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: nht92-1.6OpenDATE: December 29, 1992 FROM: Paul Jackson Rice -- Chief Counsel, NHTSA TO: Curtis J. Crist -- Product Development, US Marine TITLE: None ATTACHMT: Attached to letter dated 12/10/92 from Curtis J. Crist to Paul J. Rice (OCC 8136); Also attached to letter dated 10/8/76 from Frank Berndt (signature by Stephen P. Wood) to Donald I. Reed; Also attached to letter dated 12/21/77 from Joseph J. Levin, Jr. to Warren M. Heath TEXT: This responds to your letter of December 10, 1992, in which you ask for confirmation that the provisions of paragraph S4.3.1.3 of Motor Vehicle Safety Standard No. 108 relating to front side marker lamps for boat trailers remain unchanged from interpretations provided by this Office in 1976 and 1977. I am pleased to confirm that these requirements remain the same. Paragraph S4.3.1.3, however, was renumbered S5.3.1.3 several years ago. You have also asked as to what action you must take for elimination of the requirement for rear identification lamps on boat trailers 80 or more inches in overall width. You may file a petition for rulemaking requesting this change. I enclose a copy of 49 CFR Part 552, the regulation governing these petitions, which will advise you as to these procedures. Section 552.4 sets forth the information that the petition should contain, and the address to which it must be sent. |
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ID: nht94-2.49OpenTYPE: INTERPRETATION-NHTSA DATE: April 19, 1994 FROM: S. Greiff -- PARS, Passive Ruckhaltesysteme GmbH TO: Chief Counsel -- US Department of Transportation, NHTSA TITLE: None ATTACHMT: Attached To Letter Dated 6/8/94 From John Womack To S. Greiff (A42; Std. 208) TEXT: Per Fax: 001/202-366-3820 Your "Laboratory Test Procedure For FMVSS 208/212/219/301" Gentleman: PARS is a company developing occupant restraint systems for the world wide automotive industry. One of our major topics is the development of airbag systems. For development and validation of the restraint systems we own a Barrier Impact Test Facility which was built up in 1993 new. Our runway is 80 m (260 feet's) long. The velocity tolerance up to 60 kph is +/- 0.1 kph. In your Laboratory Test Procedure for FMVSS testing, a minimum runway length of 500 feet is requested. We would like to ask you for an interpretation of your "500 feet requirement". It would be much appreciated, if we could get an answer by fax. Our fax no. is: 01149/6023/942-133 Thank you very much for your efforts in advance. Sincerely yours |
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ID: nht94-2.14OpenTYPE: Interpretation-NHTSA DATE: April 1, 1994 FROM: John Womack -- Acting Chief Counsel, NHTSA TO: Eric T. Stewart -- Engineering Manager, Mid Bus (Lima, OH) TITLE: None ATTACHMT: Attached to letter dated 7/7/93 from John Womack to Thomas D. Turner; Also attached to letter dated 3/17/94 from Eric T. Stewart to Office of Chief Counsel, NHTSA (OCC 9792) TEXT: This responds to your letter of March 17, 1994, regarding a final rule published November 2, 1992 (57 FR 49413) amending Standard No. 217, Bus Emergency Exits and Window Retention and Release. You requested clarification of the width requirement in S5.5 .3(c) for retroreflective tape. You are correct that there was a discrepancy concerning the size of the tape caused by the metric conversion in the final rule. Enclosed is a copy of a July 7, 1993 letter to Mr. Thomas D. Turner of the Blue Bird Body Company which discusses this issue. As explained in that letter, we plan to issue a correction notice of the November 2, 1992 rule that would specify a minimum size of 2.5 cm for the tape. Until the correction is issued, we will not take enforcement measures regarding tape size against a manufacturer who uses 1 inch wide retroreflective tape. I hope you find this information helpful. If you have any other questions, please contact us at this address or by phone at (202) 366-2992. |
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ID: nht71-3.44OpenDATE: 07/21/71 FROM: AUTHOR UNAVAILABLE; L. R. Schneider; NHTSA TO: Peterson Manufacturing Company TITLE: FMVSS INTERPRETATION TEXT: In reply to your letter of July 9, you are correct in assuming "it will still be permissible to illuminate motorcycle license plates from the bottom even after January 1, 1973." The installation requirements of Standard No. 108, as set out in SAE Standard 587d, License Plate Lamps, March 1969, do not apply to motorcycles and motor driven cycles. |
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ID: nht71-2.41OpenDATE: 05/05/71 FROM: AUTHOR UNAVAILABLE; L. R. Schneider; NHTSA TO: Jacob P. Billig, Esq. TITLE: FMVSS INTERPRETATION TEXT: In response to your letter of April 16, 1971, it is our opinion that the placement of the 2 1/4-inch-wide orange reflex reflector striping material on motor vehicles, in the manner shown in Exhibit A of your letter, would not impair the effectiveness of lamps, reflective devices, and associated equipment required by Federal Motor Vehicle Safety Standard No. 108, and would not be prohibited by that standard. |
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ID: nht73-1.38OpenDATE: NOVEMBER 23, 1973 FROM: AUTHOR UNAVAILABLE; E. T. Driver; NHTSA TO: Mr. James C. Martin TITLE: FMVSS INTERPRETATION TEXT: This is in reply to your letter of November 9 to the U. S. Department of Transportation concerning the operation of 4-way flashers and brake lights on a 1972 Toyota. Since there is no requirement that the hazard warning signal (4-way flashers) be capable of operating independently of the stop signal, it is permissible for the stop signal to override the hazard warning signal. In fact, these signals on most passenger cars and multipurpose passenger vehicles manufactured in the United States operate similarly. |
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ID: nht71-2.9OpenDATE: 02/18/71 FROM: AUTHOR UNAVAILABLE; Rodolfo A. Diaz; NHTSA TO: Bandag Incorporated TITLE: FMVSR INTERPRETATION TEXT: This is in reply to your letter to Mr. Hartman concerning the tire identification and record keeping regulation (49 CFR Part 574) requesting that you be allowed to code by pressure chamber rather than by matrix. Since the pressure chamber is used by Bandag to serve a purpose similar to the purpose served by the matrix in hot processing of retreaded tires, you may assign(Illegible Word) numbers to your pressure chambers and use this code number in place of the matrix code number required by Part 574. |
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ID: nht90-1.47OpenTYPE: INTERPRETATION-NHTSA DATE: FEBRUARY 19, 1990 FROM: ANTHONY T. GREENISH -- U.N.D.P. TO: U.S. DEPT. OF TRANSPORTATION TITLE: NONE ATTACHMT: ATTACHED TO LETTER DATED 4-25-90 TO ANTHONY P. GREENISH FROM STEPHEN P. WOOD; (A35; PART 591) TEXT: I am presently contemplating purchasing a car in Europe and importing it when I return to the United States in July 1990. The two models I have in mind are: 1. The BMW model 324 d Diesel 2. The Honda model Accord 1.6 Ix Any information you can provide as to how these cars rate as to motor vehicle safety standards would be very welcome. |
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ID: 0596Open Mr. Michael A. Holmes Dear Mr. Holmes: This responds to your letter of December 6, 1994, to the Secretary of Transportation, regarding the laws that apply to the manufacture of cars and light trucks. You have a design which you describe as "hydrogen turbine over electric." The principal law that the Department of Transportation administers that pertains to the construction of motor vehicles is Title 49 United States Code Chapter 301 - Motor Vehicle Safety. Under its authority, we have issued the Federal Motor Vehicle Safety Standards and other pertinent regulations. These are available from the Superintendent of Documents, U.S. Government Printing Office, Washington, D.C. 20402 at an invoiced cost of around $25. The title of the volume you want is "49 CFR Parts 400-999"; all our regulations are in the 500 series. The Safety Standards are at Part 571. The applicability section of each standard informs the reader as to the types of vehicles to which it applies, such as passenger cars, motorcycles, etc. However, the standards don't differentiate between propulsion sources, and there are no standards that apply to "electric vehicles," or, in your case, "hydrogen turbine over electric." You should be aware that the Environmental Protection Agency establishes standards for motor vehicle emissions, and that the individual States are permitted to have their own standards in areas where the Department of Transportation has not acted, such as horns and fog lamps. If you have any further questions, they should be directed to this Office and we will be pleased to answer them. Sincerely,
Philip R. Recht Chief Counsel ref:571 d:1/11/95
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1995 |
ID: 11656-1PJAOpen Mr. Claude Sauvageau, P.Eng. Dear Mr. Sauvageau: This responds to your letter asking about emergency exit labeling requirements in Federal Motor Vehicle Safety Standard (FMVSS) No. 217, Bus emergency exits and window retention and release. You ask which of two labels your client, an urban bus manufacturer, should use on their emergency exit windows. As required by S5.3.1 of Standard No. 217, two motions are necessary to open the exits of your client=s buses. The first is to pull down on a red latch at the top center of the window. The second is to push to the left a handle at the bottom right of the window. Your first label depicts only the action of pulling down the red latch. Your second label shows the sequence of first pulling down the red latch and then pushing the handle to the left. You are correct in your assumption that only the second emergency exit label is permitted. The language in S5.5.1 requires the label to have A. . . the designation >Emergency exit= followed by concise operating instructions describing each motion necessary to unlatch and open the exit . . .@ (emphasis added). The word Aeach@ explains that all necessary motions have to be described. The words Aand open@ explicitly include the motion to open the window. The first label only tells how to unlatch the window, not how to open it. The second label tells how to unlatch and open the window. I hope this information is helpful. If you have any further questions, feel free to contact Paul Atelsek of my staff at 202-366-5260. Sincerely,
Samuel J. Dubbin Chief Counsel ref:217 d:4/29/96
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1996 |
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.