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: nht75-4.47OpenDATE: 06/06/75 FROM: AUTHOR UNAVAILABLE; James C. Schultz; NHTSA TO: Department of the Army TITLE: FMVSR INTERPRETATION TEXT: This is in response to your request for a confirmation of the verbal interpretation of 49 CFR @ 571.7(c) as it applies to commercial construction equipment purchased by the military. Section 571.7(c) exempts from the Motor Vehicle Safety Standards "a vehicle or item of equipment manufactured for, and sold directly to, the Armed Forces of the United States in conformity with contractual specifications." "Motor vehicle" is defined by the National Traffic and Motor Vehicle Safety Act as: "any vehicle driven or drawn by mechanical power manufactured primarily for use on the public streets, roads, and highways . . ." (15 U.S.C. @ 102(3)). Therefore, commercial construction equipment meeting this definition which is sold to the military is exempt from the Motor Vehicle Safety Standards. SINCERELY, |
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ID: nht69-1.31OpenDATE: 01/27/69 FROM: AUTHOR UNAVAILABLE; Robert M. O'Mahoney; NHTSA TO: Nottingham & Pinto TITLE: FMVSS INTERPRETATION TEXT: This is in response to your letter of December 26, 1968, and as a follow-up of our meeting of January 9, both concerning your proposal to hot brand the legend "SECOND NOT ADJ." Over part of the brand name "ATLAS FLYORON" tires. Provided the branding of the legend does not make the brand name illegible it would be permissible under the motor vehicle safety standards. Examination of the photos you submitted indicates that no part of the brand name is obliterated and only one letter is affected, although still clearly visible. Therefore, as long as one of the methods of branding shown in the photos is followed, the labeling requirements of standard No. 109 with regard to the brand name will have been met. |
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ID: nht68-2.3OpenDATE: 06/27/68 FROM: AUTHOR UNAVAILABLE; David A. Fay; NHTSA TO: Department of Education TITLE: FMVSS INTERPRETATION TEXT: Thank you for your letter of June 4, 1968, to Mr. George C. Nield, concerning the State Board of Education's requirement for school bus warning signal lamps. The warning signal system as described in your letter does not meet the requirements of Federal Motor Vehicle Safety Standard No. 108, effective January 1, 1969. A copy of this Standard is enclosed for your reference. A minimum of four red signal lamps is required and they shall be designed to conform to SAE Standard J887, July, 1964, a copy of which is also enclosed. Four additional amber lamps are permitted. The red and amber system and the red only system shall be installed in accordance with paragraph S3.1.3.2 and S3.1.3.3, respectively, of Standard No. 108. |
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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: nht91-1.36OpenDATE: February 8, 1991 FROM: J.C. Brown -- President, MidAmerica Design Service TO: Taylor Vinson -- Chief Counsel, NHTSA TITLE: None ATTACHMT: Attached to letter dated 3-7-91 from Paul Jackson Rice to J.C. Brown (A37; Std. 108) TEXT: MidAmerica Design Service is being asked to develop a high mounted stop light and turn signal to be installed into the door of over the road trailers. This light will be wired to the existing system as an "add on". After reviewing FMV-108, I can find no reference to any high mounted stop light for trailers in any form. Therefore, it appears, that as long as I add to the existing system and not eliminate any standard lighting, we will be in compliance with the standards. Please forward to me your opinion and any other steps I must take to ensure compliance. |
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ID: nht75-1.7OpenDATE: 02/07/75 FROM: AUTHOR UNAVAILABLE; R. B. Dyson; NHTSA TO: Nissan Motor Co., Ltd. TITLE: FMVSS INTERPRETATION TEXT: N40-30 FEB 7 1975 Mr. Tatsuo Kato Staff, Safety Nissan Motor Co., Ltd. P. O. Box 1606 Englewood Cliffs, New Jersey 07632 Dear Mr. Kato: This responds to your December 18, 1974, question whether the test procedure in S7.11.2.1 of Standard No. 105-75, Hydraulic brake systems, that specifies "Accelerate immediately... after each stop" can be interpreted to permit a maximum rate of acceleration to the initial test speed of 60 mph. You also ask whether, in the case of a vehicle incapable of attaining 60 mph, the S5.1 requirement that it be tested "at the highest speed attainable in the time or distance interval specified" can also be interpreted to permit a maximum rate of acceleration. Both of these specifications permit acceleration at maximum speed. As in the case of any performance requirement, when a test procedure is not specified, a manufacturer must only "exercise due care" to assure himself that each of his vehicles meets the requirements, by selecting a reasonable test procedure to demonstrate compliance. In fact the NHTSA has consistently stated that, even when a test procedure is stated, a manufacturer may use a different procedure, so long as it is calculated, in the exercise of due care, to demonstrate that the vehicle would comply if tested in accordance with the procedure. Because the NHTSA has chosen not to specify an acceleration rate in S7.11.2.1 for fade tests, the manufacturer may reasonably choose the maximum or near maximum acceleration rate which ensures the greatest cooling effect in the brake assembly. This interpretation is also true for vehicles which are unable to attain 60 mph and must therefore reach their "highest speed" under S5.1 prior to braking. Therefore, in both cases cited, you may interpret the procedures to permit acceleration at "maximum rate" as specified in S7.11.3.1. Yours truly, Richard B. Dyson Acting Chief Counsel |
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ID: nht92-6.28OpenDATE: May 28, 1992 FROM: Steven Rovtar -- General Manager, Blazer International Corp. TO: Paul Jackson Rice -- NHTSA TITLE: None ATTACHMT: Attached to letter dated 6/17/92 from Paul J. Rice to Steven Rovtar (A39; Std. 108) TEXT: Our company, Blazer International Corp., intends to introduce a new product for the vehicle towing trailer market. Our purpose in writing is to request a written ruling that this product meets current SAE/DOT guidelines. All trailer wiring assemblies currently available require the installer to splice into the vehicle's wire harness. Blazer's new product eliminates the need for this type of hard-wiring. Our product, which is solid-state, utilizes photodetectors to read the output of the towing vehicle's stop and turn signal lamps, and in turn activate the lamps of the towed vehicle. More specifically, these photodetectors are embedded into suction cups which are attached to the towing vehicle's stop and turn signal lamps. Our device is plugged into the cigarette lighter receptacle of the towing vehicle, and the harness of the towed vehicle is plugged into our device. When the brake or turn signals of the towing vehicle are activated, the photodetectors in our device read the light emitted from the towing vehicle lamps, and the lamps on the towed vehicle are activated via the completed circuit. Your prompt response in issuing a written ruling with respect to this product will be appreciated. I can be reached at the number listed below should you have any questions or require any additional information. |
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ID: nht88-2.33OpenTYPE: INTERPRETATION-NHTSA DATE: 05/26/88 FROM: A. J. ACKLEY -- MARTEK CORP. TO: JOAN TILLGHMAN, LEGAL COUNSEL, NHTSA TITLE: NONE ATTACHMT: ATTACHED TO LETTER DATED 12/08/88 FROM ERIKA Z JONES TO A J ACKLEY; REDBOOK A33, STANDARD 125; LETTER DATED 06/10/88 FROM A J ACKLEY TO ERIKA Z JONES; OCC - 2151 TEXT: Dear Ms. Tillghman: We are in the process of submitting a proposal to an account utilizing the red safety triangle. All of the elements of the device will follow the standards as set by the D.O.C. What we propose is using their logo in the center - see drawing. This woul d revolve (to eliminate a windshield) and add to the reflective quality of the device. Do you see any legal problem with the concept? Thank you. ENCLOSURE |
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ID: nht88-2.49OpenTYPE: INTERPRETATION-NHTSA DATE: 06/10/88 FROM: A. J. ACKLEY -- MARTEK CORP. TO: ERICA Z. JONES, CHIEF COUNSEL NHTSA TITLE: NONE ATTACHMT: ATTACHED TO LETTER DATED 12/08/88 FROM ERIKA Z JONES TO A J ACKLEY; REDBOOK A33, STANDARD 125; LETTER DATED 05/26/88 FROM A. J. ACKLEY TO JOAN TILLGHAM, OCC - 2096 TEXT: Dear Ms. Jones: We are in the process of submitting a proposal to an account utilizing the red safety triangle. All of the elements of the device will follow the standards as set by the D.O.C. What we propose is using their logo in the center - see drawing. This woul d revolve (to eliminate a windshield) and add to the reflective quality of the device. Do you see any legal problem with the concept? Thank you. ENCLOSURE |
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ID: nht68-1.41OpenDATE: 06/10/68 FROM: WILLIAM HADDON -- FEDERAL HIGHWAY ADMINISTRATION TO: HARRY F. BARR -- VICE PRESIDENT ENGINEERING STAFF GENERAL MOTORS TECHNICAL CENTER GENERAL MOTORS CORPORATION TITLE: NONE TEXT: Dear Mr. Barr: The interpretations of Motor Vehicle Safety Standard No. 105 regarding cable type and bar type brake controls for driver training vehicles described in your letter of May 24 are quite correct. Motor Vehicle Safety Standard No. 105 does not apply to the installation of add-on driver training brake controls following retail sale of a new car. In the case of installation of add-on driver training brake controls in new cars prior to retail sale, the following apply: a. Motor Vehicle Safety Standard No. 105 does not apply to the add-on brake control itself; however, the installation of such controls must not affect compliance of the regular hydraulic brake system to Motor Vehicle Safety Standard No. 105. b. Following installation of a mechanical-type add-on brake control, the installing dealer is responsible for determining that compliance of the regular brake system is not impaired by verifying that the add-on control does not interfere with normal driver access to and application of the regular brake pedal. Although endorsing your understanding of the requirement imposed by Motor Vehicle Safety Standard No. 105, I am not endorsing these brake devices or passing on their safety from a crash standpoint. I appreciate your interest in driver education and training and your efforts to further traffic safety through this program. 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.