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: aiam4280OpenMr. James R. Mitzenberg, Project Engineer, The Flxible Corporation, 970 Pittsburgh Drive, Delaware, Ohio 43015; Mr. James R. Mitzenberg Project Engineer The Flxible Corporation 970 Pittsburgh Drive Delaware Ohio 43015; Dear Mr. Mitzenberg: This is in reply to your letter of January 22, 1987, asking furthe questions of permissible lamp operations.; With reference to the deceleration warning system discussed previousl in our correspondence, you have asked whether there would be a noncompliance with Standard No. 108 if the triple steady burning amber lamps are operated simultaneously wit the steady burning rear stop lamps, or with the flashing turn signal lamp (either red or amber). In neither instance do we believe that an impairment of required lighting equipment would result, within the prohibition of paragraph S4.1.3.; I hope that this answers your questions. Sincerely, Erika Z. Jones, Chief Counsel |
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ID: aiam1639OpenMr. Sol M. Edidin, Executive Director, Car and Truck Renting and Leasing Association, 1725 K Street, N.W., Washington, DC 20006; Mr. Sol M. Edidin Executive Director Car and Truck Renting and Leasing Association 1725 K Street N.W. Washington DC 20006; Dear Sol: This responds to your July 25, 1974, letter and our subsequen discussions which raise the question whether the construction of a truck using the power train (rear axle, suspension, drive line, and engine) of a damaged 1972 truck and all or part of a new glider kit constitutes the manufacture of a new motor vehicle, subject to Federal motor vehicle safety standards, including Standard No. 121 after March 1, 1975.; Re-use of components from an existing vehicle in the construction o another vehicle may or may not result in the manufacture of a new vehicle. The NHTSA has established that the addition of new components (such as a truck body) to the chassis of a used vehicle does not constitute the manufacture of a new vehicle. Conversely, the addition of used components to a new chassis which has never been certified in a vehicle constitutes the manufacture of a new vehicle, subject to the safety standards in effect for that vehicle class on the date of manufacture. This criterion has been relied on in the area of chassis-cab multistage manufacture.; Typically a 'glider kit' is a truck chassis on which a cab and fron axle system are mounted, which is purchased to permit the re-utilization of a power train from another vehicle. Since a glider kit typically incorporates a new chassis (as well as a new cab and front suspension), the NHTSA finds that the use of such a glider kit in the construction of a motor vehicle constitutes the manufacture of a new motor vehicle. To conclude otherwise would mean that a vehicle composed entirely of brand new components except the rear axle and perhaps the engine and transmission, would qualify as a used vehicle.; In answer to your question on the use of a portion of the kit: if th kit's chassis portion is used, we would consider the resultant vehicle to be a new motor vehicle. Conversely, use of only the cab portion would not be the manufacture of a new motor vehicle.; A new motor vehicle must conform to all applicable Federal moto vehicle safety standards. If it is *not* manufactured in two or more stages, the applicable standards are those in effect for the vehicle type as of the date of completion of the vehicle (15 U.S.C. S 1397(a)(1)) (49 CFR 567.4). If the vehicle has been manufactured in two or more stages in accordance with Part 568 (*Vehicles manufactured in two or more stages*, 49 CFR Part 568), it may be certified as of any date between the date of manufacture of the 'incomplete vehicle' and the date of manufacture of the completed vehicle. For example, a truck- tractor constructed of a 1972 power train and a glider kit on some date prior to March 1, 1975, may be certified as of the date that it reaches the 'incomplete' stage although its completion (such as by fifth-wheel installation) occurs after March 1, 1975.; The manufacturer responsible for certification under Part 567 (49 CF Part 567) will in many cases be the person who combines the used components with the glider kit. However, if he has manufactured only an 'incomplete vehicle' as that term is defined in Part 568, he would provide documentation with the vehicle required under S 568.4.; Although a glider kit manufacturer may use several serial number (e.g., body, engine) the NHTSA only requires one vehicle identification number to appear on the certification plate (S 567(4)(g)(6)). The manufacturer may use the serial number on the glider kit or may create his own vehicle identification number. It is my understanding that the States have established various practices for the registration of a vehicle which is partially constructed from a formerly registered vehicle. These practices vary greatly and you should check with the individual States regarding them.; Yours truly, Richard B. Dyson, Acting Chief Counsel |
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ID: aiam2503OpenMr. Tokia Iinuma, Nissan Motor Co., Ltd., P.O. Box 1606, Englewood Cliffs, N.J. 07632; Mr. Tokia Iinuma Nissan Motor Co. Ltd. P.O. Box 1606 Englewood Cliffs N.J. 07632; Dear Mr. Iinuma: This responds to your January 6, 1977, question regarding the effectiv date of the recent amendment to Standard No. 116, *Motor Vehicle Brake Fluids*, That specifies color coding requirements for brake fluids (41 FR 54942, December 16, 1976). You asked whether motor vehicles manufactured after the effective date for the color coding requirements (September 1, 1978) may be equipped with brake fluids manufactured prior to that date that do not conform to the color coding requirements. The answer to your question is yes. Paragraph S5.3 of Standard No. 116 specifies that motor vehicles having hydraulic brake systems shall be equipped with brake fluid that has been manufactured and packaged in conformity with the requirements of the standard. The agency interprets this to mean that vehicles shall be equipped with any brake fluid that conformed to the requirements of Standard No. 116 at the time the brake fluid was manufactured.; Sincerely, Frank Berndt, Acting Chief Counsel |
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ID: 2022-9-15 Letter to CBP on Legality of Odometer Mileage Blocking DevicesOpenSeptember 15, 2022 John Donaldson |
2022 |
ID: aiam1605OpenMr. John J. Relihan, Solomon, Relihan & Blake, Law Offices, Suite A, 1819 West Osborn Road, Phoenix, AZ 85015; Mr. John J. Relihan Solomon Relihan & Blake Law Offices Suite A 1819 West Osborn Road Phoenix AZ 85015; Dear Mr. Relihan: This is in response to your letter of September 9, 1974, inquiring a to the compliance of the AADA-65 odometer disclosure form with the Federal odometer requirements.; Your letter suggests that this agency has 'approved' the Form AADA-6 as complying with the provisions of the odometer regulation. We are, however, unaware of any past correspondence between this office and either the Arizona Automobile Dealers Association or Norwick Printers of Oklahoma concerning the validity of a disclosure statement.; The Form AADA- 65 enclosed in your letter fails to comply with ou regulation in several respects. The statement referring to the mileage indicated on the odometer at the time of the vehicle's transfer must be phrased to indicate that the disclosure document was executed at the time of the vehicle's transfer, not at some later time. In addition, the statement must be written in such a manner that it is clear it is to be completed by the transferor alone. To satisfy these criteria the statement should read; >>>'I, * *, state that the odometer mileage indicated on the vehicl described above, at the time of transfer to * * is as follows:'<<<; The portion of the document provided for disclosure of the odomete mileage and a statement as to its accuracy is also deficient. Instructions are necessary on this part of the form to ensure that it is completed in a consistent manner by all persons. The number of miles indicated on the odometer at the time of the vehicle's transfer need not appear a second time if the form includes the statement recommended above. If the seller wishes, he may indicate on the form that the actual mileage is over 100,000 miles. In addition, the statement concerning the accuracy of the vehicle's reflected mileage must be more complete than the one included in form 'B'. Completion of the disclosure document in accordance with these directions may be accomplished as follows:>>>; '(Complete line 1, and where applicable, complete line 2 and check lin 3:); 1. * * miles 2. * * total cumulative miles (if over 100,000). 3. [ ] I further state that the actual mileage differs from th odometer reading for reasons other than odometer calibration error and that the actual mileage is unknown.'<<<; You expressed some confusion concerning the circumstances under which statement should be made that the actual odometer mileage is unknown. The intended purpose of the disclosure statement is to inform the purchaser of a vehicle as to the accuracy of the mileage registered on the odometer. In order to accomplish this purpose it has been determined that where the seller of a vehicle has good reason to believe that the mileage registered on the odometer differs from the vehicle's true mileage he must so inform the buyer in positive terms. In the situation where the transferor is uncertain whether the mileage is accurate, he must determine whether there is a credible basis for an assumption that the mileage is either correct or incorrect. If he has good reason to believe that the mileage is inaccurate, even though he is not positive, he should check the statement saying that the mileage indicated on the odometer is incorrect. A statement from a prior transferor that the odometer mileage is incorrect constitutes sufficient basis for a like statement upon subsequent transfer of the vehicle.; Yours truly, Richard B. Dyson, Acting Chief Counsel |
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ID: aiam5299OpenMr. David Shapiro RV Designer Collection Woodbridge, Inc. Glenview, IL 60025; Mr. David Shapiro RV Designer Collection Woodbridge Inc. Glenview IL 60025; "Dear Mr. Shapiro: This responds to your inquiry about th applicability of Standard No. 302, Flammability of Interior Materials to aftermarket products. You state that you are planning to market fabric window coverings such as drapes and fabric bedding such as bedspreads for use in recreational vehicles. In response to your request for confirmation that Standard No. 302 does not apply to aftermarket products, I am pleased to have this opportunity to explain our regulations to you. By way of background information, NHTSA is authorized to issue Federal Motor Vehicle Safety Standards that set performance requirements for new motor vehicles and items of motor vehicle equipment. NHTSA does not, however, approve or certify any vehicles or items of equipment. Instead, the Safety Act establishes a 'self-certification' process under which each manufacturer is responsible for certifying that its products meet all applicable safety standards. The agency periodically tests new vehicles and items of equipment for compliance with the standards. In response to your question, there are currently no Federal motor vehicle safety standards (FMVSS's) that directly apply to the products you wish to manufacture. Under the authority of the Safety Act, NHTSA has issued Standard No. 302, which specifies requirements for the flammability resistance of materials in the occupant compartment of new vehicles. However, Standard No. 302 would not apply to your products because that standard applies to new motor vehicles and not to aftermarket items of motor vehicle equipment. I note, however, that there are other Federal requirements that indirectly affect the manufacture and sale of your products. Under the Safety Act, your products are considered to be items of motor vehicle equipment. As a manufacturer of motor vehicle equipment, you are subject to the requirements in 151-159 of the Safety Act concerning the recall and remedy of products with safety related defects. I have enclosed an information sheet that briefly describes those responsibilities. In the event that you or NHTSA determines that your products contain a safety-related defect, you would be responsible for notifying purchasers of the defective equipment and remedying the problem free of charge. I note that even though Standard No. 302 would not apply to your product, the product's flammability characteristics could be relevant to whether it contained a safety related defect. Manufacturers, distributors, dealers, and motor vehicle repair businesses are subject to 108(a)(2)(A) of the Safety Act, which states: 'No manufacturer, distributor, dealer, or motor vehicle repair business shall knowingly render inoperative ... any device or element of design installed on or in a motor vehicle or item of motor vehicle equipment in compliance with an applicable Federal motor vehicle safety standard ....' This section would prohibit any manufacturer, distributor, dealer, or repair business from installing your product in used vehicles if the effect of such installation was to render inoperative the compliance of the vehicle with any safety standard, including Standard No. 302. The 'render inoperative' prohibition of 108(a)(2)(A) does not apply to the actions of vehicle owners in adding to or otherwise modifying their vehicles or items of motor vehicle equipment. Thus, if your products were placed in vehicles by the vehicle owners, your products would not need to meet any FMVSSs. Nevertheless, in the interest of safety, we suggest you consider conforming your product to a flammability resistance standard equivalent to Standard No. 302. I hope this information is helpful. If you have any further questions about NHTSA's safety standards, please feel free to contact Marvin Shaw of my staff at this address or by telephone at (202) 366-2992. Sincerely, John Womack Acting Chief Counsel Enclosure"; |
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ID: aiam5203OpenMr. Bob Davis Quality Control Manager Horton Emergency Vehicles 500 Industrial Mile Road Columbus, OH 43228; Mr. Bob Davis Quality Control Manager Horton Emergency Vehicles 500 Industrial Mile Road Columbus OH 43228; Dear Mr. Davis: This is in response to your letter of April 13, 1993 requesting an interpretation of Federal Motor Vehicle Safety Standard (FMVSS) No. 206 as it affects the rear doors of ambulances that your company manufactures. I apologize for the delay in responding. You state that your ambulances have two rear doors, and that each has locking mechanisms that can be operated both from the outside and inside of the doors. Your specific question is whether you can eliminate the inside locking mechanism on one of the rear doors without violating Standard No. 206. The language in S4.1.3 of Standard No. 206 that you noted in your letter (i.e., 'Each door shall be equipped with a locking mechanism with an operating means in the interior of the vehicle.') refers to side doors, but not to rear doors. Thus, your company's ambulances need not be equipped with locking mechanisms on each rear door. I hope this information has been helpful. If you have any further questions feel free to contact David Elias of my office at the above address or by phone at (202) 366-2992. Sincerely, John Womack Acting Chief Counsel; |
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ID: aiam5204OpenMr. Bob Davis Quality Control Manager Horton Emergency Vehicles 500 Industrial Mile Road Columbus, OH 43228; Mr. Bob Davis Quality Control Manager Horton Emergency Vehicles 500 Industrial Mile Road Columbus OH 43228; Dear Mr. Davis: This is in response to your letter of April 13, 1993 requesting an interpretation of Federal Motor Vehicle Safety Standard (FMVSS) No. 206 as it affects the rear doors of ambulances that your company manufactures. I apologize for the delay in responding. You state that your ambulances have two rear doors, and that each has locking mechanisms that can be operated both from the outside and inside of the doors. Your specific question is whether you can eliminate the inside locking mechanism on one of the rear doors without violating Standard No. 206. The language in S4.1.3 of Standard No. 206 that you noted in your letter (i.e., 'Each door shall be equipped with a locking mechanism with an operating means in the interior of the vehicle.') refers to side doors, but not to rear doors. Thus, your company's ambulances need not be equipped with locking mechanisms on each rear door. I hope this information has been helpful. If you have any further questions feel free to contact David Elias of my office at the above address or by phone at (202) 366-2992. Sincerely, John Womack Acting Chief Counsel; |
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ID: aiam3704OpenMr. H. Nakaya, Manager, Mazda (North America) Inc., 23777 Greenfield Road - Suite 462, Southfield, MI 48075; Mr. H. Nakaya Manager Mazda (North America) Inc. 23777 Greenfield Road - Suite 462 Southfield MI 48075; Dear Mr. Nakaya: This is in reply to your letter of May 24, 1983, asking whether th headlamp bezel is considered a 'styling ornament or other feature' for purposes of paragraph 5.2 of SAE J580 *Sealed Beam Headlamp Assembly*, Aug 79 incorporated by reference in Standard No. 108.; The referenced SAE paragraph prohibits styling ornaments or othe features in front of the lens when the headlamp is in use. The intent of this paragraph is to guarantee optimum light output from the headlamp by insuring that no part of the vehicle interferes with the light pattern. If a headlamp bezel is so large that it could interfere with the design light patterns of the lamp, we would consider it a 'styling ornament or other feature' within the meaning of paragraph 5.2.; An oversize bezel interfering with light output would also b prohibited by paragraph S4.1.3 of Standard No. 108 which prohibits installation of motor vehicle equipment that impairs the effectiveness of lighting equipment which the standard requires.; I hope that this answers your question. Sincerely, Frank Berndt, Chief Counsel |
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ID: aiam5268OpenMr. Donald W. Vierimaa Vice President-Engineering Truck Trailer Manufacturers Association 1020 Princess Street Alexandria, VA 22314; Mr. Donald W. Vierimaa Vice President-Engineering Truck Trailer Manufacturers Association 1020 Princess Street Alexandria VA 22314; Dear Mr. Vierimaa: This responds to your letter of October 19, 1993 with respect to the trailer conspicuity requirements of Standard No. 108. You report that ' o ften a new tank trailer will be sold to a customer who will contract with another party to have a lining installed in the tank.' Because of the high heat used in the installation of the lining, retroreflective sheeting cannot be applied before the lining is installed. We believe that the trailer manufacturer is a more appropriate person for ensuring that its product meets the conspicuity requirements of Standard No. 108 than the installer of the lining, or the owner of the trailer. We would like to suggest alternative methods of compliance, other than a direct application of retroreflective tape to the trailer sides, as a resolution of this problem. Standard No. 108 permits the use of reflex reflectors as an alternative to retroreflective sheeting. If the trailer manufacturer prefers retroreflective sheeting, the sheeting may be applied at a lower level if deemed 'practicable', or it may be applied to horizontal strips of aluminum that can be fastened to the sides of tank trailers and removed during the installation of the lining. You also state that 'non-tank trailers may be sold without conspicuity treatment when the owner wishes to contract the application of special paint and logo schemes.' Sale of a trailer under these circumstances, without its compliance with the conspicuity requirements of Standard No. 108, would be an apparent violation of the National Traffic and Motor Vehicle Safety Act. Sincerely, John Womack 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.