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: 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: nht94-3.48OpenTYPE: INTERPRETATION-NHTSA DATE: June 28, 1994 FROM: JE, C. H. -- Doosan Corporation, Pusan Branch (Korea) TO: Vehicle Safety Standards TITLE: MSG NO: BSI-940606 ATTACHMT: Attached To 10/12/94 Letter From Philip R. Recht To C. H. JE (A42; STD. 208) TEXT: We are one of the well-recognized Korean trading companies. This time we desire to sell automobile air bags to the states. At the same time we find out that we need a certain permission [ILLEGIBLE WORDS], for example, FMVCSS 208 from the department of transportation in the states. The highly be appreciated if you tell us what kind of standard and what other things, if necessary, are required in exporting automobile airbags in your country. We are just ready to be on the any kinds of tests required. Your prompt reply would so much be appreciated. |
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ID: nht69-2.50OpenDATE: 09/25/69 FROM: AUTHOR UNAVAILABLE; Lawrence R. Schneider; NHTSA TO: Bennett's Truck Equipment TITLE: FMVSR INTERPRETATION TEXT: This is in reply to your letter of September 10, 1969, in which you asked whether you should certify the trucks that you assemble as a manufacturer or a distributor, and what are the safety standards to which your vehicles must comply. The answer to your first question is that if you assemble the body to the chassis, you must certify as a manufacturer, regardless of by whom the body or chassis is fabricated. You should note that under the "chassis-cab ruling" (pages 43 and 369 of the enclosed regulations) the chassis-cab manufacturer is required to certify on a temporary label as to the standards to which the chassis-cab will comply when completed. In response to your second question, I am enclosing a copy of the motor vehicle standards and regulations. |
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ID: nht71-5.66OpenDATE: 12/15/71 FROM: AUTHOR UNAVAILABLE; Richard B. Dyson; NHTSA TO: Oshkosh Truck Corporation TITLE: FMVSS INTERPRETATION TEXT: This is in reply to your telegram of December 9, 1971, in which you asked whether the effective dates of Standards 206, 207, 208, and 210 are postponed to January 1, 1974 for firefighting vehicles as a result of the adoption of the effective date provisions of 49 CFR 571.8 (36 F.R. 13926, July, 28, 1971). Our answer is that since all of the amendments making the listed(Illegible Words) to trucks were issued prior to the September 1, 1971 reference date used in 571.8, these standards are effective on the dates established at the time of their issuance. Versions of Standards 208 and 210 became effective for trucks on July 1, 1971, and amended version of these standards, as well as Standards 205 and 207 become effective January 1, 1972. Sincerely, |
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ID: nht74-3.5OpenDATE: 07/09/74 FROM: P.K. KAMATH -- OSHKOSH TRUCK CORPORATION TO: RICHARD DYSON -- U.S. DEPT. OF TRANSPORTATION NATIONAL HIGHWAY TRAFFIC SAFETY ADMIN. TITLE: 49 CFR PART 571, FMVSS 101 - CONTROL LOCATION, IDENTIFICATION AND ILLUMINATION ATTACHMT: ATTACHED TO LETTER DATED 07/30/74 TO P.K. KAMATH FROM RICHARD DYSON -- NHTSA; N40-30 [ZTV]; OPINION FILE REDBOOK (-); STANDARD 101 TEXT: Dear Mr. Dyson: Oshkosh Truck Corporation, in many vehicles, incorporates two controls to stop the engine. One control designated as engine stop (electrical) is operated in normal use to shut off the engine, the other control designated as the emergency engine stop (mechanical cable) is used only in emergency to shut off the engine, should the normal engine stop fail. It is our understanding that the standard 101 applies to the control for normal engine stop and not to the emergency engine stop control. Please confirm our understanding and if you disagree, please clarify how the control is to be identified and illuminated. Very truly yours, |
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ID: nht80-1.30OpenDATE: 03/11/80 FROM: JAMES W. LAWRENCE -- MANAGER ENGINEERING RELIABILITY & GOVERNMENT STANDARDS DEPT. WHITE MOTOR CORPORATION TO: FRANK BERNDT -- CHIEF COUNSEL NATIONAL HIGHWAY TRAFFIC SAFETY ADMIN. TITLE: FMVSS-115 REQUEST FOR INTERPRETATION - S 4.5.3.3 SEQUENTIAL ASSIGNMENT OF SERIAL NUMBERS TEXT: Dear Mr. Berndt: White Motor Corporation sequentially assigns serial numbers by customer to enhance problem reporting, repair parts purchasing, vehicle licensing and defect recall. When a customer orders 50 vehicles, the attributes of which are identical, the 50 serial numbers will be sequential and assigned only to those vehicles. During the manufacturing process, if all or part of the order is cancelled, the serial numbers assigned to the unbuilt vehicles are cancelled and not reissued for any other vehicle. The remaining numbers as well as those in preceeding and subsequent customer orders are therefore sequential even though not every number is used. The preamble discussion on page 36451 of the August 17, 1978 Federal Register addressing the issue of some manufacturers desiring to keep confidential the total number of vehicles manufactured is, in our opinion, a corrolary to this condition. White believes, and requests confirmation that, the requirement for sequential assignment does not also require the use of every number in the sequence. Sincerely, |
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ID: nht75-3.45OpenDATE: 06/06/75 FROM: AUTHOR UNAVAILABLE; J. C. Schultz; NHTSA TO: TTMA TITLE: FMVSS INTERPRETATION TEXT: This responds to the Truck Trailer Manufacturers Association's May 1, 1975, request for a determination of what speed the National Highway Traffic Safety Administration (NHTSA) considers as "highway speeds" in establishing gross vehicle weight ratings (GVWR) and gross axle weight ratings (GAWR) under the requirements of 49 CFR @ 567.4 (g)(3) and (4). For purposes of GVWR-GAWR calculations, NHTSA will consider "highway speeds" to be the 60 mph value used by the United States Tire and Rim Association in assigning unqualified ratings to their tires. Therefore, trailers which are capable of speeds of 60 mph or more should be assigned ratings which reflect vehicle capabilities at 60 mph. SINCERELY, May 1, 1975 James C. Schultz Chief Counsel National Highway Traffic Safety Administration In regard to your letter of March 5, 1975, you state that "A vehicle capable of highway speeds and reasonably expected to be operated at such speeds is subject to Standard No. 121 - Air Brake Systems at weight ratings specified for highway speeds". Advice would be greatly appreciated as to the numerical value NHTSA has assigned to the term "highway speeds". Don W. Wieriman Staff Engineer-Tank Vehicles |
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ID: nht73-5.27OpenDATE: 10/18/73 FROM: AUTHOR UNAVAILABLE; R. B. Dyson for L. R. Schneider; NHTSA TO: Schultz, Evans and Burns TITLE: FMVSS INTERPRETATION TEXT: This is in reply to your letter of September 28, 1973 to Secretary Brinegar, concerning outside rear view mirrors. The existing standard (No. 111) on Rearview Mirrors, is found in Title 49, Code of Federal Regulations @ 571.111. Paragraph S3.2 establishes requirements for outside mirrors. This standard applies to all passenger cars and multipurpose passenger vehicles manufactured since January 1, 1968, and establishes requirements for original equipment mirrors. It does not apply to mirrors manufactured for the aftermarket. SINCERELY, SCHULTZ, EWAN AND BURNS September 28, 1973 Claude S. Brinegar, Secretary of Transportation Dear Sir: I am anticipating a possible suit against one of the American automotive manufacturers. The basis of this suit would be the dangerous design and manufacture of an outside side view mirror. Pursuant to the Federal Traffic and Motor Vehicle Safety Law Chapter 38 USCA @ 1392(a), your office is to establish motor vehicle safety standards. I would greatly appreciate all standards promulgated by your office pertaining to side view mirrors which were in effect for the 1973 model year. Yours truly, William C. Burns |
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ID: 2864oOpen Irving Gingold, Esq. Dear Mr. Gingold: This is in response to your letter of April 27, 1988, asking whether any of the Federal motor vehicle safety standards apply to an airport baggage conveyor. The answer is no. The National Traffic and Motor Vehicle Safety Act of 1966 ("Safety Act", 15 U.S.C. 1381 et seq.), authorizes this agency to issue safety standards applicable to new motor vehicles and certain items of motor vehicle equipment. Conversely, we have no authority to regulate vehicles that are not "motor vehicles" or equipment that is not "motor vehicle equipment." Section 102(3) of the Safety Act (15 U.S.C. 1391(3)) defines a motor vehicle as any vehicle driven or drawn by mechanical power manufactured primarily for use on the public streets, roads, and highways, except any vehicle operated exclusively on a rail or rails. Under this definition, any vehicle intended and sold solely for off-road use is not considered a motor vehicle under the Safety Act, even if it is operationally capable of highway travel. We have long offered "airport runway vehicles" as an example of vehicles that are not motor vehicles, because they are sold solely for off-road use. NHTSA has specifically stated that an airport baggage trailer is not a motor vehicle, in a July 11, 1983 letter to D.F. Landers. Since the airport baggage conveyor to which you referred in your letter is not a "motor vehicle," none of our safety standards or other regulations would apply to the vehicle. We are not aware of any other Federal agency that has established safety standards applicable to airport baggage conveyors. Sincerely,
Erika Z. Jones Chief Counsel ref:VSA#102 d:6/30/88 |
1988 |
ID: nht90-1.76OpenTYPE: INTERPRETATION-NHTSA DATE: 03/19/90 FROM: SHUICHI WATANABE -- GENERAL MANAGER AUTOMOTIVE LIGHTING ENGINEERING CONTROL DEPT. STANLEY ELECTRIC TO: ERIKA Z. JONES -- CHIEF COUNSEL DEPARTMENT OF TRANSPORTATION NATIONAL HIGHWAY TRAFFIC SAFETY ADMINISTRATION TITLE: NONE ATTACHMT: ATTACHED TO LETTER DATED 05/31/90 FROM STEPHEN P. WOOD -- NHTSA TO SUICHI WATANABE; REDBOOK A35; STANDARD 108 TEXT: We are now developing the following new combination rear lamp which we would like to know whether it is permitted under FMVSS No. 108 or not. Transformation Lamp Characteristics: In this new lamp, the color and lighted area varies as shown in the figures below. i) When tail lamp and/or stop lamp are activated, the whole lens luminous area (1, 2, 3) emits red light. When turn signal lamp is activated, the red light on the turn signal lamp area (1) disappears, and the amber light is emitted. RED RED RED --> AMBER RED RED 1 2 3 1 2 3 ii) In the same manner, when the back up lamp is activated, only the area for the back up lamp (3) changes its color from red to white. RED RED RED --> RED RED WHITE 1 2 3 1 2 3 iii) And when the turn signal lamp and reversing lamp are activated simultaneously, the turn signal lamp and back up lamp area (1 and 3) change their color as follows. RED RED RED --> AMBER RED WHITE 1 2 3 1 2 3 The requirement of photometric and lighted area for each lamp function comply to FMVSS No. 108 and related SAE Standards. As for stop and tail lamp, when 3 lamps (area 1, 2 and 3) are activated, comply to 3 compartment requirement, and when 1 lamp (area 2) is activated, complies to 1 compartment requirement of FMVSS No. 108. Kindly let us have your advice whether the above new combination rear lamp is allowed or not as soon as possible. |
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.