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: aiam3127OpenMr. G. Frinken, Manager, Automotive Engineering Europe, Uniroyal GmbH, Postfach 410, 5100 Aachen 1, West Germany; Mr. G. Frinken Manager Automotive Engineering Europe Uniroyal GmbH Postfach 410 5100 Aachen 1 West Germany; Dear Mr. Frinken: This is in response to your letter of October 12, 1979, asking whethe the character height of 5/32nds of an inch, stated in the Uniform Tire Quality Grading (UTQG) Standards (49 CFR 575.104, Figure 1), is considered by the National Highway Traffic Safety Administration (NHTSA) to specify the only acceptable height for UTQG sidewall molding, or whether the agency interprets this measurement as a minimum value.; The specification of 5/32nds of an inch tire sidewall characters wa intended by NHTSA to establish a minimum requirement to assure readability of the UTQG information presented. The agency has no objection to the use of characters of a height greater than 5/32nds of an inch, so long as all characters used to convey UTQG information are of the same height.; Sincerely, Frank Berndt, Chief Counsel |
|
ID: aiam3126OpenMr. G. Frinken, Manager, Automotive Engineering Europe, Uniroyal GmbH, Postfach 410, 5100 Aachen 1, West Germany; Mr. G. Frinken Manager Automotive Engineering Europe Uniroyal GmbH Postfach 410 5100 Aachen 1 West Germany; Dear Mr. Frinken: This is in response to your letter of October 12, 1979, asking whethe the character height of 5/32nds of an inch, stated in the Uniform Tire Quality Grading (UTQG) Standards (49 CFR 575.104, Figure 1), is considered by the National Highway Traffic Safety Administration (NHTSA) to specify the only acceptable height for UTQG sidewall molding, or whether the agency interprets this measurement as a minimum value.; The specification of 5/32nds of an inch tire sidewall characters wa intended by NHTSA to establish a minimum requirement to assure readability of the UTQG information presented. The agency has no objection to the use of characters of a height greater than 5/32nds of an inch, so long as all characters used to convey UTQG information are of the same height.; Sincerely, Frank Berndt, Chief Counsel |
|
ID: aiam1268OpenMr. Gene J. Shapiro, The Temple Building, Suite 707, Seventy- seven West Washington Street, Chicago, IL 60602; Mr. Gene J. Shapiro The Temple Building Suite 707 Seventy- seven West Washington Street Chicago IL 60602; Dear Mr. Shapiro: This is in reply to your letter of August 28, 1973, concerning Federa Motor Vehicle Safety Standard No. 218, 'Motorcycle Helmets.' You request information regarding the American National Standards Institute (ANSI) Standard Z90.1, and all existing State standards or regulations requiring the use of headgear by motorcyclists.; First, it appears you may be under the impression the Z90.1 standar and its revisions were issued by the Federal Government. This is not the case. Although the requirements of Federal Motor Vehicle Safety Standard No. 218 are largely, though not entirely, based on the Z90.1-1971 Standard published by the American National Standards Institute, the Institute is a private organization neither sponsored nor supported by the Federal Government. You will have to write to the ANSI if you want any information concerning the Z90.1 standard and its revisions.; You may obtain the existing State standards or regulations requirin the use of headgear by motorcyclists from the Department of Motor Vehicles in each State, respectively. However, it may interest you to know that any State or local requirements for the design or performance of motorcycle helmets, that have a bearing on safety, will have to be identical to the requirements of the Federal standard when the Federal standard goes into effect.; A copy of Standard No. 218 and a copy of the National Traffic and Moto Vehicle Safety Act of 1966, are enclosed for your information.; Yours truly, Richard B. Dyson, Assistant Chief Counsel |
|
ID: aiam1265OpenMr. Gene J. Shapiro, The Temple Building, Suite 707, Seventy-seven West Washington Street, Chicago, IL 60602; Mr. Gene J. Shapiro The Temple Building Suite 707 Seventy-seven West Washington Street Chicago IL 60602; Dear Mr. Shapiro: This is in reply to your letter of August 28, 1973, concerning Federa Motor Vehicle Safety Standard No. 218, 'Motorcycle Helmets.' You request information regarding the American National Standards Institute (ANSI) Standard Z90.1, and all existing State standards or regulations requiring the use of headgear by motorcyclists.; First, it appears you may be under the impression the Z90.1 standar and its revisions were issued by the Federal Government. This is not the case. Although the requirements of Federal Motor Vehicle Safety Standard No. 218 are largely, though not entirely, based on the Z90.1-1971 Standard published by the American National Standards Institute, the Institute is a private organization neither sponsored nor supported by the Federal Government. You will have to write to the ANSI if you want any information concerning the Z90.1 standard and its revisions.; You may obtain the existing State standards or regulations requirin the use of headgear by motorcyclists from the Department of Motor Vehicles in each State, respectively. However, it may interest you to know that any State or local requirements for the design or performance of motorcycle helmets, that have a bearing on safety, will have to be identical to the requirements of the Federal standard when the Federal standard goes into effect.; A copy of Standard No. 218 and a copy of the National Traffic and Moto Vehicle Safety Act of 1966, are enclosed for your information.; Yours truly, Richard B. Dyson, Assistant Chief Counsel |
|
ID: aiam3421OpenMr. Keigo Ohgiya, Executive Director, Japan Automobile Tire Manufacturers Association, Inc., 9th Floor, Toranom Building, No. 1-12, 1-Chome Toranomon, Minato-Ku, Tokyo, Japan; Mr. Keigo Ohgiya Executive Director Japan Automobile Tire Manufacturers Association Inc. 9th Floor Toranom Building No. 1-12 1-Chome Toranomon Minato-Ku Tokyo Japan; Dear Mr. Ohgiya: This responds to your recent request for an interpretation of th labeling requirements of Safety Standard No. 109 (49 CFR S571.109). Specifically, your association wants to know if Standard 109 permits tire manufacturers to include the letters 'H,' 'S,' or 'V,' as appropriate, in the tire size designation required to appear on the sidewall of passenger car tires by S4.3(a) of the Standard.; Such labeling is permitted by Standard 109. The speed rating symbol ('h,' 'S,' or 'V') established by the European Tyre and Rim Technical Organization, indicate that a tire is an acceptable high-speed tire. This permits, for example, a knowledgeable purchaser of tires for emergency vehicles to know that these tires are suitable for the higher operational speeds necessary for those vehicles. Use of these symbols in the size designation would not likely confuse the less sophisticated consumer, or otherwise defeat the purpose of the labeling information. Accordingly, use of these symbols is permitted under Standard 109.; If you have any further questions, or need further information on thi matter, please feel free to contact Steve Kratzke of my staff (202-426-2992).; Sincerely, Frank Berndt, Chief Counsel |
|
ID: aiam3841OpenJohn G. Bobak, President, Crest Industries, Inc., 3841 13th Street, Wyandolte, MI 48192; John G. Bobak President Crest Industries Inc. 3841 13th Street Wyandolte MI 48192; Dear Mr. Bobak: This responds to your letter of May 9, 1984, regarding the applicatio of Federal motor vehicle safety standard No. 212, *Windshield retention* and standard No. 216, *Roof crush resistance* to aftermarket windshield adhesives. Your specific question concerned a statement made by Kent Industries that its urethane windshield adjesive 'meets and exceeds' those two standards.; You are correct in your understanding that Standards Nos. 212 and 21 only apply to newly manufactured motor vheicles. The standards establish a certain level of performance for those vehicles and do not set specifications for such individual vehicle components as windshield adhesive. In addition, neither of these standards apply to items of motor vehicle equipment, such as windshield adhesive, sold as aftermarket products.; If you have any further questions please let me know. Sincerely, Frank Berndt, Chief Counsel |
|
ID: aiam5389Open"Mr. S. Greiff PARS Passive R ckhaltesysteme GmbH Borsigstrabe 2 63/55 Alzenau Germany"; "Mr. S. Greiff PARS Passive R ckhaltesysteme GmbH Borsigstrabe 2 63/55 Alzenau Germany"; Dear Mr. Greiff: This responds to your letter of April 19, 1994 requesting an interpretation of the 500 foot minimum runway length in the Laboratory Test Procedure for Federal motor vehicle safety standards Nos. 208, 212, 219, and 301. Laboratory Test Procedures are provided to contracted laboratories as guidelines for conducting compliance tests. The Laboratory Test Procedures do not limit the requirements of the applicable Federal motor vehicle safety standards. None of the standards referenced in your letter include any requirement for minimum runway length. Instead, the standards specify that the collision into the fixed barrier will occur at any speed up to and including 30 mph. I hope you find this information helpful. If you have any other questions, please contact Mary Versailles of my staff at this address or by phone at (202) 366-2992. Sincerely, John Womack Acting Chief Counsel; |
|
ID: aiam1149OpenMr. David J. Humphreys, RVI, Inc. Suite 406, 1140 Connecticut Avenue, Washington, DC 20006; Mr. David J. Humphreys RVI Inc. Suite 406 1140 Connecticut Avenue Washington DC 20006; Dear Mr. Humphreys: This is in reply to your letter of May 18, 1973, concerning a defec notification campaign involving furnaces manufactured by Suburban Manufacturing Company of Dayton, Tennessee, that have been used in recreational vehicles. You ask whether the obligation of the individual vehicle manufacturers under the Safety Act and applicable regulations may be met if the appropriate documents and notices are sent or filed by Suburban Manufacturing.; Suburban Manufacturing Company may prepare and submit to NHTSA or mai to purchasers, on behalf of the individual vehicle manufacturers, the information required by 49 CFR Part 573 'Defect Reports,' 49 CFR Part 577, 'Defect Notification,' and Section 113 of the Safety Act (15 U.S.C. 1402). However, the requirements must be met as they apply to manufacturers of motor vehicles, and not manufacturers of equipment. Moreover, the vehicle manufacturers themselves will still be responsible if any of the documents filed or sent by Suburban Manufacturing Company fail to fully conform to all applicable requirements.; Sincerely, Lawrence R. Schneider, Chief Counsel |
|
ID: aiam1652OpenMr. H. (Speedy) Hirai, Technical Representative, Toyo Kogyo Co., Ltd. USA, 23777 Greenfield Road, Suite 462, Southfield, MI 48075; Mr. H. (Speedy) Hirai Technical Representative Toyo Kogyo Co. Ltd. USA 23777 Greenfield Road Suite 462 Southfield MI 48075; Dear Mr. Hirai: This is in response to your letter of October 18, 1974, in which yo ask whether you must supply consumer information concerning a vehicle whose motor is modified by a high-altitude kit. Further, you wish to know whether the acceleration and passing ability tests required by the regulation must be carried out at the barometric pressure required by section 575.106(d)(1)(vi).; It is our view that you must submit consumer information that meets al the requirements of Part 575, including those relating to barometric pressure, as they apply to these vehicles. Nonetheless, this does not prohibit your also including, separate from the required information, the performance characteristics of the vehicle at the altitude for which it has been modified. While we are aware that vehicles modified for high-altitude performance might not initially be sold at low altitudes, the highly mobile nature of automobile use makes it appropriate that owners be aware of their performance at the lower altitudes at which many of them will be driven and sold after their first purchase.; Yours truly, Richard B. Dyson, Acting Chief Counsel |
|
ID: aiam1653OpenMr. H. (Speedy) Hirai, Technical Representative, Toyo Kogyo Co., Ltd. USA, 23777 Greenfield Road, Suite 462, Southfield, MI 48075; Mr. H. (Speedy) Hirai Technical Representative Toyo Kogyo Co. Ltd. USA 23777 Greenfield Road Suite 462 Southfield MI 48075; Dear Mr. Hirai: This is in response to your letter of October 18, 1974, in which yo ask whether you must supply consumer information concerning a vehicle whose motor is modified by a high-altitude kit. Further, you wish to know whether the acceleration and passing ability tests required by the regulation must be carried out at the barometric pressure required by section 575.106(d)(1)(vi).; It is our view that you must submit consumer information that meets al the requirements of Part 575, including those relating to barometric pressure, as they apply to these vehicles. Nonetheless, this does not prohibit your also including, separate from the required information, the performance characteristics of the vehicle at the altitude for which it has been modified. While we are aware that vehicles modified for high-altitude performance might not initially be sold at low altitudes, the highly mobile nature of automobile use makes it appropriate that owners be aware of their performance at the lower altitudes at which many of them will be driven and sold after their first purchase.; Yours truly, Richard B. Dyson, Acting 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.