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: aiam2223OpenMr. John F. Evans, Wenke, Burge & Taylor, Suite 801, 1055 North Main Street, Santa Ana, CA 92701; Mr. John F. Evans Wenke Burge & Taylor Suite 801 1055 North Main Street Santa Ana CA 92701; Dear Mr. Evans: This is in response to your February 10, 1976, letter concerning th determination of Gross Vehicle Weight Rating (GVWR) and Gross Axle Weight Rating (GAWR) for boat trailers.; You have presented the following two examples: >>>GVWR -- 3300, GAWR -- 2970 and GVWR -- 3000, GAWR -- 2700. <<< Assuming that 10 percent of the trailer's loaded weight is carried b the towing vehicle, each example reflects a permissible relationship between the GVWR and the GAWR. Your letter indicates that your client presently provides a GVWR figure of 3000 pounds,; >>>based on the load carrying capacity determined when the trailer i *not* connected to a towing vehicle.<<<; If by this you mean that the boat trailer's axle system has a loa carrying capacity of 3000 pounds, then the trailer would actually be entitled to a GAWR of 3000 pounds and a GVWR of 3333 pounds. Your client is free, of course, to establish more conservative load ratings. However, the GAWR should not be less than 9/10 of the accompanying GVWR.; Yours truly, Richard B. Dyson, Assistant Chief Counsel |
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ID: aiam1128OpenMr. Jack Molesworth, Partner, Signum Plastics, 2501 Poplar Street, Oakland, CA 94607; Mr. Jack Molesworth Partner Signum Plastics 2501 Poplar Street Oakland CA 94607; Dear Mr. Molesworth: This is in reply to your letter of April 26, 1973, requesting that yo be assigned a 'DOT' code number for purposes of Motor Vehicle Safety Standard No. 205, 'Glazing Materials'. You state that you purchase acrylic plastic sheet from Thailand and Japan, and indicate that you are sole importers of this material.; Under paragraph S6 of Standard No. 205, the assignment of a code numbe is restricted to prime glazing material manufacturers, who are those manufacturers who either fabricate, laminate, or temper the glazing material. As you import only acrylic sheet, you are not a prime glazing material manufacturer, and the assignment of a code number to you is not appropriate.; I have enclosed a copy of marking requirements for glazing materials Paragraph S6.2 requires a prime glazing material manufacturer to apply a code number, which is obtained upon written request to this agency, to that glazing designed as a component of any specific motor vehicle or camper. The code number requirement does not apply to glazing sheets not designed for a specific motor vehicle or camper. If you plan to import glazing material that is designed for a specific motor vehicle or camper, the prime manufacturer of that material, whether foreign or domestic, must apply for and receive a DOT code number.; Yours truly, Richard B. Dyson, Assistant Chief counsel |
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ID: aiam0740OpenMr. R. E. Jones, Product Engineer, The Flxible Co., Loudonville, OH, 44842; Mr. R. E. Jones Product Engineer The Flxible Co. Loudonville OH 44842; Dear Mr. Jones: In reply to your letter of June 5, 1972, Motor Vehicle Safety Standar No. 302 applies only to new vehicles manufactured after September 1, 1972, and does not apply to replacement or aftermarket components.; Yours truly, Richard B. Dyson, Assistant Chief Counsel |
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ID: aiam1342OpenSheller Globe Corporation, Lima, OH; Sheller Globe Corporation Lima OH; In response to your telegram of December 6 NHTSA would consider the us of a roof emergency exit as appropriate to meet the requirements to S5.2.1 of standard No. 217 if it were impracticable to use a rear exit because, as you state, retooling an existing configuration would be excessively expensive.; Richard B. Dyson, Assistant Chief Counsel, N40-30, National Highwa Traffic Safety Administration, Department of Transportation; |
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ID: aiam1666OpenMr. George Davis, B. F. Goodrich Tire Company, 500 South Main Street, Akron, OH 44318; Mr. George Davis B. F. Goodrich Tire Company 500 South Main Street Akron OH 44318; Dear Mr. Davis: We have reviewed the draft defect notification letter delivered to u on November 12, 1974, regarding the safety-related defect in Goodrich's Space Saver Spare Tire. We find that this draft does conform to the requirements of 49 CFR Part 577, 'Defect Notification.'; Yours truly, Richard B. Dyson, Acting Chief Counsel |
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ID: aiam0563OpenMr. Norman King, Crestview Service Center, 9201 W. Pico Boulevard, Los Angeles, CA 90035; Mr. Norman King Crestview Service Center 9201 W. Pico Boulevard Los Angeles CA 90035; Dear Mr. King: This is in reply to your letter of January 7, 1972, regardin recordkeeping of tires manufactured before May 22, 1971.; Tires manufactured prior to May 22, 1971, are not subject to th recordkeeping requirements of Regulation Part 574.; Regulation Part 574 became effective May 22, 1971, for tire manufactured on and after that date.; Sincerely, E. T. Driver, Director, Office of Operating Systems, Moto Vehicle Programs; |
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ID: aiam1966OpenMs. Michelle Bolton, Cedar Park Plaza, P.O. Box 767, Cedar Park, TX 78613; Ms. Michelle Bolton Cedar Park Plaza P.O. Box 767 Cedar Park TX 78613; Dear Ms. Bolton: This is in response to your letter of June 12, 1975, concernin requirements for automobile air conditioning units, which was forwarded to this office by the Environmental Protection Agency.; We have established no requirements, general or specific, fo automobile air conditioning units. As a result, we have no material to provide you.; If you have further questions, feel free to write again. Yours truly, Richard B. Dyson, Assistant Chief Counsel |
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ID: aiam0356OpenMr. Charles J. Calvin, Managing Director, Truck Trailer Manufacturers Association, 141 K Street, N.W., Washington, DC 20006; Mr. Charles J. Calvin Managing Director Truck Trailer Manufacturers Association 141 K Street N.W. Washington DC 20006; Dear Mr. Calvin: This is in reply to your letter of May 28, 1971, requestin clarification of whether a vehicle manufacturer, under 574.10 of the Tire Identification and Record Keeping regulation, may designate someone to maintain the records for him.; This letter is to confirm that motor vehicle manufacturers may assign designee for the record keeping requirements of Part 574.; Sincerely, Lawrence R. Schneider, Acting Chief Counsel |
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ID: aiam2057OpenMr. Mike M. Simovich, President, Champ Corporation, 2500 N. Rosemond Blvd., P.O. Box 3637, EL Monte, California 91733; Mr. Mike M. Simovich President Champ Corporation 2500 N. Rosemond Blvd. P.O. Box 3637 EL Monte California 91733; Dear Mr. Simovich: I am writing in response to your July 14, 1975, letter concerning th classification of your rough terrain fork lift trucks for the purposes of the Federal motor vehicle safety standards. A copy of our September 5, 1975, letter on this subject to Congressman Danielson is enclosed. We hope it clarifies the status of your products.; Yours truly, Richard B. Dyson, Assistant Chief Counsel |
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ID: aiam1297OpenThomas N. O'Leary, Esq., Messrs. Pain & Julian, 1940 East Camelback, Phoenix, AZ 85016; Thomas N. O'Leary Esq. Messrs. Pain & Julian 1940 East Camelback Phoenix AZ 85016; Dear Mr. O'Leary: In your letter of October 8, 1973, to the Department of Transportatio you ask whether it is true that DOT requires trailer braking systems to have stainless steel conduits rather than copper ones.; Neither the Federal motor vehicle safety standards nor the regulation of the Bureau of Motor Carrier Safety contain such a requirement, and we are unaware of any Federal regulation of this nature.; 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.