FMVSS INTERPRETATION TEXT: This is in reply to your letter of May 14, 1972, to Mr. Armstrong asking whether combination turn signal and hazard warning signal flashers conforming to Federal requirements effective January 1, 1973, may be installed in vehicles manufactured before that date. The answer is yes. Motor Vehicle Safety Standard No. 108 was amended on December 28, 1971 to allow use of flashers manufactured to conform with Standard No. 108a. I enclose a copy of the amendment for your information. |
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ID: nht71-3.3OpenDATE: 05/17/71 FROM: AUTHOR UNAVAILABLE; L. B. Schneider; NHTSA TO: Toyota Motor Company, Ltd. TITLE: FMVSS INTERPRETATION TEXT: This is in reply to your letter of April 1 seeking a clarification of paragraph S4.1.2 of Motor Vehicle Safety Standard No. 104. We confirm your understanding that S4.1.2 excludes any part of wiped areas A, B, and C that lie outside the perimeter line. Change of your driver's seating reference point to meet the proposed requirements of Standard No. 201 does not affect the percentage of area A, assuming no change in the perimeter line. |
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ID: nht71-3.36OpenDATE: 07/15/71 FROM: AUTHOR UNAVAILABLE; D. Schmeltzer for L. R. Schneider; NHTSA TO: Engine Division TITLE: FMVSS INTERPRETATION TEXT: This is in reply to your letter of June 17, 1971, concerning compliance of the Norton(Illegible Word) Commando Production Racer with the front side marker requirements of the Federal lighting standard, No. 108. It is our understanding that the racer fairing is detachable only with considerable time and effort. For all intents and purposes the fairing can be regarded as a permanent part of the vehicle and thus an appropriate place to mount the side markers. |
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ID: nht72-3.6OpenDATE: 02/01/72 FROM: AUTHOR UNAVAILABLE; E. T. Driver; NHTSA TO: Dunlop Limited TITLE: FMVSS INTERPRETATION TEXT: This will acknowledge your letter of January 14, 1972, to Mr. Douglas (Illegible Word), Administrator, National Highway Traffic Safety Administration, concerning the language of S5.1.2 of Federal Motor Vehicle Safety Standard No. 117. We concur with your comments that taken literally, the tolerance of -9% and -10% for the section width could be misinterpreted. We are placing your comments into the Docket and and editorial revision will be considered in future amendments to the standard. |
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.