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: nht93-9.13OpenDATE: December 14, 1993 FROM: Michael S. Marczynski -- Sales Representative, Anita's Auto World TO: Office Of The Chief Council -- NHTSA TITLE: NONE ATTACHMT: Attached To Letter Dated 6/3/94 From John Womack To Michael S. Marczynski (A42; Std. 108; 205; 208; 216; 302; VSA 109(A)(2)(A)) TEXT: Dear Chief Council, This letter is in regards to a telephone conversation on 12-14-93 with a Mr. Entwhistle of your Washington office. The topic of the conversation was about obtaining a formal written notice from you concerning the legal installation of roll pans, and convertible tops on light-duty pick-up trucks. Some of our customers have expressed concern over the legal aspects of having these items installed in their vehicles. If at all possible, could you please address this issue in letter form for us. We are a professional body/paint shop located in Lansing, Michigan, and would like to perform this after-market installation as a service to our customers. I feel a written letter would carry more validity for us. Thank-you for your time. If you have any questions please feel free to contact me at (517) 487-2220. Sincerely, |
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ID: nht72-1.22OpenDATE: 09/27/72 FROM: AUTHOR UNAVAILABLE; R. L. Carter; NHTSA TO: Goodyear Tire & Rubber Company TITLE: FMVSS INTERPRETATION TEXT: This is in reply to your letter of August 24, 1972, requesting an opinion as to the applicability of Motor Vehicle Safety Standard No. 109 (49 CFA 471.109) and proposed Standard No. 110 (37 F.R. 13491, July 8, 1972) to tires inflated with "Permafoam" cellular foam rubber. Although these tires contain other material in addition to air, we have decided that they should be considered "pneumatic tires" for the purpose of the application of Standard No. 109. The reasons for this decision are the fact that their Foam filling contains a substantial proportion of air under pressure, and their general similarity to conventional tires in regard to appearance, use, and load-deflection characteristics. The NHTSA has also concluded, however, that these tires have desirable performance capabilities and should be available to the public, subject to conditions to assure their safe use, for the special purposes for which they are designed. Accordingly we have decided to initiate rulemaking to establish special requirements for these and similar tires. We plan to issue the appropriate notices in the near future. |
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ID: nht72-5.21OpenDATE: 03/24/72 FROM: AUTHOR UNAVAILABLE; Richard B. Dyson; NHTSA TO: Truck Equipment & Body Distributors Association TITLE: FMVSR INTERPRETATION TEXT: This is in reply to your letter of March 6, 1972, concerning the certification of pickup trucks that are modified while still in the hands of a dealer. You describe a situation in which the dealer removes the pickup body and sends the vehicle to a final-stage manufacturer for fitting with a service body. We would consider modifications of the type you describe to be manufacturing under the National Traffic and Motor Vehicle Safety Act, and the Certification regulations (49 CFR Part 567). Because a completed vehicle is involved regulations governing Vehicles Manufactured in Two or More Stages (Part 568) do not apply. One who remanufactures a completed vehicle assumes the responsibility of any manufacturer of completed vehicles. The extent to which he may safely rely on the original GVWR, GAWR, and statement of conformity depends on what he has done to alter the vehicle. He is required to certify the vehicle by affixing his own label, and must take into account the effects of any modifications he makes. |
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ID: 86-5.43OpenTYPE: INTERPRETATION-NHTSA DATE: 11/12/86 FROM: ERIKA Z. JONES -- NHTSA CHIEF COUNSEL TO: JEROME J. ABT -- TRIM-LINE OF WEST WISCONSIN TITLE: NONE ATTACHMT: LETTER DATED 09/25/85 FROM JEROME J. ABT TO TAYLOR VINSON -- NHTSA TEXT: Dear Mr. Abt: This is in reply to your letter of September 25, 1985, to Mr. Vinson of this office. As a seller of aftermarket "flush mount luggage racks" you are concerned about potential liability should a rear-end collision occur when luggage is carried and blocks the center high-mounted stop lamp (mandatory on all passenger cars manufactured on or after September 1, 1985). Such an occurrence would not be a violation of the National Traffic and Motor Vehicle Safety Act under which the high-mounted stop lamp standard was issued, as compliance would be judged only with the rack in place but not in use. Your question then cannot be answered under Federal law, but only under the laws of the individual State in which an accident occurs. I suggest that you consult your local counsel for advice. Sincerely, |
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ID: nht90-4.85OpenTYPE: Interpretation-NHTSA DATE: December 14, 1990 FROM: William J. Bethurum -- Patent Attorney TO: Legal Counsel, U.S. National Highway Safety Commission TITLE: None ATTACHMT: Attached to letter dated 2-26-91 from Paul Jackson Rice to William J. Bethurum (A37; Std. 108) TEXT: My client, Mr. E. D. Farnsworth of Sweet, Idaho has asked me to write to you concerning the matter of when and how side lights adjacent to the main head lights came to be first used with head lights on automobiles. Mr. Farnsworth has made several new an d useful improvements in the field of automobile head lights and associated side lights, and he has recently filed a United States Patent application for one of his inventions in this field. However, Mr. Farnsworth submitted one of his earlier ideas in this field to an invention promotion firm on the East Coast under an agreement of confidentiality, and Mr. Farnsworth feels that perhaps this agreement may have been breached in view of the ma ny new side light designs that he has recently seen in national magazines. In the event we decide to approach prospective licensees about the licensing of our pending patent application, will you please advise us of what assistance your office can give us in the area of transportation regulations which may govern the applicatio n of new head lamp designs for automobiles or other motor driven vehicles. Any information you may have in this regard will be most appreciated. |
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ID: nht71-4.21OpenDATE: 10/15/71 FROM: AUTHOR UNAVAILABLE; Lawrence R. Schneider; NHTSA TO: Dow Chemical Europe, S.A. TITLE: FMVSS INTERPRETATION TEXT: This is in reply to your letter of September 24 to Francis Amstrong regarding the effective date of the new Federal motor vehicle brake fluid standard, No. 116. The effective date of March 1, 1972, means that any vehicle manufactured on or after that date for sale in the United States must be equipped with brake fluid meeting Motor Vehicle Safety Standard No. 116. |
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ID: nht73-2.6OpenDATE: 05/18/73 FROM: AUTHOR UNAVAILABLE; Richard B. Dyson; NHTSA TO: Femco Inc. TITLE: FMVSR INTERPRETATION TEXT: This is in reply to your letter of April 16, 1973, inquiring whether any Federal laws apply to your building and installation of a man-lift (pictures of which you enclose) in a completed pick-up truck. You state you understand that if the man-lift is installed on a completed vehicle, you are not considered the final-stage manufacturer. Based on the information you have provided us, we believe your interpretation to be correct. It does not appear that you have altered the pick-up truck in a way that would make your company responsible for conformity with Federal safety standards or regulations. The NHTSA has proposed certain requirements for vehicle alterers (copy enclosed). These requirements would very likely apply to you, when effective, if the addition of the man-lift occurs before the purchase of the pick-up truck for a purpose other than resale. |
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ID: nht68-3.29OpenDATE: 04/24/68 FROM: AUTHOR UNAVAILABLE; Joseph R. O'Gorman; NHTSA TO: Finderne Engine Co., No. 1, Inc. TITLE: FMVSS INTERPRETATION TEXT: Thank you for your letter of April 8, 1968, to the National Highway Safety Bureau, concerning the applicability of lighting requirements to fire trucks. We agree that the front identification lamps might be slightly obscured while the stationary and rotating red and amber lights are flashing. However, when these lights are not flashing, the identification lights would clearly identify a vehicle that is more than 80 inches in overall width. Therefore, identification lights will be required on your fire truck. The same reasoning can be applied to clearance lights and compliance is also required. The enclosed literature may be of additional assistance to you in response to your inquiry. We trust this information will be of assistance to you in your desire to comply with existing safety standards. |
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ID: nht69-1.2OpenDATE: 08/22/69 FROM: AUTHOR UNAVAILABLE; L. R. Schneider; NHTSA TO: S. Hoffman, Esq. TITLE: FMVSS INTERPRETATION TEXT: This in further response to your letter of July 14 enclosing an engineering drawing of a hub cap "incorporating a decorative device designed to create an impression of spinning at the center of the wheel during operation of the vehicle", and requesting an interpretation of Federal Motor Vehicle Safety Standard No. 211 with respect thereto. Standard No. 211 specifies the requirement that hub caps, wheel nuts, and wheel discs shall not incorporate winged projections. That in the sole requirement of this Standard. The drawing submitted by you depicta a hub cap which, in our judgment, incorporates a winged projection. The Standard does not regulate vehicle width, and thus your observation that "it would not broaden or extend the front (or top or rear) profile of automobiles . . ." is not a factor to be considered. I enclose the engineering drawing you furnished us. |
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ID: nht74-4.21OpenDATE: 08/14/74 FROM: AUTHOR UNAVAILABLE; Richard B. Dyson; NHTSA TO: Linch-Jones Incorporated TITLE: FMVSR INTERPRETATION TEXT: This is in response to your August 9, 1974, telephone request for a clarification of a transferor's duties under the disclosure requirements of the Federal odometer law. The odometer requirements of the Motor Vehicle Information and Cost Savings Act specify that the transferor of a vehicle provide written disclosure to the transferee of the mileage registered on the odometer at the time of the transaction. If the transferor knows that the odometer reading is incorrect for reasons other than calibration error, a statement to that effect must also be executed at the time ownership of the vehicle is transferred. In the situation where the accuracy of the odometer is in question, the transferror is required to state that the mileage indicated on the odometer is incorrect in accordance with the form specified in @ 580 of 49 CFR Part 580, Odometer Disclosure Requirements, if there is credible evidence indicating the inaccuracy. If the transferror has no firm basis for a conclusion that the odometer reading is incorrect but feels that it may be wrong, he does not violate the Act by indicating that the true mileage may differ from that shown. In so doing, he provides more information than required, and is not guilty of any violation. A statement that the mileage may differ from that indicated on the odometer would only be a violation where positive evidence exists suggesting that the odometer reading is incorrect. In such a situation the transferor must inform the buyer of the inaccuracy in the manner prescribed in the odometer disclosure requirements. If you are in need of any further information, please let us know. |
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.