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: aiam0585OpenMr. Lynn L. Saterbak, Director, Quality Control, Pyroil Company, Inc., LaCrosse, Wisconsin 54601; Mr. Lynn L. Saterbak Director Quality Control Pyroil Company Inc. LaCrosse Wisconsin 54601; Dear Mr. Saterbak: This is in reply to your letter of February 7 to Lawrence R. Schneide requesting an interpretation of Motor Vehicle Safety Standard No. 116.; No standard code numbering system has been established, and compositio of the code is at the discretion of the manufacturers and packagers of brake fluid. Note that the use of a code is optional and not a requirement of paragraph S5.2.2.2(b).; No standard format has been adopted for the serial number identifyin the package lot and date of packaging, and this information may be incorporated into one code, explainable to this agency upon our request.; Sincerely, Richard B. Dyson, Assistant Chief Counsel |
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ID: aiam0792OpenMr. J. Mulvey, Bakelite Xylonite Limited, Industrial Products Division, Brantham, Manningtree, Essex COll lNJ (sic), England; Mr. J. Mulvey Bakelite Xylonite Limited Industrial Products Division Brantham Manningtree Essex COll lNJ (sic) England; Dear Mr. Mulvey: Thank you for your letter of June 28, 1972, inquiring about th applicability of Federal Motor Vehicle Safety Standard No. 302 to safety glazing.; Safety glazing is not included in the list of motor vehicle interio materials to which Standard No. 302 applies. However, if your plastic material is used as all or part of a component of vehicle occupant compartments included under S4.1 of the standard, then, it is required to meet the requirements of Standard No. 302. A copy of this standard is enclosed for your reference.; Sincerely, Robert L. Carter, Associate Administrator, Motor Vehicl Programs; |
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ID: aiam3412OpenMr. Carol Kirk, Robinson L. P. Gas Company, R. D. No. 1, Beaver Grade Road, Coraopolis, PA 15108; Mr. Carol Kirk Robinson L. P. Gas Company R. D. No. 1 Beaver Grade Road Coraopolis PA 15108; Dear Mr. Kirk: This responds to your recent letter requesting information regardin the conversion of school bus fuel systems to dual fuel carburetion running on propane gas. Specifically, you ask whether any regulations require that a protective cage be placed around a propane fuel tank, if propane carburetion is installed on a school bus.; The answer to your specific question is no. Federal motor vehicl safety standards and regulations do not require protective cages for propane fuel tanks. In fact, the Federal safety standard regarding fuel system integrity, Standard No. 301, is not directly applicable to propane fuel systems.; I am enclosing a fact sheet for your information which discusses th Federal implications of installing auxiliary fuel tanks and of converting fuel systems to use alternate fuels. From that fact sheet you will see that there may be certain responsibilities which must be met by persons converting school buses to use dual fuel systems. Please feel free to contact Hugh Oates of my staff if you have any further questions after reviewing this information (202-426-2992).; You will have to contact your State department of motor vehicles t determine if there are any local laws or regulations which would require the installation of a protective cage around propane fuel tanks.; Sincerely, Frank Berndt, Chief Counsel |
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ID: aiam2527OpenMr. A. J. Burgess, Lucas Industries North America, Inc., Two Northfield Plaza, Troy, Michigan 48084; Mr. A. J. Burgess Lucas Industries North America Inc. Two Northfield Plaza Troy Michigan 48084; Dear Mr. Burgess: This responds to your February 4, 1977, question whether Safet Standard No. 116, *Motor Vehicle Brake Fluids*, permits DOT 3 and DOT 4 brake fluids to be colored 'fluorescent yellow.'; The answer to your question is yes. paragraph S5.1.14 of Standard No 116 specified that DOT 3 and DOT 4 fluids manufactured on or after September 1, 1978, shall be 'colorless to amber.' The agency interprets this color range to include any 'yellow,' whether or not fluorescent. Although not required, we consider fluorescence to be an added safety factor since it would facilitate the detection of leaks in the braking system.; Sincerely, Frank A. Berndt, Acting Chief Counsel |
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ID: aiam1733OpenMr. J.B. Markovich, General Manager, Utility Trailer Sales Co., Railroad and Orange Ave., P.O. Box 3258, Fresno, CA 93776; Mr. J.B. Markovich General Manager Utility Trailer Sales Co. Railroad and Orange Ave. P.O. Box 3258 Fresno CA 93776; Dear Mr. Markovich: This responds to your December 6, 1974, request for a determinatio whether a bulk transport trailer designed for transporting farm commodities from the field to processing plants over private and public roads, qualifies for exemption from Standard No. 121, *Air brake systems*, as an agricultural vehicle.; The vehicle you describe does not qualify as an agricultural vehicl that is excepted from Federal motor vehicle safety standards. The National Traffic and Motor Vehicle Safety Act of 1966 defines motor vehicle as follows:; >>>'Motor vehicle' means any vehicle driven or drawn by mechanica power manufactured primarily for use on the public streets, roads, and highways, except a vehicle operated exclusively on a rail or rails.<<<; We have interpreted this language to mean that a motor vehicle is vehicle which the manufacturer expects to be used on the public highways as part of its intended function. This would include most agricultural vehicles. However, the legislative history of the original Safety Act and S 301 indicate that congress did not intend agricultural machinery to be subject to the safety standards. We have interpreted agricultural machinery to include only vehicles designed as 'implements of husbandry' to perform strictly agricultural functions on farmland. The category does not extend to all vehicles engaged in transporting agricultural products.; The bulk transport trailer you describe appears designed expressly t rransport (sic) the product of an agricultural machine from the field to processing plants over the highways. It does not, therefore, qualify as an agricultural machine.; To expedite any questions you may have regarding the procedure fo temporary exemption, I would advise you to call Mr. Taylor Vinson of this office at (202)426-9511.; Yours truly, Richard B. Dyson, Acting Chief Counsel |
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ID: aiam2555OpenMiss Irene Glessner, 276 Birch Avenue, Elsmere Manor, Wilmington, DE 19805; Miss Irene Glessner 276 Birch Avenue Elsmere Manor Wilmington DE 19805; Dear Miss Glessner: This responds to your March 21, 1977, letter asking whether a tir dealer is required to record the serial numbers of the tires he sells.; The National Highway Traffic Safety Administration (NHTSA) promulgate regulations pertaining to tires. One of these regulations, Part 574, *Tire Identification and Recordkeeping*, requires tire dealers and distributors to obtain information when the tire is sold and to forward that information to the tire manufacturer. I am enclosing a copy of this regulation for your information. In S574.7 of the regulation you will find the exact information for which a tire dealer is responsible.; A tire dealer would not be responsible for the ultimate recall o tires. The information which a dealer submits to a manufacturer enables the manufacturer to undertake recalls. Failure to record and submit the information to a manufacturer would be a violation of Section 108 of the National Traffic and Motor Vehicle Safety Act of 1966 (as amended) (15 U.S.C. 1381, 1397). Each violation is punishable by a civil penalty of $1,000 up to a maximum of $800,000 for a series of violations (15 U.S.C. 1398).; Sincerely, Frank A. Berndt, Acting Chief Counsel |
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ID: aiam1052OpenCaptain W. F. Richardson, Adjutant, Georgia State Patrol, Post Office Box 1456, Atlanta, GA 30301; Captain W. F. Richardson Adjutant Georgia State Patrol Post Office Box 1456 Atlanta GA 30301; Dear Captain Richardson: The Department of Transportation appreciates your conscientiou response to the federal odometer disclosure regulations. The Motor Vehicle Information and Cost Savings Act requires disclosure of odometer readings, but the regulations issued to implement the Act do not require you to use a federally-printed form to make the disclosure and the government therefore does not provide such forms. The regulation specifies the information which must appear on the form executed by the transferor and is enclosed to offer an illustrative example.; Several methods would satisfy the regulation, assuming they al included the required information:; >>>(1) Stationary supply companies are printing forms and use of such separate unofficial form is satisfactory.; (2) State disclosure requirements and forms may fulfull (sic) th federal requirements or be modified to do so.; (3) Title states are encouraged to include the federal disclosur statement on title forms to cover the majority of transactions where the title accompanies the transfer.; (4) A transferor can make his own form by writing or typing th required information on a sheet of paper, signing it, and giving it to the transferee.<<<; It should be noted in conclusion that the federal government does no require a copy of this document.; Yours truly, Richard B. Dyson, Assistant Chief Counsel |
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ID: aiam2128OpenMr. James J. Schardt, Dayton Wheel Prod., Inc., 2326 E. River Road, Dayton, Ohio 45439; Mr. James J. Schardt Dayton Wheel Prod. Inc. 2326 E. River Road Dayton Ohio 45439; Dear Mr. Schardt: This is in response to your letter of August 27, 1975 (117-1) requesting an interpretation of paragraph S3 of Federal Motor Vehicle Safety Standard No. 211, *Wheel Discs, Wheel Nuts, and Hub Caps.*; Our interpretation of Standard No. 211 is that S3 prohibits winge projections that do not extend beyond the outer edge of the tire rim, as well as those that do.; We hope that this information will be of assistance. If you have an further questions, please contact us.; Sincerely, Frank A. Berndt, Acting Chief Counsel |
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ID: aiam1298OpenMr. H. Braun, Engineering Supervisor-Production, Motor Coach Industries, Inc., Pembina, ND; Mr. H. Braun Engineering Supervisor-Production Motor Coach Industries Inc. Pembina ND; Dear Mr. Braun: This is in reply to your letter of September 5, 1973, to Mr. Schneide asking whether you may furnsih (sic) side turn signal lamp for inter-city buses at the rear wheels, and if so, the required color.; It is correct that there are no Federal safety requirements for sid turn signal lamps. Therefore, there is no Federal prohibition against your providing such a lamp, and such restrictions as may exist would be those imposed by the States.; Rear mounted turn signal lamps under Federal Standard No. 108 may b either red or amber.; Yours truly, Richard B. Dyson, Assistant Chief Counsel |
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ID: aiam0249OpenMr. James S. Campbell, Engineer, International Manufacturing Company, Building 165 Industrial Park, P. O. Box 347, Benicia, California 94510; Mr. James S. Campbell Engineer International Manufacturing Company Building 165 Industrial Park P. O. Box 347 Benicia California 94510; Dear Mr. Campbell: This is in reply to your letter of August 12 to Mr. Toms requesting a interpretation of Federal Motor Vehicle Safety Standard No. 211 (Wheel Discs, Wheel Nuts, and Hub Caps).; This standard does not prohibit projections per se on wheel equipmen items, it prohibits winged projections. Thus there is no limitation on how far a cylindrical projection, for example, may extend beyond the outer edge of the tire. On the other hand, any winged projection is prohibited, even if recessed.; I hope this answers you question. Sincerely, Rodolfo A. Diaz, Acting Associate Director |
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.