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: 77-1.1OpenTYPE: INTERPRETATION-NHTSA DATE: 01/12/77 FROM: AUTHOR UNAVAILABLE; Frank Berndt; NHTSA TO: Philsco Products Company, Inc. TITLE: FMVSS INTERPRETATION TEXT: This is in response to your December 27, 1976, letter concerning the effect of Federal Motor Vehicle Safety Standard No. 301-75, Fuel System Integrity, on the auxiliary fuel tanks that you manufacture for pickup trucks. The question you have asked was addressed in my November 10, 1976, letter to Mr. Charles Atkinson. It does not appear that you are in danger of going out of the auxiliary tank business. A copy of that letter is enclosed for your convenience. |
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ID: nht74-2.31OpenDATE: 02/06/74 FROM: AUTHOR UNAVAILABLE; Richard B. Dyson; NHTSA TO: Kar-Kraft, Inc. TITLE: FMVSS INTERPRETATION TEXT: This is in further reply to your letter of December 6, 1973, in response to your phone conversation with Mike Peskoe on February 25, 1974. You indicated then that our reply of February 6, 1974, failed to define "lowest seating position" as that term is used with respect to motorcycles in Motor Vehicle Safety Standard No. 205 (S5.1.2.1 and S5.1.2.2). We interpret the phrase "lowest seating position" to mean the lowest point on the uncompressed seating surface of the motorcycle operator's seat. I regret that our earlier letter omitted this information. |
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ID: nht75-1.35OpenDATE: 04/29/75 FROM: AUTHOR UNAVAILABLE; R. B. Dyson; NHTSA TO: Cummins Sales & Service Inc. TITLE: FMVSS INTERPRETATION TEXT: This responds to your letter of March 25, 1975, to Mr. Francis Armstrong of this agency, concerning the labeling requirements of Federal Motor Vehicle Safety Standard No. 106-74, Brake Hoses, as applied to brake hose assemblies. The labeling requirements for brake hose assemblies became effective on March 1, 1975. On March 4, the NHTSA proposed a change in the definition of "brake hose assembly" which would exclude certain assemblies from the requirements of the standard (40 F.R. 8962, copy enclosed.) Notice of a final decision on this proposal will be published in the Federal Register. |
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ID: nht91-6.41OpenDATE: October 25, 1991 FROM: J.W. Lawrence -- Manager, Compliance and Technical Legislation, Volvo GM Heavy Truck Corporation TO: Administrator, NHTSA TITLE: Subject: Request for Interpretation, FMVSS - 209 S4.1(f) ATTACHMT: Attached to letter dated 5/8/92 from Paul J. Rice to J.W. Lawrence (A39; Std. 209) TEXT: Volvo GM Heavy Truck requests interpretation of the subsection 4.1(f) attachment hardware requirements: "... but shall have 7/16-20 UNF 2A of 1/2-BUNC-2A attachment bolts or equivalent hardware." Does the "equivalent hardware" allow the installation of seat belts in new motor vehicles to be metric sizes and threads? Thank you. |
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ID: nht67-1.16OpenDATE: 06/19/67 FROM: AUTHOR UNAVAILABLE; G. C. Nield; NHTSA TO: S.I.C.A. Peugeot TITLE: FMVSS INTERPRETATION TEXT: Thank you for your letter of April 20, 1967, concerning the clarification of several requirements of Motor Vehicle Safety Standard No. 105. The bulb for the emergency brake system effectiveness indicator may also be used for the hand brake indicator light. Further, the means for establishing the electrical contact for testing the emergency system indicator bulb may be the hand brake lever. This clarification is not considered as a change in the requirements of the standard as issued. All characteristics required for the indicator light must be met. |
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ID: nht67-1.26OpenDATE: 12/22/67 FROM: AUTHOR UNAVAILABLE; William Haddon, Jr., M.D.; NHTSA TO: General Motors Technical Center TITLE: FMVSS INTERPRETATION TEXT: Thank you for your letter of November 13, 1967, in which approval of a dynamic inertia load test procedure, as set forth in paragraph s4.3 of Federal Motor Vehicle Safety Standard 206, was requested. This is to advise that the proposed procedure, as outlined in the enclosure to the referenced letter, is approved for the transverse inertia load portion of the standard test requirements. Thank you for your continued cooperation in achievement of our mutual goals in motor vehicle safety. |
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ID: nht67-1.8OpenDATE: 09/21/67 FROM: William Haddon, Jr., M.D.; NHTSA TO: Kurzman & Goldfarb TITLE: FMVSS INTERPRETATION TEXT: This is in reply to your letter of August 29 requesting a verification of the interpretation of Standard No. 205 contained in a letter to you dated August 10 from Max Brand of Mercedes-Benz of North America. Mr. Brands's understanding that glazing materials manufactured on or after January 1, 1968, for use in passenger cars, multipurpose passenger vehicles, motorcycles, trucks and buses must conform to Standard No. 205, but that dealer inventories of prestandard materials manufactured before January 1, 1968, may be used for replacement purposes until exhausted is correct. |
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ID: nht68-1.25OpenDATE: 04/18/68 FROM: William H. Risteen; NHTSA TO: Department of California Highway Patrol TITLE: FMVSS INTERPRETATION TEXT: This is in reply to your letters of February 15 and March 8, l968, concerning application of Federal Motor Vehicle Safety Standard Number 205. Glazing materials used in campers, pickup canopies, and covers must conform to the requirements of Federal Motor Vehicle Safety Standard Number 205. I am enclosing a copy of [Illegible Word] Ruling 68-1 published in the Federal Register, Volume 33, Number 59 on March 26, 1968, and a copy of the Federal Motor Vehicle Safety Standards (with Amendments and Interpretations through February 15, 1968). |
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ID: nht69-2.19OpenDATE: 12/02/69 FROM: AUTHOR UNAVAILABLE; R. H. Compton; NHTSA TO: Thompson Aircraft Tire Corporation TITLE: FMVSS INTERPRETATION TEXT: In response to your letter of November 6, 1969, the Department of Transporation hereby assigns number 211 to the Thompson Aircraft Tire Corporation, South San Francisco, California, as its approved code mark. The approved code mark is for use in identifying the tire manufacturer in accordance with S4.3 of the Federal Motor Vehicle Safety Standard No. 109 and the National Traffic and Motor Vehicle Act of 1966 (15 USC 1421(1)). You are cautioned that the approved code mark at the present time is for use only on new pneumatic passenger car tires. |
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ID: nht69-2.40OpenDATE: 06/30/69 FROM: C.A. BAKER -- OFFICE OF STANDARDS ON ACCIDENT AVOIDANCE, MOTOR VEH. PERFORMANCE SERV., CONCURRENCE OF OFFICE OF ASST CHIEF COUNSEL -- NHTSA TO: Renault, Incorporated TITLE: FMVSS INTERPRETATION TEXT: Thank you for your letter of June 18, 1969, to the U.S. Department of Transportation, concerning your request for clarification of the visibility requirements of back up lamps as specified in Federal Motor Vehicle Safety Standard No. 108. The visibility requirements for backup lamps on station wagons or similar type motor vehicles will be predicated on the normal driving, or closed tailgate, position. These lamps may therefore be mounted on the tailgate. |
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.