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: nht95-4.41OpenTYPE: INTERPRETATION-NHTSA DATE: October 1, 1995 FROM: Patrick Holmes TO: To Whom it May Concern TITLE: NONE ATTACHMT: 12/8/95 letter from Samuel J. Dubbin to Patrick Holmes (Std. 218; A43) TEXT: To whom it may concern. Due to the high cost of buying a helmet from any shops. I have decided to manufacture a helmet for my own use. What I would like to know is if I follow all specifications that the Dept. of Transportation says I must in order to certify the helmet as D.O.T. approved may I than certify my homemade helmet? I would appreciate an answer to this question at your earliest convenience. Thank you. |
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ID: nht95-7.8OpenTYPE: INTERPRETATION-NHTSA DATE: October 1, 1995 FROM: Patrick Holmes TO: To Whom it May Concern TITLE: NONE ATTACHMT: 12/8/95 letter from Samuel J. Dubbin to Patrick Holmes (Std. 218; A43) TEXT: To whom it may concern. Due to the high cost of buying a helmet from any shops. I have decided to manufacture a helmet for my own use. What I would like to know is if I follow all specifications that the Dept. of Transportation says I must in order to certify the helmet as D.O.T. approved may I than certify my homemade helmet? I would appreciate an answer to this question at your earliest convenience. Thank you. |
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ID: nht71-4.27OpenDATE: 10/22/71 FROM: AUTHOR UNAVAILABLE; L. R. Schneider; NHTSA TO: Utility Trailer Manufacturing Company TITLE: FMVSS INTERPRETATION TEXT: Thank you for your letter of September 22 asking for clarification of the requirement for spacing of rear identification lamps on trailers, as applicable to your "change number 21-23." Until January 1, 1972, Table II of Federal Motor Vehicle Safety Standard No. 108 requires that the three-lamp cluster be mounted "as close as practicable to the vertical center line." However, beginning January 1, 1972, the center lamp of the three-lamp cluster must be mounted on the vertical center line, and the offset arrangement in change number 21-23 will no longer meet the requirements of Standard No. 108. |
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ID: nht94-2.78OpenTYPE: INTERPRETATION-NHTSA DATE: May 11, 1994 FROM: William L. Blake TO: United States Department of Transportation TITLE: Re: 1985 Mercedes Benz, Model 280SL, A "Gray Model" Car ATTACHMT: Attached to Letter Dated 6/9/94 From John Womack to William L. Blake (A42; Part 581; 591; CSA S106 And Letter Dated 4/29/94 From William Blake To U.S. DOT TEXT: Gentlemen: Enclosed please find a copy of mine of April 29, 1994 to which I received no reply whatsoever. Please give me a call upon receipt of this letter and send me a reply in writing at your earliest convenience. Thank you for your cooperation. Yours very truly, Enclosure |
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ID: nht89-3.21OpenTYPE: Interpretation-NHTSA DATE: October 20, 1989 FROM: Jack E. Eanes -- Chief, Vehicles Services, State of Delaware, Department of Public Safety, Division of Motor Vehicles TO: Taylor Vinson -- Legal Counsel, NHTSA TITLE: None ATTACHMT: Attached to letter dated 7-31-90 to J. E. Eanes from P. J. Rice; (A35; Std. 205; VSA S.108(a)(2)(A) TEXT: I need a legal opinion concerning tinted rear vehicle windows which obscure the rear window mounted brake lights. Delaware law currently allows vehicle rear windows to be tinted as dark as the owner desires. In my opinion, this law might violate the federal law which mandates the rear window brake light. The light is basically unusable when the window is tinted extremely dark. |
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ID: nht94-5.43OpenDATE: May 10, 1994 FROM: Christopher A. Hart -- Acting Administrator, NHTSA; Signature by Stephen P. Wood TO: The Honorable Doug Bereuter -- U.S. House of Representatives TITLE: None ATTACHMT: Attached To Letter Dated 4/20/94 From Doug Bereuter To Christopher Hart (OCC-9916) And 1/1/94 (EST) Letter From Christopher A. Hart To Doug Bereuter TEXT: Dear Mr. Bereuter: Thank you for your recent letter concerning our rulemaking on compressed natural gas (CNG) vehicle fuel systems and fuel containers. Please be assured that I will keep you fully apprised of the rulemaking's status. I share your concern that the rulemaking be completed expeditiously as possible and appreciate your interest in this matter. Thank you for your patience. Sincerely, |
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ID: nht91-3.6OpenDATE: April 1, 1991 FROM: John Marcum -- Chairman, Electric Vehicles, S.A. TO: Administrator -- NHTSA TITLE: None ATTACHMT: Attached to letter dated 4-22-91 from Paul Jackson Rice to John Marcum (A37; VSA Sec. 108(2); Part 591); Also attached to letter dated 12-14-90 from John Marcum to Administrator, NHTSA TEXT: In reviewing our correspondence, we note that we apparently have not yet received a response to our December 14, 1990 request for a temporary exemption for the EVSA prototype electric minibus. Although the circumstances have changed somewhat since our letter, we would still appreciate your consideration of whether this exemption could be granted. I am attaching a copy of the letter for your convenience. Please let us know if you need further information. |
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ID: nht93-6.25OpenDATE: August 31, 1993 FROM: Ray Paradis -- Manufacturing Manager, Dakota Mfg. Co., Inc. TO: Pat Boyd -- NHTSA TITLE: None ATTACHMT: Attached to letter dated 11/16/93 from John Womack to Ray Paradis (A41; Std. 108) TEXT: Per our conversation concerning the reflective tape I have enclosed literature and photos of several of our trailer currently in production. Questions are as follows: (1) Deck heights are from 22" TO 39 1/2". (2) The rear design does not allow for continuous tape all models. (3) The side extension model has fold-up sides #2. (4) Does the front require any stripe. I have numbered the literature and attached photos for reference. I am looking forward to your comments. |
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ID: nht95-2.56OpenTYPE: INTERPRETATION-NHTSA DATE: April 26, 1995 FROM: John M. Quinata -- Customs And Quarantine Agency, Government Of Guam TO: Office of the Chief Counsel, NHTSA TITLE: NONE ATTACHMT: ATTACHED TO 7/25/95 LETTER FROM JOHN WOMACK TO JOHN N. QUINATA (VSA 102(3); REDBOOK 2) TEXT: Dear Sir: This is to request your assistance in determining whether or not Truck Cranes are subject to the Federal Motor Vehicle Safety Standards. Accordingly, Sanko Bussan Guam imported a used Nissan Truck Crane Lorries from Japan to off-load frozen tuna at the Port Authority of Guam. Guam Customs currently enforces the FMVSS. Enclosed is the shipping documents concerning the imported Truck Crane. Your urgent response to this matter is appreciated. (Photos and shipping documents omitted.) |
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ID: 1985-03.31OpenTYPE: INTERPRETATION-NHTSA DATE: 08/14/85 FROM: C.RICHARD FRAVEL TO: WHOM IT MAY CONCERN TITLE: RE: JOSEPH CIAMPA JR ATTACHMT: ATTACHED TO LETTER DATED 10/27/88 FROM ERIKA Z JONES TO BEVERLY B BYRON; REDBOOK A32, STANDARD 205 MEMORANDUM DATED 08/04/88 FROM ARTHUR J LOMART TO WHOM IT MAY CONCERN; LETTER DATED 08/01/88 FROM C. E. SHUE TO JOSEPH CIAMPH JR RE 0590630; LETTER DATED 09/12/88 FROM NANCY F MILLER TO BEVERLY B BYRON; LETTER DATED 08/25/88 FROM BEVERLY B BYRON TO NANCY MILLER; LETTER DATED 08/24/88 FROM JOSEPH L. CIAMPA TO BEVERLY B. BYRON TEXT: This is to state that the a boy has been my patient for many years He has severe headaches when exposed to glare of sunlight therefore a digital solution is the use of sun shade in his automobile |
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.