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: aiam4493OpenMr. Wayne Apple 14738 Bronson Avenue San Jose, CA 95124; Mr. Wayne Apple 14738 Bronson Avenue San Jose CA 95124; Dear Mr. Apple: This is in reply to your letter of December 29, 1987 in which you ask whether a U-Turn Indicator 'is reasonable, within federal regulations or specifications, and if the Department of Transportation has interest in the concept and/or product.' Federal Motor Vehicle Safety Standard No. 108, Lamps, Reflective Devices, and Associated Equipment contains specifications for original and replacement lighting equipment. None of these specifications is for a U-turn indicator. However, a U-turn indicator is acceptable as original vehicle equipment provided it does not impair the effectiveness of the lighting equipment that the standard requires, such as turn signal lamps, headlamps, taillamps, and stop lamps. Your proposed specifications recognize the importance of differentiation between the left turn signal and the U-turn indicator, and we encourage you to minimize the possibility of impairment. Standard No. 108 does not cover a U-turn indicator as an aftermarket device, but it is subject to the general restriction that its installation must not render inoperative, in whole or in part, any lamp, reflective device, or associated equipment that was installed pursuant to Standard No. 108. (15 U.S.C. 1397(a)(2)(A)) The legality of use of an aftermarket device of this nature would be determinable under the laws of the State in which a vehicle equipped with it is registered or operated. The American Association of Motor Vehicle Administrators, 120l Connecticut Ave. N.W., Washington, D.C. 20036, may be able to advise you further on State laws. Accident data available to the agency does not permit us to identify specific crashes in which a vehicle is making a U-turn. However, an analysis of data from one of our files that contains information on almost 3 million crashes indicates that the general type of crash for which U-turn crashes are a subset (left-turning crashes) constitutes less than 6% of the total crash experience. Thus, we believe that the number of U-turn crashes is substantially less than the 6% represented by the broader category of crashes involving left-turning vehicles. We do not know the basis for your statement that your U-turn indicator 'will probably reduce accidents involving U-turns by over thirty percent'. However, the agency is interested in exploring concepts that could enhance vehicle safety. I am providing our Office of Research and Development with a copy of your letter for such further comment as may be warranted. We appreciate your interest in safety. Sincerely, Erika Z. Jones Chief Counsel CC: Michael Finkelstein; |
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ID: aiam3356OpenMr. C. Rodney Kuhns, 132 Frement Place, Los Angeles, CA 90005; Mr. C. Rodney Kuhns 132 Frement Place Los Angeles CA 90005; Dear Mr. Kuhns: This responds to your letter of August 10, 1980, in which you as whether your proposed urban transport vehicle would be classified as an automobile or a motorcycle.; The agency's definition of 'motorcycle' is given in 49 CFR S 571.3 which reads in part:; >>>'Motorcycle' means a motor vehicle with motive power having a sea or saddle for the use of the rider and designed to travel on not more than three wheels in contact with the ground.<<<; Based on our understanding of your drawings, your proposed vehicle ha more than three wheels. If our understanding is correct, your vehicle would be classified as a passenger car rather than as a motorcycle.; The requirements for passenger cars are more stringent than fo motorcycles. We have enclosed a pamphlet prepared by the agency which gives a brief summary of the requirements and applicability of each of the Federal motor vehicle safety standards (issued as of August 1978). However, because of the volume of these standards, we do not provide copies directly. We have enclosed an information sheet which explains how you can obtain up-to-date copies of our standards and other regulations.; This agency does not license any vehicles for street or highway use Licensing is handled by the States. We specify performance requirements, and any motor vehicle must be certified by its manufacturer as being in compliance with all applicable safety standards as of the date of its manufacture. If the vehicle complies with these requirements, we specify no further steps which must be taken.; The agency will provide confidential treatment for your letter an accompanying drawings.; Sincerely, Frank Berndt, Chief Counsel |
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ID: aiam1374OpenHonorable John W. Davis, House of Representatives, Washington, DC 20515; Honorable John W. Davis House of Representatives Washington DC 20515; Dear Mr. Davis: This is in reply to your letter of December 17, 1973, on behalf of Ms Judith Davis, who has suggested the incorporation of the Federal odometer form into the bill of sale as a means of reducing paperwork in motor vehicle transactions.; Although the Federal odometer disclosure regulation requires the selle to give the buyer several items of information that we consider essential to adequate disclosure, the regulation does not require the use of a separate form. If Ms. Davis is able to include the required information in the bill of sale used by the Rome Auto Auction, she may do so. Information items that are common to the bill of sale and the disclosure statement, such as the model and make of the vehicle, would not have to be stated twice.; Yours truly, Richard B. Dyson, Assistant Chief Counsel |
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ID: aiam4176OpenMr. Larry H. McEntire, Administrator, School Transportation, Florida Department of Education, Tallahassee, FL 32301; Mr. Larry H. McEntire Administrator School Transportation Florida Department of Education Tallahassee FL 32301; Dear Mr. McEntire: I regret the delay in responding to your letter to this office askin whether certain 'mini-vans' designed to carry a maximum of eight persons are classified by NHTSA as 'passenger cars' or 'multipurpose passenger vehicles' (MPV's), for purposes of complying with the Federal motor vehicle safety standards.; I would like to begin by clarifying that the classification of particular vehicle is determined in the first instance by its manufacturer, and not by NHTSA. Under our certification requirements (49 CFR Part 567), manufacturers are required to specify the type of their vehicles in accordance with the definitions set forth in Part 571.3 of our regulations and must certify that their motor vehicles comply with all the motor vehicle safety standards applicable to that type. We define an MPV in Part 571.3 as 'a motor vehicle ... designed to carry 10 persons or less which is constructed either on a truck chassis or with special features for occasional off-road operation.'; Information we have received regarding manufacturer certificatio discloses that manufacturers classify *cargo- carrying* models of the Ford Aerostar, and G.M. Astro and Safari as 'trucks.' A 'truck' is defined in Part 571.3 as 'a motor vehicle...except a trailer, designed primarily for the transportation of property or special purpose equipment.' We understand that *passenger* models of mini-vans designed to carry up to eight passengers utilize the same type of chassis used in truck models. It is likely, therefore, that the passenger model mini-vans you asked about would be classified as MPV's instead of passenger cars. This is verified by the 'MPV' classification given by manufacturers to the Chrysler mini-van and Toyota Van.; On a related matter, you asked for our comments on your Department' recommendation to your school boards that they not condone parents' use of conventional vans (i.e., vans not meeting Federal or State school bus safety regulations) to transport school children to school-related events. Mr. Arnold Spencer of Rockledge, Florida, recently wrote to our office concerning the above recommendation and requested us to explain how our school bus regulations apply to persons owning vans. I have enclosed a copy of our April 25, 1986, response to Mr. Spencer which you might find helpful.; I hope this information is helpful. If you have further questions please feel free to contact us.; Sincerely, Erika Z. Jones, Chief Counsel |
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ID: aiam0836OpenMr. Jerome G. Abeles, Director, Product Planning & Purchasing, Sealy, Incorporated, 666 North Lake Shore Drive, Chicago, IL, 60611; Mr. Jerome G. Abeles Director Product Planning & Purchasing Sealy Incorporated 666 North Lake Shore Drive Chicago IL 60611; Dear Mr. Abeles: This is in reply to your letter of August 10, 1972, concerning th application of Motor Vehicle Safety Standard No. 302, 'Flammability of Interior Materials', to mattress assemblies.; Paragraph S4.1 of the Standard lists mattress covers only. This doe not include the complete mattress assembly. Accordingly, you are correct in your assumption that only the mattress covers must meet the burn rate requirement of Paragraph S4.3. You are also correct in your assumption that mattress assemblies which are not designed to absorb energy on contact with occupants in crash situations are not subject to the Standard.; Yours truly, Richard B. Dyson, Assistant Chief Counsel |
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ID: aiam3719OpenMr. Charles Jayne, Tire Manager, J-B Purchasing Corporation, P.O. Box 692, Auburn, NY 13021; Mr. Charles Jayne Tire Manager J-B Purchasing Corporation P.O. Box 692 Auburn NY 13021; Dear Mr. Jayne: This responds to your recent letter asking about the requirements of 4 CFR Part 574, *Tire Identification and Recordkeeping*. You noted that your company currently retreads tires for its own use, and that you soon plan to retread tires for sale to others. You asked if the tires you retread for your own use need to be identified with a tire identification number. The answer is no.; Section 574.5 of the Tire Identification and Recordkeeping regulatio provides, in part, that, 'Each tire retreader, *except tire retreaders who retread tires for their own use*, shall conspicuously label one sidewall of each tire he retreads by permanently molding or branding into or onto the sidewall, ...a tire identification number....' Your question concerns a situation in which a tire retreader retreads some tires for his own use and some tires for sale or lease to others. To answer your question, it is helpful to examine the purpose of the identification requirement.; The purpose of having the tire identification number labeled on th sidewall of retreaded tires is twofold. First, it enables this agency and the user of the retreaded tire to identify the retreader of the tire in the event of some safety problem with the tire. Second, it enables the tire retreader to accurately identify the retreaded tires it may have to recall. In the case of tires offered for sale or use outside your company, it is plain that both these purposes would be served by having the tire identification number on the sidewall. Therefore, Part 574 requires that each such tire have a tire identification number on one sidewall.; However, with respect to tires retreaded for the retreader's own use it is obvious who retreaded the tire, whether or not a tire identification number appears on the sidewall. Hence, the first purpose listed above would not be served by having the tire identification number on the sidewall of these tires. Further, the retreader can inspect all of the retreaded tires it uses to determine if any are subject to its recall, and assure adequate remedy for those which are within the recall, without publicizing the identification numbers of those tires. Thus, the second purpose set forth above also would not be furthered by having the tire identification number on the sidewall of these tires. Please note, however, that any tire not marked with a tire identification number can never legally be sold or otherwise offered for use outside of your company.; Should you have any further questions or need additional informatio about this topic, please contact Steve Kratzke of my staff at (202) 426-2992.; Sincerely, Frank Berndt, Chief Counsel |
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ID: aiam1724OpenNancy Kolodny, Esq., Office of the General Counsel, Ford Motor Company, The American Road, Dearborn, MI 48121; Nancy Kolodny Esq. Office of the General Counsel Ford Motor Company The American Road Dearborn MI 48121; Dear Ms. Kolodny: This is in reply to your letter of June 10, 1975, asking whether Moto Vehicle Safety Standard No. 108 preempts Section 25950 of the California Vehicle Code with respect to Mercury Monarch taillamps.; Section 25950 requires in pertinent part that all lamps visible fro the rear of a vehicle be red, 'whether lighted or unlighted', except that taillamps may be white when unlighted. Standard No. 108 requires passenger car taillamps to be 'red' (Table III), and 'the taillamp indication' to be red (SAE Standard J585, *Tail Lamps*, June 1966, incorporated by reference into Standard No. 108). The taillamps on the Mercury Monarch are covered with amber lenses. Although the lamp meets the color and photometric requirements of Standard No. 108 when lighted, California is of the opinion that use of the amber lens is prohibited by Section 25950.; Section 103(d) of the National Traffic and Motor Vehicle Safety Act o 1966 prohibits a State from establishing or continuing in effect any motor vehicle safety standard applicable to the same aspect of performance of a vehicle or equipment item as a Federal standard which is not identical to it. We interpret Standard No. 108 as requiring only that the color of the taillamp 'indication' be red. The method by which this is accomplished is left to the vehicle manufacturer. The indication could be provided by a combination of a white bulb and a red lens (the conventional taillamp), a red bulb and white lens (permitted by California) or, as in your case, a red bulb and an amber lens. Although the color of the taillamp lens is not directly specified by Standard No. 108, the performance of the lamp as an assembly is covered in detail by the standard, and we consider that the color aspects of taillamps are within the scope of these requirements. If the lamp assembly complies with the Federal standard, then a State may not prohibit its use. We therefore find that in this instance 49 CFR 571.108, Federal Motor Vehicle Safety Standard No. 108, renders void the requirement of Section 25950 of the California Vehicle Code that unlighted taillamps be colored red.; Sincerely, James C. Schultz, Chief Counsel |
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ID: aiam4526OpenMr. Paul Scully Vice President Peterson Manufacturing Co. 4200 East 135th St. Grandview, MO 64030; Mr. Paul Scully Vice President Peterson Manufacturing Co. 4200 East 135th St. Grandview MO 64030; Dear Mr. Scully: This is in reply to your letter of April 22, l988 asking for a clarification of a letter that this Office sent Wesbar Corporation on March 16, 1988, with respect to the term 'effective projected luminous area.' Wesbar had asked whether it could include the 'illuminated (by the turn signal bulb) reflex reflector portion of the turn signal lens' (Wesbar's language) in its calculation of the l2 square inch minimum effective projected luminous area required by S4.1.1.7 of Safety Standard No. 108. We replied that it could, assuming that the light shines through the reflector. You have pointed out that although a small amount of light escapes through a reflex reflector, the reflector is designed to return light from an outside source, rather than to direct light from a source inside the lamp, and that heretofore agency interpretations (e.g. on October 28, 1970, and October 28, 1979) had expressly excluded reflex reflectors from areas included in the calculation of effective projected luminous area. Reflex reflectors are also excluded from the term by SAE J387 Terminology. We appreciate your calling this matter to our attention. Previous interpretations by this Office clearly indicate that a 'reflex reflector' is not to be included in the calculation of effective projected luminous area. We also note that the SAE definition (paragraph 2, SAE J594f, January l977) is incorporated by reference into Standard No. 108, stating that this item of equipment is one that provides an indication of vehicle presence by reflected light (rather than projected light). We are providing a copy of this letter to Wesbar so that it will be apprised of our reevaluation, and our conclusion that the reflex reflector portion of a lens cannot be included in the calculations of the projected luminous lens area. I hope this clarifies the matter for you. Sincerely, Erika Z. Jones Chief Counsel; |
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ID: aiam0565OpenMr. E. R. Sternberg, Director, Engineering Planning - Truck Group, White Motor Corporation, 100 Brieview Plaza, Cleveland, OH 44144; Mr. E. R. Sternberg Director Engineering Planning - Truck Group White Motor Corporation 100 Brieview Plaza Cleveland OH 44144; Dear Mr. Sternberg:#This is in reply to your letter of January 3, 1972 requesting an interpretation of S4.2.2 of Standard No. 101, as it applies to your proposed method of compliance for push-pull controls.#S4.2.2 requires, in pertinent part, that 'Identification shall be provided for each function of any . . . heating and air conditioning system control, and for the extreme positions of any such control that regulates a function over a quantitative range.' Identification such as that shown in your Example (2) would meet Standard No. 101, while the identification provided in Example (3) would not. Legends such as 'Pull on' and 'Push off' might more clearly indicate control positions than your suggested 'Max (out)' and 'Off (in).' The control which operates both the defroster and heater must identify both functions, 'Defrost' as indicated is insufficient. Legends such as 'Pull to defrost' and 'Push for heat' would be acceptable for conformance.#Sincerely, Richard B. Dyson, Assistant Chief Counsel; |
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ID: aiam2558OpenMr. L. Wenderoth, Bandag of Nassau, Inc., 40 Brook Avenue, Deer Park, New York 11729; Mr. L. Wenderoth Bandag of Nassau Inc. 40 Brook Avenue Deer Park New York 11729; Dear M. Wenderoth: This responds to your March 10, 1977, letter asking whether it i permissible for you to use a DOT number assigned to another tire retreader when you perform special retread work in your plant for the other retreader who lacks facilities to do the work himself.; Standard No. 117, *Retreaded Pneumatic Tires*, requires that th retreader apply a DOT symbol and identification number to the tire. The DOT symbol indicates conformance with Federal regulations. The number enables the National Highway Traffic Safety Administration (NHTSA) to identify the retreader that manufactures the tire. To permit one manufacturer to use the identification number of another would impair the NHTSA enforcement actions. Accordingly, you would not be permitted to use any DOT number other than your own on tires you retread.; Sincerely, Frank A. Berndt, Acting Chief Counsel |
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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.