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: 11393JEGOpen Dr. Aled Williams Dear Dr. Williams: This responds to your letter concerning shoes for the Hybrid III dummy. I apologize for the delay in our response. You noted that Federal Motor Vehicle Safety Standard (FMVSS) No. 208 references certain drawing numbers for the shoe specification, and asked whether there are shoes available in the U.S. which conform to these specifications. You also asked us two additional questions in the event that such shoes are not available: What shoes does NHTSA use for compliance testing, and what are the essential characteristics that should be identified for the shoes used for the Hybrid III dummy. Your questions are addressed below. By way of background, section S8.1.9.2 of FMVSS 208 specifies, for the Hybrid III dummy, that "(a) size 11EE shoe specified in drawings 78051-294 (left) and 78051-295 (right) or their equivalents is placed on each foot of the test dummy." These drawings specify gray suede leather safety shoes, size 11EE, made by Lehigh Safety Shoe Co, "or equivalent." Lehigh Safety Shoe Co. no longer makes this particular shoe. Question 1: Are there shoes available in the U.S. which conform to Standard 208's specifications? S8.1.9.2 specifies the use of the Lehigh shoe Aor equivalent.@ Although the Lehigh shoe is not available, we use an "equivalent" shoe, as further explained in answer to Question 2, below. Question 2: What shoes does NHTSA use for compliance testing? NHTSA=s Laboratory Test Procedure manual for FMVSS 208 addresses your question. Section 12.9 of the manual specifies, for both Hybrid II and Hybrid III dummies, that "(e)ach foot of the dummy shall be equipped with a size 11EE shoe which meets the configuration, size, sole, and heel thickness specifications of MIL-S-13192 and weighs 1.05 pounds to 1.45 pounds." Question 3: What are the essential characteristics that should be identified for the shoes used for the Hybrid III dummy. The dictionary defines "equivalent" as "equal in value, measure, force, effect, significance, etc." In determining whether a particular shoe is equivalent to the one specified in FMVSS 208, we consider whether use of the shoe would have any effect on the dummy readings that are used to calculate the standard's injury criteria. We have found the MIL-S-13192 shoe to be satisfactory in testing for the current injury criteria of FMVSS 208. I also note that the Society of Automotive Engineers is in the process of developing a new shoe specification for the Hybrid III dummy. After that organization completes its work, NHTSA may decide whether to incorporate that specification in FMVSS 208. I hope this information is helpful. If you have any further questions, please feel free to call Edward Glancy of my staff at (202) 366-2992. Sincerely, Samuel J. Dubbin Chief Counsel Enclosure ref:208#572 d:3/29/96
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1996 |
ID: nht79-1.50OpenDATE: 11/09/79 FROM: AUTHOR UNAVAILABLE; F. Berndt; NHTSA TO: Toyo Kogyo U.S.A. TITLE: FMVSS INTERPRETATION TEXT: This letter is in response to your October 19, 1979, request for an interpretation of the requirements of Federal Motor Vehicle Safety Standard No. 110 and 49 CFR Part 575. Specifically, you inquired if it is permissible for Mazda to place information concerning the 185SR13 tire size on the tire placard, as required by section 4.3(d) of Standard No. 110, and in the consumer information booklet, as required by 49 CFR @ 575.102(c)(2), for vehicles which may have 185HR13 tires installed by dealers at a customer's request. This would be permissible. A 185SR13 tire and a 185HR13 tire are the same size and have the same load-carrying capacity. The "S" and "H" only denote different high-speed capabilities for what are, otherwise, identical tires. This agency requires the manufacturer to list recommended tire sizes on the tire placard and in the consumer information booklet for two reasons. First, the information is required to ensure that any replacement tires installed on the vehicle will be a proper size for the rims mounted on that vehicle. Second, the information helps to ensure that the tires installed on the vehicle will have sufficient load-carrying capacity to be used safely on that particular vehicle. Neither of these safety concerns would be frustrated by a manufacturer putting information on the placard and in the booklet about a tire with a lower speed rating. Therefore, your proposed plan would not violate any of our consumer information regulations. Sincerely, ATTACH. October 19, 1979 Chief Counsel -- National Highway Traffic Safety Administration Dear Sir, RE: Request for Interpretation on MVSS 110 & Part 575 MVSS 110 Sec. 4.3 (d) requires the vehicle manufacturer's recommended tire size designation on the tire placard and also Sec. 575.102 (c)(2) requires recommended tire size designations in the consumer information booklet. One of our MAZDA models has 185SR13 as the standard tires. Currently, we are considering 185HR13 as a dealer option because some customers want a higher performance tire on their cars. We do not believe that we should put 185HR13 as the recommended tire on the tire placard, for it is a higher performance than 185SR13 and it is not installed at our factory. Please grant us your interpretation. Your earliest response would be highly appreciated. Sincerely yours, M. Ogata -- Branch Manager, TOYO KOGYO U.S.A. OFFICE |
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ID: nht74-4.39OpenDATE: 01/11/74 FROM: AUTHOR UNAVAILABLE; Richard B. Dyson; NHTSA TO: Bureau of Consumer Protection TITLE: FMVSR INTERPRETATION TEXT: Thank you for bringing the Ryder Rental odometer problem to our attention. The odometer provisions of the Motor Vehicle Information and Cost Savings Act apply only to tampering that leads to the under-representation of mileage. We recommend that over-representation cases be referred to the State consumer protection office. In this case, cf course, Mr. Sharkey registered his complaint there in the first instance. December 27, 1973 Rules Docket Odometers U.S. Department of Transportation Dear Sir: Attached is a consumer complaint alleging that the odometer on a Ryder Rental Truck was grossly deficient. Since the discrepancy was over 100 miles on a 353 mile trip, it could indicate tampering and you might wish to check into the matter further under 14 USC @ 250 and your accompanying regulations. Sincerely, David C. Keehn, Attorney, Division of Marketing Practices Mr. Stephen C. Sharkey 67 County Street Apartment 2 (Illegible Word), Masschusetts 02771 Dear Mr. Sharkey: Your letter concerning a purported overcharge on a truck rented from Ryder System, Inc., has been referred to me for reply. The Commission is currently looking into the business practices of the automobile and truck rental industry. The problem you described is among those that the staff has under consideration. As you may be aware, the Federal Trade Commission is authorized to act in the interest of the general public to require the discontinuance of unfair or deceptive practices. Our authority does not, however, extend to intervening or acting(Illegible Words) in individual cases. Accordingly, we regret that we cannot be of direst assistance to you in this matter. Nonetheless, your complaint will be added to the pending file, and such action will be taken as is warranted by the public interest. To resolve your difficulties, you may wish to communicate directly with the company. If so, you should write to Mr. James A. Ryder, Chairman of the board, Ryder System, Inc., 2701 South Bayshore Drive, Miami, Florida 33133. A copy of your letter to Mr. Ryder may be sent to Darian B. Andersen, Esquire, Law Department, Ryder System, Inc., 3600 N.W. 82nd Avenue, Miami, Florida 33166. For your reference, we have enclosed a copy of your original letter to us. Thank you for bringing this matter to the Commission's attention. Sincerely yours, Alan N. Schlaifer Attorney Division of Marketing Practices |
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ID: nht81-2.32OpenDATE: 06/09/81 FROM: AUTHOR UNAVAILABLE; Frank Berndt; NHTSA TO: Robinson L. P. Gas Company TITLE: FMVSS INTERPRETATION TEXT: This responds to your recent letter requesting information regarding 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 vehicle 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 the 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 to determine if there are any local laws or regulations which would require the installation of a protective cage around propane fuel tanks. SINCERELY May 12, 1981 National Highway Traffic Safety Administration Attn: Roger Tilton Legal Counsel I recently had a conversation with Billie Renyolds, Executive Director of the National School Transportation Association and she directed me to your office for information regarding the conversion of school buses to dual fuel carburetion running on propane fuel. More specifically, I am interested in finding if the application of a cage around a propane tank is necessary for installation of propane carburetion on school buses. There has been much controversy regarding this subject during the past year. Because Robinson L. P. Gas Company will be converting school buses to propane, we, of course, are very interested in knowing what the proper procedures should be according to state and federal codes. As of this date, all propane conversions done in the state of Pennsylvania have not had a cage around the fuel tank. The tanks have been installed according to Pamphlet 58 and we are using ASME motot fuel 312 PSI tanks. Thank you for your consideration. I will be looking forward to your reply in the near future. Carol Kirk Marketing Representative CC: RICHARD C. MARTIN -- ROBINSON L. P. GAS CO. |
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ID: nht75-5.22OpenDATE: 12/12/75 FROM: AUTHOR UNAVAILABLE; Mark I. Schwimmer; NHTSA TO: INTERPRETATIONS FILE; PARTS 575.104(d)(1)(ii) and 575.6 TITLE: FMVSR INTERPRETATION TEXT: Office visit by Pat Raber, Hogan and Hartson I received in office visit on December 8, 1973, from Mr. Raher of Hogan and Hartson (representing Mercedes-Benz). He showed me a sample information sheet of the type that Mercedes proposes to use to indicate the quality grades of tires with which its vehicles are equipped. We discussed the vehicle manufacturer's information requirement of the Uniform Tire Quality Grading Standards, and I indicated that a formal interpretation would follow our receipt of his letter, which is en route. |
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ID: coachmen2.ztvOpenMs. Kathy L. Samovitz Dear Ms. Samovitz: This is in reply to your e-mail of March 18, 2003, to Jonathan White of this agency, with regard to reporting of field reports under the early warning reporting regulation promulgated by the National Highway Traffic Safety Administration (Subpart C of 49 CFR Part 579). You asked whether "prior authorization submissions for warranty repairs fall into the category of field reports."If we conclude that these submissions are "field reports," you asserted that it would be "an incredible burden on each manufacturer to capture the historical information for the last ten model years" if it were required to include prior authorization submissions in the count of field reports. In an e-mail to Taylor Vinson of this Office on April 9, 2003, you described a "prior authorization submission" as follows:
As we understand your concern, if the dealers submission is considered a field report and the dealer later submits a warranty claim relating to it, there will be duplicate reporting of numbers under field reports and warranty claims. On the other hand, if the submission is not considered a field report and the manufacturer denies the submission, the information will not result in a warranty claim and could go uncaptured. In developing the early warning reporting requirements, we were not aware of documents called "prior authorization submissions" and, thus, did not develop a definition for this term. Your letter implies that other manufacturers may have similar "prior approval" documents, but, in the absence of a definition or generally accepted meaning of the term, the format of such a submission may vary from manufacturer to manufacturer in terms of its informational content. While such a document may appear to have some elements of a "field report," it apparently simply identifies the problem as a foundation for a warranty claim, and the action item sought is simply a warranty authorization. If the manufacturer approves the authorization, the incident will be reflected subsequently in the manufacturers quarterly report on warranty claims. We believe that this serves the purpose of early warning reporting. However, if the document contained an assessment of a performance problem to the manufacturer and was not oriented primarily toward warranty approval, it would be considered to be a field report. If you have any questions, you may phone Taylor Vinson of this Office (202-366-5263). Sincerely, Lloyd S. Guerci ref:579 |
2003 |
ID: nht71-1.46OpenDATE: 01/01/71 EST FROM: AUTHOR UNAVAILABLE; L. R. Schneider; NHTSA TO: L. R. Walders, Esq. TITLE: FMVSS INTERPRETATION TEXT: RE: REQUEST FOR INTERPRETATION OF FMVSS NO. 108 In your letter of December 23, 1970, you asked on behalf of the Japan Automobile Manufacturer's Association whether a motorcycle manufactured prior to January 1, 1973, must comply with the location requirements for turn signal lamps if the vehicle is so equipped. This will confirm your interpretation that "the location requirements for turn signal lamps do not apply to motorcycles manufactured before January 1, 197, and no change would be required for the location of turn signal lamps on motorcycles manufactured before that date". |
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ID: nht76-5.68OpenDATE: 12/28/76 FROM: CHARLES A. BAKER FOR E. T. DRIVER -- NHTSA TO: Tucker; Gray and Thigpen TITLE: FMVSR INTERPRETATION TEXT: This is in reply to your letter of October 4, 1976, requesting data on the Gateway Gumbo Wide Mudder tire involved in an automobile accident that you are investigating. From your correspondence, you indicate that the tire was manufactured by the Denman Rubber Company and that Dunlap Kyle of Batesville, Mississippi owns the engineering specifications or blueprints. As this statement suggests a variation from usual tire industry practice, we did some investigating of our records. Our records indicate that there is a retreading plant operated by Dunlap and Kyle Company, P. O. Box 689, Batesville, Mississippi, for the retreading of light truck-type tires. Therefore, before we can answer your letter, we need some additional information. Please forward to us the tire identification number of the tire as this will help determine if, in fact, this is a retreaded tire. This number will be located near the symbol DOT, and if it is a retreaded tire, should be located near the shoulder of the tire and not near the bead. SINCERELY, TUCKER, GRAY AND THIGPEN ATTORNEYS AT LAW October 4, 1976 U. S. Department of Transportation National Highway Traffic Safety Administration I am investigating an automobile accident, the cause of which has been attributed to the failure of the following described tire: Gateway -- Gumbo Wide Mudder 12-15LT 6 Ply Rating 4 Ply Nylon Cord Tubeless Load Range C Max. Load 2,850 pounds at Max. inflation 42 P.S.I Cold It is my understanding that this tire is manufactured by Denman Tire Company and that the engineering specifications or blueprings are owned by Dunlap Kyle of Batesville, Mississippi. Please send me copies of any and all information you have concerning this tire or any information applicable to this tire concerning standards, specifications, strength and endurance tests. I am particularly concerned with the sidewall and bead construction specifications and standards. Thank you. William H. Tucker |
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ID: nash2.ajdOpenMr. Rod Nash Dear Mr. Nash: This is in reply to your letter dated September 17, 2003 on behalf of Capacity of Texas, which is a subsidiary of Collins Industries, Inc. (Collins), with respect to the early warning reporting regulation, 49 CFR Part 579. This office received your letter on September 26, 2003. In your letter, you reference and attach two communications from the National Highway Traffic Safety Administration (NHTSA): one was my letter of August 20, 2003 and the other was an e-mail from Bob Squire of NHTSAs Office of Defects Investigation. You stated that "Capacity of Texas is willing to report information on the one hundred or so spotter trucks they build a year that are certified for on highway use."You further stated that if the volume of trucks is so small that only reporting deaths is the appropriate procedure, then you are prepared to follow that directive. The reference to trucks in your letter is not clear. Collins and its subsidiaries must report according to the aggregate production of each vehicle category. Therefore, we expect Collins or Capacity of Texas to report for each vehicle category for which the aggregate production by Collins and all its subsidiaries and affiliates is 500 or more. Thus, for example, if the spotter trucks are medium-heavy vehicles, and Collins and/or its subsidiaries also manufacture medium-heavy vehicles, the production volumes of all these companies vehicles must be aggregated to determine whether the companies must report under 49 CFR 579.22 or 579.27. Please note that the Office of Defects Investigation has amended the manufacturer identification application to cover situations in which a manufacturer is reporting early warning information on behalf of subsidiaries or affiliated companies. Therefore, when applying for a manufacturers identification number for early warning reporting, the reporting entity has to identify each parent, subsidiary, or affiliate for which it will be providing information. If you have any questions regarding this letter, you may phone Andrew DiMarsico of my staff at (202) 366-5263.Any questions on the manufacturer identification application should be presented to Jon White of NHTSAs Office of Defects Investigation, who may be reached at (202) 366-5226. Sincerely, Jacqueline Glassman ref:579 |
2003 |
ID: nht88-3.39OpenTYPE: INTERPRETATION-NHTSA DATE: 09/10/88 FROM: LARRY P. EGLEY TO: KATHLEEN DEMETER -- ASST. CHIEF COUNSEL NHTSA TITLE: NONE ATTACHMT: ATTACHED TO LETTER DATED 08/09/89 FROM STEPHEN P. WOOD -- NHTSA TO LARRY P. EGLEY; REDBOOK A33[2]; STANDARD 108; LETTER DATED 01/17/89 FROM LARRY P. EGLEY TO KATHLEEN DEMETER -- NHTSA; OCC 3028; LETTER DATED 05/23/89 FROM LARRY P. EGLEY TO KATH LEEN DEMETER -- NHTSA; REPORT DATED 09/10/88 FROM LARRY P. EGLEY, REQUEST FOR EVALUATION / INTERPRETATION OF PROPOSED INVENTION SUDDEN STOP FLASHER [SSF]; REPORT DATED 09/07/88 FROM LARRY P. EGLEY, AN APPEAL FOR VARIANT INTERPRETATION OF NHTSA STANDARDS AS THEY RELATE TO BRAKE LIGHTS AND THE SUDDEN STOP FLASHER [SSF]; LETTER DATED 07/13/88 FROM KATHLEEN DEMETER -- NHTSA TO LARRY P. EGLEY; LETTER DATED 06/23/88 FROM LARRY P. EGLEY TO RALPH HITCHCOCK -- NHTSA; OCC 2256; LETTER DATED 06/20/88 FROM LEWIS S. BUCHANAN -- EPA TO LARRY P. EGLEY; OCC 2199; LETTER DATED 06/09/88 FROM LARRY P. EGLEY TO LEWIS BUCHANAN TEXT: Dear Ms DeMeter: I recently sent two letters to NHTSA, the first dated June 9, 1988 and the second dated June 23, 1988, in which I described my invention, the "Sudden Stop Flasher (SSF)." I requested an evaluation or interpretation to determine if my device would meet the standards established by NHTSA, AND I also requested "reasonable confidentially." You responded in a letter dated July 13, 1988 that NHTSA "requires that all of its interpretations be made publically available." Since the SSF is now registered in the U.S. Patent Office, I have decided to allow NHTSA to conduct an evaluation and publicize the results as required. However, please ignore the two letters referenced above for purposes of the evaluation and replace them with Enclosures (1) and (2), attached. The Enclosures attached will be much easier for the evaluators to follow than the two misdirected letters, which are somewhat disjointed and contain extraneous details. Thank you for your attention. Enclosures: (1) Request for Evaluation/Interpretation of Proposed Invention: "Sudden Stop Flasher (SSF)" (2) An Appeal for Variant Interpretation of NHTSA STANDARDS as they Relate to Brake Lights and the Sudden Stop Flasher (SSF) |
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.