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: nht73-5.31OpenDATE: 10/19/73 FROM: AUTHOR UNAVAILABLE; Richard B. Dyson; NHTSA TO: Jordan Research Corporation TITLE: FMVSS INTERPRETATION TEXT: This is in reply to your letter of September 18, 1973 asking for an interpretation of Standard No. 108. You understand that "the stop lamps must light when applying the automobile brakes and/or when applying the trailer brakes individually." You tell us of a product that gives a driver "manual control of the trailer brakes [but] does not light the stop lamps in this mode." Paragraph S4.5.4 of Standard No. 108 requires that "the stop lamps on each vehicle shall be activated upon application of the service brakes." This section of Standard No. 108 requires that stop lamps on new motor vehicles be wired in this manner. The standard does not apply after the vehicle is purchased, and thus does not prohibit a vehicle owner from modifying the wiring of his vehicle by adding the Electronic Trailer Brake Control. Such an addition, however, might be precluded under State law. |
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ID: nht89-1.100Open TYPE: INTERPRETATION-NHTSA DATE: 05/17/89 FROM: ROD WILLAREDT -- DIAMOND CROSS LIGHTS TO: TAYLOR VINSON -- NHTSA TITLE: NONE ATTACHMT: ATTACHED TO LETTER DATED 06/19/89 FROM STEPHEN P. WOOD -- NHTSA TO ROD WILLAREDT; REDBOOK A33[B][2]; STANDARD 108; LETTER DATED 04/18/88 FROM ERIKA Z. JONES -- NHTSA TO WAYNE APPLE; STANDARD 108; LETTER DATED 02/19/88 FROM ERIKA Z. JONES -- NHTSA TO CHARLES WILSON -- CONGRESS; STANDARD 108; LETTER DATED 07/11/88 FROM ERIKA Z. JONES -- NHTSA TO WILLIAM J. STEPHENSON; STANDARD 108 TEXT: Dear Mr. Vinson, In reference of our phone conversation of early May, I would appreciate a letter of confirmation reguarding the D.O.T. codes and regulations concerning Diamond Cross's Safety Light. As I mentioned to you on the phone, upon my personal visitation to Washington over a year ago, I received an oral approval of the Chief Council that our safety light was not in any violation of codes or regulations. We are presently at the stage of marketing this product and have been advised that confirmation of such D.O.T. approval should be of record on file. The safety light itself shows left/right directional signals and when the caution light/emergency light appears, the formation of such lights indicates a diamond. Please note again, this safety light is an "auxiliary" truch light and does not replace any origional equipment. As time is of essence to us, I will give you a call later today to confirm receival and confirmation of written approval to follow. Thank you for your time and readiness concerning this matter. Sincerely yours, DC (trademark) Lights (c) -- 1988 P.O. Box 3696 Rapid City, SD 57709 (605) 341-2331 Rod DIAMOND CROSS(trademark), INC. Truck Safety Light (DIAGRAM OMITTED) SEE ILLUSTRATION ON ORIGINAL * Auxiliary truck light. * Increase rear end visibility by 100% * Gives an extra turn signal that is a safety feature. * Gives an extra caution signal in a diamond shape |
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ID: nht94-4.3OpenTYPE: INTERPRETATION-NHTSA DATE: August 18, 1994 FROM: John Womack -- Acting Chief Counsel, NHTSA TO: Keith E. Smith -- Piper & Marbury TITLE: None ATTACHMT: Attachment dated 5/27/94: Letter from Keith E. Smith to John G. Womack (OCC-10104) TEXT: This responds to your letter asking whether the National Highway Traffic Safety Administration (NHTSA) considers automotive and motorcycle braking systems to be "safety devices." As explained below, the agency considers such systems to be items of motor vehicle equipment. Please note that neither the National Traffic and Motor Vehicle Safety Act (formerly at 15 U.S.C. 1381 et seq. and recently codified in Title 49 of the U.S. Code) nor the agency's regulations in Title 49 of the Code of Federal Regulations use the phrase "safety device." Rather, the statute refers to "motor vehicles" and "motor vehicle equipment." Specifically, motor vehicle equipment is defined, in relevant part, as any system, part, or component of a motor vehicle as originally manufactured or any similar part or component manufactured or sold for replacement or improvement of such system, part, or component or as any accessory, or addition to the motor vehicle . . . Under this definition, NHTSA would consider an automotive or motorcycle braking system to be an item of motor vehicle equipment. Please note that the Federal motor vehicle safety standards are issued to meet the need for safety. For example, the purpose of Standard No. 105, which regulates hydraulic brake systems of passenger cars and other specified vehicles, is "to insure safe braking performance under normal and emergency conditions." See S2 of Standard No. 105. Similarly, the purpose of Standard No. 122, which regulates motorcycle brake systems, is "to insure safe motorcycle braking performance under normal and emergency co nditions." See S2 of Standard No. 122. I hope this information is helpful. If you have any further questions about NHTSA's safety standards, please feel free to contact Marvin Shaw of my staff at this address or by telephone at (202) 366-2992. |
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ID: nht93-1.3OpenDATE: January 5, 1993 FROM: Tony Stump -- Backtrack Unlimited TO: Walter Myers -- Chief Counsel's Office, NHTSA TITLE: Backtrack File # 25217; Client - Chavez ATTACHMT: Attached to letter dated 1/19/93 from Paul J. Rice to Michael Dib (A40; Part 574) TEXT: Per our conversation today please send me certified copies of the following for use in a legal matter. Please expedite this request as this information is crucial to a matter which is now in trial. A full breakdown of D.O.T. number CPFMPKD101 showing: 1. Who manufactured the tire, including full company name and address 2. When it was manufactured 3. Any additional information known about this tire Please Federal Express these certified documents for next day deliver, Federal Express account # 136638351 to: Law Office of Reid, Maguilis, and Dib Attn: Michael Dib 647 E. 4th Street Long Beach, CA 90802 If you have any questions, please call Tony Stump at: (714) 965-3207. Thank you for your prompt assistance in this matter. |
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ID: nht76-5.26OpenDATE: 11/24/76 FROM: AUTHOR UNAVAILABLE; Frank A. Bendt; NHTSA TO: HM Vehicles TITLE: FMVSR INTERPRETATION TEXT: This is in reply to your letter of October 15, 1976, to Secretary Coleman asking for copies of our regulations that would apply to a small vehicle, apparently threee-wheeled, which you intend to manufacture in limited numbers. I enclose a copy of an information sheet that tells where you may obtain copies of the Federal motor vehicle safety standards that apply to motor vehicles, and of the regulations that apply to manufacturers. I also enclose a copy of the National Traffic and Motor Vehicle Safety Act of 1966, the authority for the safety standards and regulations. If you have any questions after reviewing these materials, I will be happy to answer them for you. Three-wheeled vehicles are classified, and will be for the foreseable future, as "motorcycles." A proposed redefinition which would have removed enclosed three-wheeled vehicles from the definition is in abeyance and consideration is being given, as you suggested, to establishing standards appropriate for all lightweight motor vehicles. |
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ID: 8136Open Mr. Curtis J. Crist Dear Mr. Crist: 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. Sincerely,
Paul Jackson Rice Chief Counsel Enclosure ref:108 d.12/29/92 |
1992 |
ID: nht74-3.1OpenDATE: 07/30/74 FROM: RICHARD B. DYSON -- NHTSA ACTING CHIEF COUNSEL TO: P. K. KAMATH -- SENIOR SAFETY ENGINEER OSHKOSH TRUCK CORPORATION TITLE: N40-30 [ZTV] ATTACHMT: LETTER DATED 07/09/74 FROM P.K. KAMATH TO RICHARD DYSON -- NHTSA, 49CFR PART 571 FMVSS 101; CONTROL LOCATION, IDENTIFICATION AND ILLUMINATION TEXT: Dear Mr. Kamath: This is in reply to your letter of July 9, 1974, asking whether Standard No. 101 requires identification and illumination of an emergency engine stop control, in addition to the engine stop control intended for normal use. The "engine stop" control referred to in Standard No. 101 means any control used to stop the engine, and would include the emergency control. If it is important for the normal control to be identified and illuminated, it is all the more important that a control intended for emergency use meet the requirements of the standard. Identification such as "emergency engine stop" would be acceptable under Standard No. 101. Illumination, of course, must meet the requirements of the standard, but since you have not described the emergency system or its location we cannot offer a more precise comment. Yours truly, |
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ID: nht73-5.2OpenDATE: 08/30/73 FROM: AUTHOR UNAVAILABLE; Richard B. Dyson; NHTSA TO: Multinational Industries TITLE: FMVSS INTERPRETATION TEXT: This is in reply to your letter of July 12, 1973, concerning gas tank caps. You state that you are considering marketing imported gas tank caps for trucks, and you want to know whether there is a Federal standard to which such caps must conform. The answer is that there is not. Multinational Industries July 12, 1973 National Highway Traffic Safety Administration Attention: Chief Counsel, Lawrence Schneider We are considering the marketing of Gas Tank caps manufactured in Japan for use on trucks in the United States. As there may be some problems importing these items, I would like your opinion on the following questions: Is there any current Federal Standard to which gas tank caps must conform? If so, how is such compliance established? Must the gas tank cap bear any symbols mentioning this compliance? If so, please be specific. Thank you for your valuable time. Richard Kuskin, President |
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ID: aiam3433OpenMs. Nancy Avery, Calesco, Inc., 5620 Glenridge Drive, N.E., P.O. Box 5041, Atlanta, GA 30302; Ms. Nancy Avery Calesco Inc. 5620 Glenridge Drive N.E. P.O. Box 5041 Atlanta GA 30302; Dear Ms. Avery: This is in response to your letter of November 11, 1980, concerning th application of the Federal odometer disclosure requirements. We regret our delay in responding. The answers to your specific questions are as follows:; 1. Are we required to give the purchaser an odometer statement in th states (such as Massachusetts, Pennsylvania, and Ohio) where the mileage at the time of the vehicle transfer is recorded on the Certificate of Title?; The odometer Disclosure Requirements (49 CFR Part 580) provide that th transferor of a vehicle may substitute the state certificate of title for the Federal odometer disclosure statement, if the state title contains essentially the same information found in the Federal statement. Where the state certificate of title can be substituted for the Federal form, there is no requirement that a separate Federal odometer disclosure statement be issued to the purchaser. However, if the information contained in the state certificate of title varies from that required in the Federal form, the state must obtain the approval of this agency before its certificate of title can be used as a substitute for the Federal form.; In order to spare states the burden of an approval process, the agenc has indicated that certain variations from the Federal form are acceptable. In the *Federal Register* notice of August 1, 1977, which amended the disclosure regulation, we gave examples of shortened forms that would be acceptable. A state title can be considered to be approved for use as a full disclosure statement if it varies from the Federal form in only those aspects noted in the August 1 notice, a copy of which is enclosed.; 2. If we sell a vehicle in Canada or Puerto Rico, is this la applicable?; For purposes of the Motor Vehicle Information and Cost Savings Act, a amended, 15 U.S.C. 1901 *et seq.*, Puerto Rico is a state. Therefore, the Federal odometer disclosure requirements are applicable to the sale of a vehicle in Puerto Rico. However, the agnecy has no jurisdiction over the sale of a vehicle in Canada.; 3. On the odometer statements, is the signature of the purchase required?; The Odometer Disclosure Requirements (49 CFR Part 580.4(e)) provid that the transferee (buyer) shall acknowledge receipt of the disclosure statement by signing it.; 4. If the vehicle is sold as salvage, are we required to give th purchaser an odometer statement?; The Federal odometer disclosure laws are not applicable to vehicle that are sold for salvage. The agency has determined that for purposes of the Federal odometer laws a vehicle is salvage if it is so badly damaged that it cannot be returned to the road. However, if the vehicle is repairable and will subsequently be used as a motor vehicle, disclosure has to be made.; Sincerely, David W. Allen, Assistant Chief Counsel |
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ID: 1870yOpen AIR MAIL M. Iwase, General Manager Technical Information Dept. Koito Mfg. Co., Ltd. Shizuoka Works 500, Kitawaki Shimizu-shi, Shizuoka-ken Japan Dear Mr. Iwase: This is in reply to your letter of March 20, l989, asking for an interpretation of Motor Vehicle Safety Standard No. l08 as it applies to the location of the license plate lamp on motor vehicles. You noted the language in Tables II and IV of Standard No. l08 specifying that the lamp is to be located "at rear license plate, to illuminate the plate from the top or sides," for vehicles other than motorcycles. The requirement for motorcycles (Table IV) is simply that it be located "at rear license plate." You have asked for confirmation that, except on motorcycles, the license plate lamp shall not illuminate the plate from the bottom. Your interpretation is correct. The rationale for the requirement is that in a location other than at the bottom, the license plate lamp is less likely to be obstructed by snow or mud. I hope that this answers your question. Sincerely,
Stephen P. Wood Acting Chief Counsel / Ref:l08 d:6/l9/89 |
1970 |
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.