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: nht70-1.30OpenDATE: 01/06/70 FROM: AUTHOR UNAVAILABLE; C. A. Baker; NHTSA TO: Toyota Motor Company, Ltd. TITLE: FMVSS INTERPRETATION TEXT: Thank you for your letter of December 29, 1969, to Mr. J. E. Leysath of this Office, concerning an interpretation of paragraph S3.3 of Federal Motor Vehicle Safety Standard No. 108. The requirements and provisions of paragraph S3.3 are applicable to combinations of the required lamps, reflective devices and associated equipment as specified elsewhere in the standard. These requirements and provisions do not preclude the use of a non-required (ornamental) Class B reflex reflector in a combination rear lamp. I should also point out that effective January 1, 1970, the standard requires Class A rear reflex reflectors on all vehicles, including passenger cars. As you have proposed, such required Class A reflectors may be mounted separately from the combination rear lamp. |
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ID: nht70-1.41OpenDATE: 02/05/70 FROM: AUTHOR UNAVAILABLE; Clue D. Ferguson; NHTSA TO: G. F. Pierce Company TITLE: FMVSS INTERPRETATION TEXT: This is in reply to your letter of January 13, 1970, to Mr. W. S. Scott, and to your recent inquiry to Mr. James Gilkey, concerning your safety belt system. Federal Motor Vehicle Safety Standard No. 210 specifies the number of belt enchorages that must be provided and the performance and location requirements of these anchorages in passenger cars. This standard does not apply to seat belt assemblies. Seat belt assembly performance requirements are specified in Federal Motor Vehicle Safety Standard No. 209. I am enclosing copies of Standards Nos. 209 and 210 for your reference. Thank you for your interest in motor vehicle safety. |
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ID: 77-1.20OpenTYPE: INTERPRETATION-NHTSA DATE: 02/11/77 FROM: AUTHOR UNAVAILABLE; F. Berndt; NHTSA TO: Hon. M. C. Hatfield - U.S. Senate TITLE: FMVSS INTERPRETATION TEXT: With regard to my letter to you of July 1, 1976, concerning the application of Standard No. 120, Tire Selection and Rims for Motor Vehicles Other than Passenger Cars, to the paver manufactured by Layton Manufacturing Company of Salem, Oregon, I would like to advise you of a clarification of the requirements of the standard that may be relevant to Layton's product. Essentially, it has been clarified that the requirement of S5.1.1 of the standard accommodates a manufacturer's decision to equip its motor vehicle with tires other than "tires for highway service." This means that Layton can choose to use tires that do not conform to the requirements set forth in S5.1.1 of the standard. I have enclosed a copy of the notice that contains a detailed discussion of this clarification. |
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ID: 77-4.44OpenTYPE: INTERPRETATION-NHTSA DATE: 12/01/77 FROM: AUTHOR UNAVAILABLE; Joseph J. Levin Jr.; NHTSA TO: Texas Automobile Dealers Association TITLE: FMVSR INTERPRETATION TEXT: This responds to your October 5, 1977, letter requesting a further clarification of our interpretation given to you on September 1, 1977, concerning "kit cars." You ask whether there is a requirement to certify the vehicle if it is manufactured using an old chassis. As we stated to you in our first letter, the assembly of such a vehicle is not the manufacture of a new motor vehicle. The certification requirements of Part 567 of our regulations apply only to new motor vehicles or the alteration of previously certified vehicles prior to their first purchase for purposes other than resale. Since your remanufacturing operation constitutes neither the manufacture of a new motor vehicle nor the alteration of a previously certified vehicle, your vehicle would not be required to be certified. |
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ID: nht91-4.43OpenDATE: July 8, 1991 FROM: Charles Saunders-White TO: Steve Kratzke -- Office of Chief Counsil, NHTSA TITLE: None ATTACHMT: Attached to letter dated 8-7-91 from Paul Jackson Rice to Charles Saunders-White (A38; VSA 103) TEXT: I am building a 50's style streetrod. I am using an original manufactured body and frame from a 1929 ford roadster. The state of Wisconsin will title this car as a 'Reconstructed Vehicle'. It must conform to all 1929 state and federal laws as to required equipment. I have two questions. First, in 1929 were there any federal standards, laws, or requirements that automobiles must be equipped with: 1) Fenders, 2) Bumpers, 3) hoods, 4) Doors, 5) windshield wipers (powered or manual). My second question is, between 1920 and 1934 were there any federal laws requiring the above items on any autos in addition to my question about 1929 cars? |
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ID: nht68-2.42OpenDATE: 09/04/68 FROM: AUTHOR UNAVAILABLE; Francis Armstrong; NHTSA TO: Robert Bosch GMBR TITLE: FMVSS INTERPRETATION TEXT: Thank you for your letter of May 21, 1968, addressing to Mr. Lester D. Johnson, Commissioner of Customs, with a copy to Alan S. Boyd, Secretary of the Department of Transportation, concerning the effect of a joint Customs and Transportation regulation on replacement parts for vehicles manufactured prior to the effective date of Federal Motor Vehicle Safety Standards and particulary replacement white parking lamps. Motor Vehicle Safety Standard No. 108 specifies that the parking lamps on passenger cars, multipurpose passenger vehicles, trucks and buses of less than 80 inches overall width shall be two number, amber in color on all such vehicles manufactured after January 1, 1969. Accordingly, these specifications do not apply to the replacement parts required to keep vehicles already manufactured in safe operating condition. |
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ID: nht92-6.6OpenDATE: June 17, 1992 FROM: Mary C. Andrews TO: Legal Counsel, NHTSA TITLE: None ATTACHMT: Attached to letter dated 8/6/92 from Paul J. Rice to Mary C. Andrews (A39; Std. 125) TEXT: We are in the process of developing a new warning device for motorists to carry in their cars. It will be a 24 inch high inflatable plastic cone with reflector strips on the sides. It will be weighted down with sand in the enclosed bottom. Our question to you is would this meet with any and all restrictions the Department of Transportation has for warning devices. If you would like to see a drawing of the item, we can supply you with one. Looking forward to hearing from you in the near future. Thank you. |
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ID: 77-3.9OpenTYPE: INTERPRETATION-NHTSA DATE: 06/27/77 FROM: AUTHOR UNAVAILABLE; J. J. Levin, Jr.; NHTSA TO: Truck Body and Equipment Association, Inc. TITLE: FMVSS INTERPRETATION TEXT: This responds to your April 6, 1977, letter asking whether two proposed labels satisfy the requirements for certification and information labels found in 49 CFR Part 567. Certification, and Standard No. 120, Tire Selection and Rims for Motor Vehicles Other Than Passenger Cars. The National Highway Traffic Safety Administration (NHTSA) does not issue advance approval of compliance by manufacturers with motor vehicle safety standards or regulations. The agency, however, will give an informal opinion as to whether your sample labels appear to comply with NHTSA regulations. From the illustrations you present, it appears that you have closely followed the format suggested in our regulations, and therefore, the labels seem to comply with the agency's requirements. Section S5.3(b) of Standard No. 120 permits the use of both labels when affixed in accordance with Part 567.4(b)-(f). |
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ID: nht94-8.30OpenDATE: February 7, 1994 FROM: Martin M. Sackoff, Ph.D. -- Executive Director Of Laboratories, International Testing Laboratories TO: Office of Chief Counsil -- NHTSA TITLE: None ATTACHMT: Attached To Letter Dated 5/12/94 From John Womack To Martin Sackoff (A42; Std. 109) TEXT: Gentlemen: The subject of this request is in reference with Motor Vehicle Safety Standard No. 109 - New Pneumatic Tires - Passenger Cars. The specific question is with reference to S4.2.2.4 Tire Strength, which states "S4.2.2.4 Tire Strength. Each tire shall meet the requirements for minimum breaking energy specified in Table 1 when tested in accordance with S5.3". I shall very much appreciate receiving a reply concerning the definition or interpretation of the term "breaking" of the tire. Does this mean a blowout of the tire, or simply the breaking of the tire caused by forcing the steel plunger into the tread? Thank you. Sincerely, |
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ID: nht94-1.45OpenTYPE: INTERPRETATION-NHTSA DATE: February 7, 1994 FROM: Martin M. Sackoff, Ph.D. -- Executive Director Of Laboratories, International Testing Laboratories TO: Office of Chief Counsil -- NHTSA TITLE: None ATTACHMT: Attached To Letter Dated 5/12/94 From John Womack To Martin Sackoff (A42; Std. 109) TEXT: Gentlemen: The subject of this request is in reference with Motor Vehicle Safety Standard No. 109 - New Pneumatic Tires - Passenger Cars. The specific question is with reference to S4.2.2.4 Tire Strength, which states "S4.2.2.4 Tire Strength. Each tire shall meet the requirements for minimum breaking energy specified in Table 1 when tested in accordance with S5.3". I shall very much appreciate receiving a reply concerning the definition or interpretation of the term "breaking" of the tire. Does this mean a blowout of the tire, or simply the breaking of the tire caused by forcing the steel plunger into the tread? Thank you. Sincerely, |
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.