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: nht79-1.49OpenDATE: 12/14/79 FROM: AUTHOR UNAVAILABLE; F. Berndt; NHTSA TO: Automobile Importers of America, Inc. TITLE: FMVSS INTERPRETATION TEXT: This is in response to your October 29, 1979, request for an interpretation of the Federal motor vehicle safety standards. You asked whether vehicles equipped with space-saver spare tires must be tested for compliance with Federal motor vehicle safety standards with that spare tire actually used as one of the four tires mounted on the vehicle during the tests. Our interpretation is that the spare tire need not be used during those tests. This agency does not currently require that a motor vehicle be equipped with a spare tire. If a spare tire is included with the vehicle, it must, of course, comply with all standards applicable to tires. |
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ID: nht92-8.8OpenDATE: April 1, 1992 FROM: Charles Chun -- General Manager, Kia Motors TO: Paul Jackson Rice -- Chief Counsel, NHTSA TITLE: Re: S5. Dynamic Performance Requirements in FMVSS 214 - Side Impact Protection ATTACHMT: Attached to letter dated 5/22/92 from Paul J. Rice to Charles Chun (A39; Std. 214) TEXT: We would like to make clear the Manufactured Date in the captioned regulation. A) What does Manufactured Date exactly mean? Does it mean whether production date at Kia factory in Korea or the date of U.S Customs clearance ? B) Does it mean that Manufactured Date has the same meaning with the same Model Year? Appreciated your authoritative interpretation. Thank you. |
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ID: nht93-4.47OpenDATE: June 25, 1993 FROM: Ernest Farmer -- Director, Pupil Transportation, Tennessee State Department of Education, Office of Commissioner TO: Chief Counsel COPYEE: Wayne Qualls TITLE: None ATTACHMT: Attached to letter dated 7-13-93 from John Womack (signature by Stephen P. Wood) to Ernest Farmer (Std. 108; VSA 108(a)(2)(A)) TEXT: We are interested in conducting a "controlled" experiment involving a substitution of strobe lights for the traditional incandescent lights currently used in the eight light overhead warning system on school buses. Would this experiment, in your opinion, conflict with the provisions of FMVSS 108? An early reply would be appreciated since the retrofitting of these three buses (one bus in each of three school systems) is scheduled during the month of July. |
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ID: nht76-5.5OpenDATE: 11/10/76 FROM: AUTHOR UNAVAILABLE; F. Berndt; NHTSA TO: General Motors Corporation TITLE: FMVSS INTERPRETATION TEXT: This is in response to your September 14, 1976, request for confirmation that seat belt webbing with one woven selvage and one knitted selvage qualifies as "webbing", as that term is defined in paragraph S3 of Safety Standard No. 209, Seat Belt Assemblies. The definition of "webbing" in Standard No. 209 does not specify that selvages must be woven. Rather, the definition only specifies that selvages be "finished", for the purpose of ensuring that the webbing will not ravel. We conclude that the new webbing you submitted, with one woven and one knitted selvage, has "finished selvages" and would qualify as "webbing" within the meaning of Standard No. 209. |
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ID: nht74-3.26OpenDATE: 09/25/74 FROM: AUTHOR UNAVAILABLE; R. B. Dyson; NHTSA TO: O'Bannon & Gonce TITLE: FMVSS INTERPRETATION TEXT: In response to your request I have enclosed a copy of Federal Motor Vehicle Safety Standard No. 109, New Pneumatic Tires (49 CFR @ 571.109) as it appears in the current edition of the Code of Federal Regulations. The table listing load and inflation values for the G78-15 tire size designation is Table I-J of Appendix A. Except for the addition of test loads at 16 and 18 psi, the load and inflation information for the G78-15 tire size designation has not changed since the first publication of the information on April 18, 1968 (33 FR 5949), a copy of which is also enclosed. |
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ID: nht73-1.3OpenDATE: 04/05/73 FROM: R. B. Dyson; NHTSA TO: Holiday Rambler Corporation TITLE: FMVSS INTERPRETATION TEXT: This is in reply to your letter of March 20, 1973, to this agency asking about the applicability of paragraph S4.1.2 of Federal Motor Vehicle Safety Standard No. 104 to vehicles other than passenger cars. Your understanding is correct that the standard establishes wiped area requirements only for passenger car windshields. The NHTSA is engaged in research with the intent of establishing as all-weather visibility standard, combining Standards No. 103 and 104, that would among other things extend the windshield wiped area requirements to vehicles other than passenger cars. However, it is not possible to say when we will issue a rulemaking proposal on this subject. |
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ID: nht73-1.30OpenDATE: 10/25/73 FROM: E. T. Driver; NHTSA TO: Marchal America TITLE: FMVSS INTERPRETATION TEXT: This responds to your letter #8495, dated October 5, 1973 to the National Highway Traffic Safety Administration concerning the legality of an automotive headlamp having a sealed metal reflector, glass lens arrangement. It is understood from your letter that such a headlamp would meet all requirements of Federal Motor Vehicle Safety Standard No. 108, including photometric and electrical performance, interchangeability and mechanical aiming. Specifically your question is: "Would a hermetically sealed metal and glass headlamp, (one in every way interchangeable with existing approved sealed beams except that the reflector would be metal instead of glass), be acceptable under current federal regulations?" The answer to your question is "yes". |
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ID: 77-4.43OpenTYPE: INTERPRETATION-NHTSA DATE: 12/01/77 FROM: AUTHOR UNAVAILABLE; J. J. Levin, Jr.; NHTSA TO: Nissan Motor Co., Ltd. TITLE: FMVSS INTERPRETATION TEXT: This responds to your telephone conversation of November 9, 1977, with Roger Tilton of my staff concerning the applicability of the tire performance standard (Standard No. 109. New Pneumatic Tires -- Passenger Cars) to temporary-use spare tires. The National Highway Traffic Safety Administration has permitted the manufacture of temporary-use spare tires because they are smaller than regular spare tires and thus when carried in the automobile reduce its overall weight. A reduction in motor vehicle weight can result in increased fuel efficiency of the vehicle. These tires must comply with all of the safety requirements applicable to passenger car tires. |
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ID: 77-5.9OpenTYPE: INTERPRETATION-NHTSA DATE: 12/21/77 FROM: AUTHOR UNAVAILABLE; J. J. Levin, Jr.; NHTSA TO: Office of Standards Enforcement TITLE: FMVSS INTERPRETATION TEXT: I have received your November 8, 1977, memorandum questioning the applicability of the performance requirements in Section S5.4 of Standard No. 217 to knock-out rear windows. You suggest that these requirements may apply only to push-out windows, not knock-out windows. It is our interpretation that the requirements of the standard apply to both push-out and knock-out windows. We realize that this may create some difficulty for purposes of conducting compliance testing since knock-out windows must be reinstalled in order to conduct subsequent tests upon them. Nonetheless, the window should be required to comply with the standard. |
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ID: nht75-6.43OpenDATE: 10/17/75 FROM: JOHN B. WHITE -- ENGINEERING MANAGER, TECHNICAL INFORMATION DEPT., MICHELIN TIRE CORPORATION TO: MR. SCHWIMMER -- OFFICE OF THE CHIEF COUNSEL, NHTSA TITLE: NONE ATTACHMT: ATTACHED TO LETTER DATED 11-10-75 TO JOHN B. WHITE FROM FRANK A. BERNDT. TEXT: This is in regard to our telephone conversation of yesterday concerning truck tires brought into the U.S.A. to be mounted on vehicles which are to be exported outside the U.S.A. Please verify that tires imported for this purpose need not conform to FMVSS 119, Pneumatic Tires for Vehicles other than Passenger Cars or Part 574, Tire Identification and Record Keeping. This decision affects a current tire shipment, so therefore we would appreciate your prompt reply. Thank you. |
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.