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: aiam2126OpenInterps. File, Part 575.104; Interps. File Part 575.104; Subject: Telephone call from Patrick Raher, Esq. of Hogan & Hartson Esqs., representing Mercedes-Benz, on September 15, 1975; The subject telephone call was referred to me by Mark Schwimmer. explained to the caller the status of the UTQGS litigation, the briefing schedule, and the meaning of the stay order. He stated that Mark Schwimmer had read to him the text of Judge Weick's stay order.; The caller's questions and my responses were essentially the same a those covered in my August 27, 1975 memorandum in reference to telephone calls from Yokohama Tire Company and Transportation, Inc.; From: Allan Kam, Attorney |
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ID: aiam2124OpenInterps. File, Part 575.104; Interps. File Part 575.104; Subject: Telephone call from Patrick Raher, Esq. of Hogan & Hartson Esqs., representing Mercedes-Benz, on September 15, 1975; The subject telephone call was referred to me by Mark Schwimmer. explained to the caller the status of the UTQGS litigation, the briefing schedule, and the meaning of the stay order. He stated that Mark Schwimmer had read to him the text of Judge Weick's stay order.; The caller's questions and my responses were essentially the same a those covered in my August 27, 1975 memorandum in reference to telephone calls from Yokohama Tire Company and Transportation, Inc.; From: Allan Kam, Attorney |
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ID: aiam0867OpenMr. Fred W. Cords,O.E.M. Marketing Manager,Minnesota Automotive, Inc.,Box 48/502 Patterson,Mankato,Minnesota 56001; Mr. Fred W. Cords O.E.M. Marketing Manager Minnesota Automotive Inc. Box 48/502 Patterson Mankato Minnesota 56001; Dear Mr. Cords:#This is in reply to your letter of September 19, 1972 asking whether the new hydraulic brake safety standard precludes the provision of a device using the service brake pressure to supplement normal parking brake performance.#Standard No. 105a does not prohibit the inclusion of such a device as original equipment in a motor vehicle, provided that the vehicle can meat the parking brake system requirements of the standard using the mechanical system alone.#Yours truly,Richard B. Dyson,Assistant Chief Counsel; |
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ID: aiam2485OpenMr. William Shapiro, Regulatory Analysis Engineer, Volvo of America Corporation, Rockleigh, NJ 07647; Mr. William Shapiro Regulatory Analysis Engineer Volvo of America Corporation Rockleigh NJ 07647; Dear Mr. Shapiro: This is in reply to your letter of January 4, 1977, asking fo confirmation of your interpretation that Motor Vehicle Safety Standard No. 108 permits the installation of white reflex reflectors on the front of a passenger car.; You are correct in your interpretation. While Standard No. 108 does no require any reflex reflector on the front of a passenger car, pursuant to S4.1.3 they may be added provided that they do not impair the effectiveness of the required lighting equipment.; Sincerely,Frank A. Berndt, Acting Chief Counsel |
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ID: aiam4058OpenCommander, Naval Safety Center, Naval Air Station, Norfolk, VA 23511-5796, Ref: 5100, Ser 42/5064; Commander Naval Safety Center Naval Air Station Norfolk VA 23511-5796 Ref: 5100 Ser 42/5064; Dear Commander: Thank you for your letter of December 5, 1985, following up on a numbe of phone conversations between your staff and mine, concerning the effective dates of the Federal standard requiring the installation of safety belts in motor vehicles. As requested by your staff, we have prepared the enclosed information sheet to be used as a guide by your security personnel in enforcing the safety belt use requirements on naval installations.; If you have any further questions, please let me know. Sincerely, Erika Z. Jones, Chief Counsel |
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ID: aiam2273OpenMr. L. W. Smith, President, Transportation Design & Technology, Inc., P.O. Box 28052, San Diego, CA 92128; Mr. L. W. Smith President Transportation Design & Technology Inc. P.O. Box 28052 San Diego CA 92128; Dear Mr. Smith: This responds to your November 14, 1975, request to know how th tensile strength at a joint is determined under S6.2 of Standard No. 221, *School Bus Body Joint Strength*, in the case of more than two body components joined by the same fastener.; An extensive discussion of joint strength requirements and tes procedures was recently sent to Blue Bird Body Company. Your question is addressed in that discussion and a copy is enclosed for your information.; Yours truly, Stephen Wood, Assistant Chief Counsel |
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ID: aiam3858OpenMr. M. Iwase, Manager, Technical Administration Department, Koito Mfg. Co., Ltd., Shizuoka Works, 500, Kitawaki, Shimuzu-shi, Shitzuoka-ken, Japan; Mr. M. Iwase Manager Technical Administration Department Koito Mfg. Co. Ltd. Shizuoka Works 500 Kitawaki Shimuzu-shi Shitzuoka-ken Japan; Dear Mr. Iwase: This is in reply to your letter of June 21, 1984, to Mr. Driver of thi agency asking for an interpretation of Motor Vehicle Safety Standard No. 108. Mr. Driver has not been an official of this agency for many years, and in the future, your request for interpretation should be addressed to the Chief Counsel, National Highway Traffic Safety Administration.; Your first question is whether Safety Standard No. 108 permits two-headlamp system on motorcycles. The answer is yes. Paragraph S4.1.1.34 specifies the lighting systems permissible on motorcycles. It allows two Type 2D1 or Type 2 (7 in.), or two Type 2B1 or Type 2B headlamps. Under Table IV, if two headlamps are used, they must be disposed symmetrically around the vertical center line. Two non-sealed headlamps meeting the requirements of SAE J584 may also be used, subject to the same mounting restriction. Therefore the system you propose appears acceptable under Standard No. 108.; You have also asked whether the two headlamps may be mounted one ato the other, rather than side by side. While Table IV specifies that a single headlamp must be mounted 'on the vertical centerline', it requires that two headlamps be disposed symmetrically around it. We do not interpret this language as allowing two headlamps to be mounted adjacent to each other on the vertical centerline.; Sincerely, Frank Berndt, Chief Counsel |
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ID: aiam5510OpenMr. Donnell W. Morrison 1005 Drinnon Drive Morristown, TN 37814; Mr. Donnell W. Morrison 1005 Drinnon Drive Morristown TN 37814; Dear Mr. Morrison: We have received your letter of March 14, 1995 an its attached copy of a letter dated February 14. I am sorry to say that your earlier letter never reached us. You asked whether the mounting height requirements for clearance and identification lamps (Table II of Motor Vehicle Safety Standard No. 108) have been amended to allow their mounting in locations other than 'as high as practicable.' The requirements have not changed since you were at DOT. The primary requirement is that identification lamps are to be mounted 'as close to the top of the vehicle as practicable', and that clearance lamps are mounted 'to indicate the overall width of the vehicle . . . as near the top thereof as practicable.' The determination of practicability is initially that of the manufacturer, to be made in its certification that the vehicle meets all applicable Federal motor vehicle safety standards. NHTSA will not question that determination unless it appears clearly erroneous. However, when the rear identification lamps are mounted at the extreme height of the vehicle, paragraph S5.3.1.4 states that the rear clearance lamps need not be located as close as practicable to the top of the vehicle. Further, if it is necessary to indicate the overall width of the vehicle, or for protection from damage during normal operation of the vehicle, clearance lamps may be mounted at a location other than on the front and rear and need not be visible at 45 degrees inboard (paragraph S5.3.1.1.1). Sincerely, Philip R. Recht Chief Counsel; |
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ID: aiam0484OpenMr. Harold T. Halfpenny, Halfpenny, Hahn & Roche, 111 West Washington Street, Chicago, IL, 60602; Mr. Harold T. Halfpenny Halfpenny Hahn & Roche 111 West Washington Street Chicago IL 60602; Dear Mr. Halfpenny: This is in reply to your letters of October 18, 1971, and November 1 1971, to Mr. Douglas Toms, Administrator, National Highway Traffic Safety Administration, concerning the 'Panic-Stop' signal system from Donel Corporation.; You are correct in your interpretation that Federal Motor Vehicl Safety Standard No. 108 is not applicable to the 'Panic-Stop' system when this system is not installed on motor vehicles as original equipment. The motor vehicle laws and regulations of the individual States, are, however, applicable to the 'Panic-Stop' system when sold and used as aftermarket equipment.; Sincerely, E. T. Driver, Director, Office of Operating Systems, Moto Vehicle Programs; |
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ID: aiam0612OpenMr. Sanford Davis, Urethane Industry Specialist, BASF Wyandotte Corporation, Wyandotte, MI, 48192; Mr. Sanford Davis Urethane Industry Specialist BASF Wyandotte Corporation Wyandotte MI 48192; Dear Mr. Davis: This is in reply to your letter of February 10, 1972, requesting ou comments relative to the time span over which examination might be contemplated under Motor Vehicle Safety Standard No. 302, 'Flammability of Interior Materials.'; Any vehicle to which a motor vehicle safety standard is applicable i required to conform to the standard until the vehicle has been sold to a purchaser for a purpose other than resale (15 U.S.C. S1397). In the case of Standard No. 302, the standard becomes effective September 1, 1972, and any vehicle manufactured after that date must comply until after its sale to such a purchaser.; Yours truly, Richard B. Dyson, Assistant Chief Counsel |
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.