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 |
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ID: nht93-5.44OpenTYPE: Interpretation-NHTSA DATE: August 2, 1993 FROM: Jane L. Dawson -- Specifications Engineer, Thomas Built Buses, Inc. TO: Charlie Hott -- NHTSA TITLE: None ATTACHMT: Attached to letter dated 2/14/94 from John Womack to Jane L. Dawson (A42; Std. 111) TEXT: As a follow-up to our recent phone conversation, please provide a written response to the following questions concerning FMVSS 111: Are we required to certify that the mirror system HAS THE ABILITY to be adjusted for viewing of the cylinders by a 25th percentile female or to certify that the mirror system HAS BEEN adjusted? Are the outside rearview mirrors required to view the area STRAIGHT DOWN from the mirrors and 200' rearward? Thanks for your cooperation. |
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ID: nht93-5.46OpenTYPE: Interpretation-NHTSA DATE: August 4, 1993 FROM: Toshi Tanaka -- General Manager, Sales & Marketing Dept., Sensor Technology Co., Ltd. TO: Delmas Johnson -- FARS Program Manager, Office of Crashworthiness Research, Research and Development, NHTSA TITLE: Ref. No. TSX-242 ATTACHMT: Attached to letter dated 11/5/93 from John Womack to Toshi Tanaka (A41; Std. 208) TEXT: Could you please let me know of the followings for our understanding on FMVSS 208? 1. Is it true that the belt fastening law now goes into a part of the federal law? 2. Is it true that the cars with airbag do not need to perform "Roll Over Test"? I am looking forward to receiving your repy by return.
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ID: nht93-7.6OpenDATE: October 1, 1993 Est. FROM: Larry Grabsky -- VML and Colonna Corp. TO: John Wilman -- Acting Chief Counsel, NHTSA TITLE: None ATTACHMT: Attached to letter dated 11/16/93 from John Womack to Larry Grabsky (A41; Std. 108) TEXT: Regarding a phone conversation with a member of your staff recently we would appreciate any relevant information pertaining to the following: Has your agency issued any recent and/or relevant advisory opinion regarding decorative neon lights or the use of oscillating or revolving lights even if they do not diminish the effect or performance of required lighting on a motor vehicle and does such violate FMVSS Section 108. Once again, we do appreciate your forwarding us information and your agencies assistance in this matter. |
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ID: nht75-1.27OpenDATE: 09/29/75 FROM: ANDREW G. DETRICH FOR ROBERT L. CARTER -- NHTSA TO: Brainerd & Bridges TITLE: FMVSS INTERPRETATION TEXT: This is in response to the May 26, 1975, petition of your client, Kugelfischer Georg Schaefer & Co., for an amendment of the banding requirement of Federal Motor Vehicle Safety Standard No. 106-74, Brake Hoses. The National Highway Traffic Safety Administration has granted the petitions of General Motors Corporation and Ford Motor Company to delete the banding requirement. A proceeding respecting the issuance of a notice of proposed rulemaking has been commenced. Because the amendment requested by your client is inconsistent with the deletion of the banding requirement, in the strict sense, that petition is hereby denied. You may find, however, that the change now being developed in our rulemaking proceedings will be satisfactory to your client. |
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ID: nht75-1.29OpenDATE: 04/29/75 FROM: AUTHOR UNAVAILABLE; R. B. Dyson; NHTSA TO: Ohio Hydraulics TITLE: FMVSS INTERPRETATION TEXT: This responds to your letter of March 7, 1975, to Mr. Francis Armstong of this agency, concerning possible changes in Federal Motor Vehicle Safety Standard No. 106-74, Brake Hoses. On March 4, 1975, the NHTSA proposed a change in the definition of "brake hose assembly" which would exclude from the standard's requirements certain assemblies made for repair of used vehicles (40 F.R. 8962, copy enclosed.) As proposed, the change would not exclude assemblies made by hose distributors. Several of the comments responding to the proposal have suggested that such distributor-made assemblies also be excluded. When a final decision is made on this issue, it will be published in the Federal Register. |
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ID: nht75-1.38OpenDATE: 09/22/75 FROM: AUTHOR UNAVAILABLE; F. Berndt; NHTSA TO: Bendix-Westinghouse TITLE: FMVSS INTERPRETATION TEXT: I am writing in response to the question you raised in a September 5, 1975, telephone conversation with Mark Schwimmer of this agency, concerning the labeling requirements of Federal Motor Vehicle Safety Standard No. 106-74, Brake Hoses. You asked whether the designation "AI & II" is permitted on air brake hose for which the Type I and Type II dimensions listed in the standard are identical. In a letter to the Gates Rubber Company (copy enclosed), the National Highway Traffic Safety Administration interpreted S7.2 of the standard as not permitting the designation "AI-II". For similar reasons, the designation "AI & II" does not comply with S7.2. The designation "AI & AII" would comply with the standard. |
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ID: nht74-4.49OpenDATE: 01/25/74 FROM: AUTHOR UNAVAILABLE; Richard B. Dyson; NHTSA TO: Dow Corning Corp. TITLE: FMVSS INTERPRETATION TEXT: This is in reply to your letter of January 10, 1974, to Mr. Schneider. It is uncertain whether "some time in July of 1974 Federal standards will become effective relating to silicone brake fluids." The proposed effective date for DOT 5 fluids is July 1, 1974, but the comments on this rulemaking action are still under consideration and the actual effective date, if the proposal is adopted, will probably be somewhat later. It is true that S5.4.3 of Standard No. 105a does not require that all reservoir labelling be "DOT 3." The letters "e.g." mean "for example." If DOT 4 is the recommended fluid then "DOT 4" would be the appropriate insertion in the required statement. |
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ID: nht95-5.5OpenTYPE: INTERPRETATION-NHTSA DATE: December 18, 1995 FROM: Tilman Spingler -- Robert Bosch GmbH TO: Samuel Dubbin -- Chief Counsel TITLE: Request for interpretation ATTACHMT: 1/29/96 letter from Samuel J. Dubbin to Tilman Spingler (A44; Std. 108) TEXT: with todays optical and mechanical methods it will be possible to achieve both high- and lowbeam of a headlamp with only one single lightsource. Are there any reservations against on the basis of the requirements in FMVSS 108? If no, which photometric requirements are applicable? Such a headlamp will in any case meet the photometric requirements for lower beam in the lower beam mode and for upper beam in the upper beam mode. The position on the vehicle is the same as for a 2-headlamp-system (e.g. wi th HB1-, HB2-, HB5-bulbs). |
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ID: nht67-1.4OpenDATE: 08/22/67 FROM: AUTHOR UNAVAILABLE; William Maddon, Jr., M.D.; NHTSA TO: The Anderson Company TITLE: FMVSS INTERPRETATION TEXT: Thank you for your letter of June 30, 1967, to Mr. Bridwell concerning windshield wiper parts. We recognize that it may be difficult to obtain reflectance values from all metal components on the windshield wiper assembly which come into the driver's field of view. For this reason, Motor Vehicle Safety Standard No. 107 includes reflectivity requirements for only the wiper arm and blade. As stated in your letter, the reflectivity of these components may be determined by using flat samples of identical material. Reflectivity requirements for the spring, rivets and other hardware items, which are attached to the wiper arm and blade, are not presently specified in Standard No. 107. |
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ID: nht69-1.47OpenDATE: 09/04/69 FROM: AUTHOR UNAVAILABLE; C. A. Baker; NHTSA TO: Department of California Highway Patrol TITLE: FMVSS INTERPRETATION TEXT: Thank you for your letters of August 12, 1969, to Dr. Robert Brenner, Acting Director, National Highway Safety Bureau, concerning visibility angles for turn-signal, stop and tall lamps on all vehicles requiring such lamps, and stop lamp operation on motorcycles. Federal Motor Vehicle Safety Standard No. 108 requires that turn signal, stop and tail lamps, upon installation on vehicles subject to the Standard, meet the 45 degree, vicibility requirements specified in SAE Standards J538d, J586c and J585c. The dual switching of stop lamps, with activation both by foot brake and hand brake on motorcycles, is required by Standard No. 108 in paragraph S3.4.4 |
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.