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: nht72-3.3OpenDATE: 02/04/72 FROM: CHARLES A. BAKER FOR E.T. DRIVER -- NHTSA TO: Enterprise Sky Park TITLE: FMVSS INTERPRETATION TEXT: This is in reply to your letter of January 20, 1972, regarding standards for retreaded automobile and truck tires. Federal motor vehicle safety standards do not apply to aircraft or aircraft equipment. Standard No. 117 entitled "Retreaded Pneumatic Tires - Passenger Cars," does not apply to the retreading of aircraft tires and does not supersede Advisory Circular 43.13-1. A copy of the standard is enclosed. We do not have a safety standard for retreaded truck tires at this time. |
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ID: nht72-3.44OpenDATE: 05/12/72 FROM: AUTHOR UNAVAILABLE; Richard B. Dyson; NHTSA TO: Kangol Magnet Ltd. TITLE: FMVSS INTERPRETATION TEXT: This is in reply to your telegram of April 4, 1972, in which you asked whether it is permissible for the engine starting system of a vehicle conforming to the interlock requirements of Motor Vehicle Standard No. 208 to be operable when there are no occupants in the front seats by reaching through an open door or window to turn the ignition key. Our reply is that the standard does not prohibit a system that operates in this way. Such a system is therefore permissible. |
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ID: nht71-3.46OpenDATE: 07/21/71 FROM: AUTHOR UNAVAILABLE; Lawrence R. Schneider; NHTSA TO: Recreational Vehicle Institute, Inc. TITLE: FMVSS INTERPRETATION TEXT: This is in reply to your letter of June 22, 1971, enclosing a copy of Mr. Shrake's memorandum "Seat Belts Required by July 1, 1971", copy attached. We concur in your conclusion that the seat belt requirement does not apply to chassis-cabs, cabs, and vans, manufactured before July 1, 1971, and that, on or subsequent to that date, are completed as, or modified to become, motor homes. We concur also with the other points set out in the memorandum. ENCLOSURE |
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ID: nht71-4.46OpenDATE: 11/12/71 FROM: AUTHOR UNAVAILABLE; L. R. Schneider; NHTSA TO: Utility Trailer Manufacturing Company TITLE: FMVSS INTERPRETATION TEXT: This is in reply to your letter of October 28. We understand your apparent problem in mounting the middle identification lamp on the vertical centerline, near the extreme height of the vehicle. Since it is apparently impracticable to mount the lamps at this height, their relocation to a position under the door opening would appear to meet the requirement that identification lamps be mounted "as close as practicable to the top of the vehicle" (Table II, Standard No. 108). |
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ID: nht71-5.39OpenDATE: 09/28/71 FROM: AUTHOR UNAVAILABLE; E. T. Driver; NHTSA TO: Electric Device Corporation TITLE: FMVSS INTERPRETATION TEXT: This is in reply to your letter of September 1, 1971, to Mr. Douglas Toms, Administrator, National Highway Traffic Safety Administration, concerning your request for an interpretation relative to your safety backing system and the Federal Standards. The use of your School Bus Safety Backing System is neither required nor prohibited in Federal Motor Vehicle Safety Standard No. 108 and the proposed Pupil Transportation Safety Standard. However, it would appear that the regulations of the individual States apply to the use of your system in those States. |
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ID: nht73-3.28OpenDATE: 02/15/73 FROM: AUTHOR UNAVAILABLE; Richard B. Dyson; NHTSA TO: Mr. Charles J. Simerlein TITLE: FMVSS INTERPRETATION TEXT: This is in reply to your letter of November 29, 1972, concerning the method in which a load is to be "secured in the luggage area" under the test procedures of Standard 208. I apologize for our delay. The intent of S8.1.1(a) is to place the load in the luggage area in such a way that it stays there during the test. The standard does not specify the manner in which the load is secured. A manufacturer may secure it in any reasonable manner. |
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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: nht92-5.24OpenDATE: July 9, 1992 FROM: Tilman (Tilghman) Spingler -- Robert Bosch GmbH TO: Paul Jackson Rice -- Chief Counsel, NHTSA Administration TITLE: Request for Interpretation ATTACHMT: Attached to letter dated 8/3/92 from Paul J. Rice to Tilghman (Tilman) Spingler (A39; Std. 108) TEXT: FMVSS 108 requires for Replaceable Bulb Headlamps a vertical aim range of > +/- 4 degrees and a horizontal aim range of > +/- 2.3 degrees. Does this mean that a headlamp has to meet both ranges in addition, i.e. 2.5 degrees horizontal at a full range of 4 degrees vertical and vice-versa? Would it be possible to give me a "quick" answer by fax? |
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ID: 1982-2.8OpenDATE: 04/21/82 FROM: AUTHOR UNAVAILABLE; F. Berndt; NHTSA TO: Cosco TITLE: FMVSS INTERPRETATION TEXT: This is to follow-up on your phone conversation with Mr. Stephen Oesch of my staff concerning the application of section 5.4.3.3 and 5.4.3.4 of Standard 213, Child Restraint Systems, to harnesses. If a harness is used as a portion of child restraint system, such as a booster seat, it must comply with the requirements of S5.4.3.3. If a harness is to be used alone, without any other structure, as a child restraint system, it must comply with section 5.4.3.4 of the standard. If you have any further questions, please let me know. |
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ID: nht89-1.76OpenTYPE: INTERPRETATION-NHTSA DATE: APRIL 18, 1989 FROM: WILLIAM SHAPIRO -- MGR., PRODUCT COMPLIANCE, VOLVO CARS OF NORTH AMERICA TO: ERIKA Z. JONES -- CHIEF COUNSEL, NHTSA TITLE: REQUEST FOR INTERPRETATION, OUR LETTER JULY 11,1988 ATTACHMT: ATTACHED TO LETTER DATED 4-16-90 TO WILLIAM SHAPIRO FROM STEPHEN P. WOOD; (A35; STD. 210). ALSO ATTACHED TO LETTER DATED 7-11-88 TO ERIKA Z. JONES FROM WILLIAM SHAPIRO. TEXT: Enclosed is a copy of our July 11, 1988 letter re: FMVSS 210. We would appreciate your reply as soon as possible because our engineering department is awaiting an answer. Thank you for your attention. Enc. |
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.