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
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ID: aiam0124OpenMr. John F. Floberg, Vice President, Firestone Tire and Rubber Company, Akron, Ohio 44317; Mr. John F. Floberg Vice President Firestone Tire and Rubber Company Akron Ohio 44317; Dear Mr. Floberg: This will acknowledge your letters of July 12, 1968, October 10, 1968 and October 31, 1968, to the National Highway Safety Bureau requesting the addition of three 50 Series Centilevered Sidewall tire size designations to Federal Motor Vehicle Safety Standard No. 109.; On the basis of the data submitted indicating compliance with th requirements of Federal Motor Vehicle Safety Standards Nos. 109 and 110 and other information submitted in accordance with the procedural guidelines set forth in *Federal Register* Volume 33, No. 195, Page 14964, dated October 5, 1968, the E50C-16, F50C-16 and H50C-17 tire size designations will be listed within a new table to be established in Appendix A of standard No. 109 and the 3 1/2 inch rim size will be listed within Table I od the Appendix to Standard No. 110. These changes will be published in the *Federal Register* in the near future.; The addition of new tire size designations to the tables i accomplished through an abbreviated procedure consisting of the publication in the *Federal Register* of the petitioned tire sizes or tables. If no comments are received, the amendment becomes effective after 30 days from the date of publication. If comments objecting to amendments are received, additional rule making pursuant to part 216 of the Procedural Rules for Motor Vehicle Safety Standards will be considered.; Sincerely, H.M. Jacklin, Jr., Acting Director, Motor Vehicle Safet Performance Service; |
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ID: aiam5326OpenMr. Steve J. Brooks Program Manager IAD West Coast, Inc. 5761 McFadden Avenue Huntington, Beach CA 92649; Mr. Steve J. Brooks Program Manager IAD West Coast Inc. 5761 McFadden Avenue Huntington Beach CA 92649; "Dear Mr. Brooks: This responds to your letter asking about th operation and classification of a commercial vehicle you wish to manufacture. The vehicle will carry fewer than 10 passengers and its GVWR will be 11,500 pounds. You were particularly interested in the type of operator's license that would be required of the driver. Driver licensing requirements for vehicle operators are determined by state law. Since the vehicle's GVWR will be less than 26,000 lbs, and the vehicle will presumably be designed to carry fewer than 15 passengers, the driver will not be required, under the Federal Highway Administration's (FHWA's) Commercial Driver Licensing (CDL) regulations, 49 CFR part 383, to qualify for a commercial driver license. However, some states require that drivers obtain a commercial driver license to drive vehicles that have lower GVWRs. The driver licensing requirements of the state in which the vehicle is registered, will apply. For more information about the CDL requirements, you can contact the FHWA Chief Counsel's office at (202) 366-0834. Vehicle classification is relevant for the regulations and standards of our agency. The National Traffic and Motor Vehicle Safety Act authorizes the National Highway Traffic Safety Administration (NHTSA) to issue Federal motor vehicle safety standards (FMVSSs) for new motor vehicles and motor vehicle equipment. Each FMVSS for motor vehicles applies to one or more particular types of vehicles, e.g., a standard might apply to passenger cars, buses, trucks, and/or trailers. To determine which FMVSSs apply to their vehicles, manufacturers classify their vehicles using the definitions in 49 CFR part 571.3 of NHTSA's regulations. Under part 571.3 (copy enclosed), your vehicle, which you said is built in a bus/truck chassis, appears to be a 'truck' or a 'multipurpose passenger vehicle.' Under part 567, a manufacturer must state the vehicle classification on the vehicle's certification label and certify that its motor vehicle complies with all applicable FMVSSs. NHTSA may take issue with a manufacturer's vehicle classification in an enforcement proceeding if the agency does not agree with the manufacturer's classification. I hope this information is helpful. If you have any further questions, please contact Dorothy Nakama of my staff at this address or at (202) 366-2992. Sincerely, John Womack Acting Chief Counsel Enclosure"; |
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ID: aiam2549OpenMr. Peter Cooper, 1228 Frick Building, Pittsburgh, PA 15219; Mr. Peter Cooper 1228 Frick Building Pittsburgh PA 15219; Dear Mr. Cooper: This responds to your March 1, 1977, question whether your client, retail tire dealer, would be in violation of the regulations of the National Highway Traffic Safety Administration (NHTSA) if he were to sell tires which do not contain an identification number as required by the NHTSA.; Paragraphs S4.3.1 and S4.3.2 of 49 CFR 571.109, Motor Vehicle Safet Standard No. 109, *New Pneumatic Tires*, requires passenger car tires to be labelled in accordance with Part 574. The absence of an identification number means that the tire is not in compliance with the requirements of Standard No. 109. Section 108(a)(1)(A) of the National Traffic and Motor Vehicle Safety Act of 1966 (the Act) (15 U.S.C. 1381 et seq.) provides in part that no person shall sell any item of motor vehicle equipment that is not in conformity with applicable standards. Since your client would be selling nonconforming tires, he would be in violation of our Act and, therefore, subject to the penalties imposed thereunder. Section 109(a) of the Act establishes a penalty of up to $1,000 for each violation of the Act, not to exceed $800,000 for any related series of violations.; Sincerely, Frank A. Berndt, Acting Chief Counsel |
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ID: aiam0574OpenMr. W. M. Self, Marketing Manager, Downs-Clark, P.O. Box 1386, Brownwood, TX 76801; Mr. W. M. Self Marketing Manager Downs-Clark P.O. Box 1386 Brownwood TX 76801; Dear Mr. Self: This is in reply to your letter of December 30, 1971, concernin whether you must comply with the Certification regulations (49 CFR Part 567) in cases where you 're-barrel' or 're-deck' trailers. You describe these processes as installing a new tank (re-barreling) or platform deck (re- decking) on a used trailer under construction furnished by your customer, which includes axles, tires, wheels, springs, hangers, and internal brake assemblies, in serviceable condition.; You are not required to certify these vehicles as they are manufacture on used chassis and are considered by this agency to be used vehicles under section 108(b)(1) of the National Traffic and Motor Vehicle Safety Act (15 U.S.C. S 1397(b)(1)).; We are pleased to be of assistance. Sincerely, Richard B. Dyson, Assistant Chief Counsel |
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ID: aiam4864OpenGary P. Toth, Esq. General Motors Corporation Legal Staff New Center One Building 3031 West Grand Blvd. P.O. Box 33122 Detroit, MI 48232; Gary P. Toth Esq. General Motors Corporation Legal Staff New Center One Building 3031 West Grand Blvd. P.O. Box 33122 Detroit MI 48232; "Dear Mr. Toth: This responds to your request for an interpretation o how the requirements of Standard No. 209, Seat Belt Assemblies (49 CFR 571.209) would affect some dual-spring retractor designs GM is considering. Your letter said that these dual-spring retractors are designed so that a spring with a lower retraction force is or can be engaged when the safety belt is being worn by an occupant. When the safety belt is removed, a spring with a higher retraction force is engaged to effectively stow the belt webbing. Your letter also said that the retractor for the shoulder belt portion of the lap/shoulder belts on which these designs would be used is an emergency locking retractor (ELR). The minimum and maximum retractor force requirements for ELRs are set forth in S4.3(j)(5) and (6) of Standard No. 209. Those sections specify minimum and maximum retractor force requirements when the retractors 'are tested in accordance with the procedures specified in paragraph S5.2(j).' S5.2(j) specifies that, for the purposes of measuring the retractor forces, the webbing shall be fully extended from the retractor and then retracting the webbing to 75 percent extension plus or minus 2 inches. Your letter stated that your dual-spring retractor designs will comply with the minimum retractor force requirements when tested under the conditions specified in S5.2(j). This is because the higher retraction force will always be engaged under those conditions. It appears that, when the higher retraction force is engaged in these dual-spring retractor designs, the retractors will comply with the minimum retractor force requirements. However, when the lower retraction force is engaged, the retractor force is less than the minimum retractor force requirement. Because these dual-spring retractors comply with the retractor force requirements when tested under the conditions specified in S5.2(j) of Standard No. 209, your company is ready to certify these designs as complying with Standard No. 209. You are, however, concerned with the implications of a February 16, 1984 NHTSA interpretation addressed to Mr. Frank Pepe. In that instance, Mr. Pepe stated that the ELR had two tension modes that were activated by the vehicle door. The subject retractor operated in a high tension mode when the vehicle door was open, and in a lower tension mode when the vehicle door was closed. The agency concluded that, because Standard No. 209 does not distinguish between tension modes, the subject retractors would have to comply with all the requirements of the standard, including the minimum and maximum retraction force requirements, in both tension modes. Your letter asked us to reevaluate the conclusions reached in our February 16, 1984 letter to Mr. Pepe. We believe that the facts presented in your letter are significantly different than those that were presented in the Pepe letter, so the conclusions reached in the Pepe letter are not the same we would reach for your company's dual-spring retractors. In the case of the Pepe letter, the starting point for our analysis of whether the retractors would comply with the minimum and maximum retractor force requirements was the language of S4.3(j) in Standard No. 209, which directed us to the test conditions set forth in S5.2(j) of Standard No. 209. However, the test conditions in S5.2(j) complete extension of the webbing, followed by subsequent retraction to 75 percent extension did not adjust the Pepe retractors to either the high or low tension mode. Some additional action beyond the conditions specified in S5.2(j) had to be taken to select either the high or low tension mode. Since the selection of the high or low tension mode was not specified in S5.2(j) or elsewhere in Standard No. 209, NHTSA concluded that the retractor would have to be certified as complying with the retractor force requirements when adjusted to either the high or low tension mode. The GM retractors present a significantly different situation. According to your letter, the conditions set forth in S5.2(j) will adjust the GM retractors in a way so that the higher retraction force will always be engaged. Assuming this to be the case, no adjustments beyond the conditions specified in S5.2(j) would be necessary to select a tension mode for the retractors. In these circumstances, compliance with the minimum retractor force requirements would be determined only under the conditions specified in S5.2(j). Sincerely, Paul Jackson Rice Chief Counsel"; |
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ID: aiam5263OpenMr. Dennis G. Moore President Sierra Products Inc. 1113 Greenville Road Livermore, CA 94550; Mr. Dennis G. Moore President Sierra Products Inc. 1113 Greenville Road Livermore CA 94550; "Dear Mr. Moore: We have received your letter of September 29, 1993 with reference to the location requirements of Standard No. 108 for identification (i.d.) lamps. Table II of the standard in pertinent part specifies the following location for i.d. lamps: 'On the rear - 3 lamps as close as practicable to the top of the vehicle at the same height, as close as practicable to the vertical centerline . . . .' You reference at least two instances in the past 20 years or longer in which 'NHTSA has allowed the slight misalignment of I.D. lights because of `Practical' circumstances,' and have asked for copies of these interpretations. We are unaware of these interpretations. In their absence, you have asked for an interpretation of the phrase 'at the same height' that would permit the mounting height of the center lamp to deviate slightly from the height of the two lamps that flank it, as shown in your letter. You depict two other possible configurations in which the three lamps are mounted at identical heights. In one configuration, the lower edges of the outboard lamps hang below the frame 'making them vulnerable to being damaged or knocked off' in your opinion. In the second configuration, the lamps are raised and protected, but the center lamp is somewhat obscured by the 'typical roller or protective pad.' You deem these configurations undesirable for safety reasons. The question to be answered is whether the configuration you prefer is 'as close as practicable to the top of the vehicle at the same height' (note the absence of a comma between 'vehicle' and 'at'). The determination of practicability is initially that of the manufacturer. Unless it is clearly erroneous, NHTSA will not question it. In the absence of a superstructure, the frame location may be regarded as being 'as close as practicable to the top of the vehicle. . . .' Because 'at the same height' is part of the same phrase, practicability also governs placement of the lamps at the same height. A manufacturer may determine that, for the sake of practicability, i.d. lamps may be mounted at a height sufficient to protect them from breakage (the outboard lamps) and to ensure compliance with photometric requirements (the center lamp). The configuration you depict is sufficiently close to the literal reading of the phrase 'at the same height' that NHTSA would not question the manufacturer's determination of practicability with respect to the mounting height of the center i.d. lamp. Sincerely, John Womack Acting Chief Counsel "; |
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ID: aiam0061OpenMaurice Wexler, Esq., Heiskell, Donelson, Adams, Williams & Wall, Suite 2020 First National Bank Building, Memphis, TN 38103; Maurice Wexler Esq. Heiskell Donelson Adams Williams & Wall Suite 2020 First National Bank Building Memphis TN 38103; Dear Mr. Wexler: Mr. Bridwell has asked that I reply to your letter of April 9, 1968. Enclosed for your information is a copy of the chassis-cab ruling an regulation issued December 29, 1967. Under the terms of the ruling and regulation and the National Traffic and Motor Vehicle Safety Act of 1966, when a truck body manufacturer assembles the truck body to a chassis-cab he is responsible for certification only if the completed vehicle is delivered to a dealer or distributor. The body manufacturer assembling the body to the chassis-cab would, however, be responsible for the vehicle's compliance with the lighting standard if not previously met by the chassis-cab manufacturer. Moreover if the addition of the body affects the chassis-cabs previous compliance with standards the body manufacturer would be responsible for compliance.; With regard to bodies mounted on chassis-cabs manufactured prior t January 1, 1968 compliance and certification is not required. However, the body, if manufactured on or after January 1, 1968, would have to contain glazing that complies with Standard No. 205 because the body is manufactured for use on motor vehicles and as such must meet any applicable equipment standards.; Sincerely, Robert M. O'Mahoney, Assistant Chief Counsel |
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ID: aiam5633OpenMr. James J. Gregorio 6704 Forsythia St. Springfield, VA 22150; Mr. James J. Gregorio 6704 Forsythia St. Springfield VA 22150; "Dear Mr. Gregorio: This responds to your letter of September 23, 1995 requesting 'authorization to modify the car seat in my 1992 Plymouth Acclaim.' Your letter states: Presently, my car is equipped with hand controls which alleviates a condition of chronic tendinitis in my right ankle. Unfortunately, there is practically no room between the hand controls and my knees. My knees constantly bang up against the hand controls. The resulting consequence is that I now have tendinitis in both knees. Modifying the car seat will allow me to push the car seat back far enough to give space to my injured knees. You enclosed a letter from your physician stating that recovery could take several years. In summary, our answer is that you may have your vehicle modified. NHTSA will not institute enforcement proceedings against a repair business that modifies the seat on your vehicle to accommodate your condition. A more detailed answer to your letter is provided below. I would like to begin by noting that repair businesses are permitted to modify vehicles without obtaining permission from NHTSA to do so, but are subject to certain regulatory limits on the type of modifications they may make. In certain limited situations, we have exercised our discretion in enforcing our requirements to provide some allowances to a repair business which cannot conform to our requirements when making modifications to accommodate the special needs of persons with disabilities. Since your situation is among those given special consideration by NHTSA, this letter should provide you with the relief you seek. Our agency is authorized to issue Federal Motor Vehicle Safety Standards (FMVSS) that set performance requirements for new motor vehicles and items of motor vehicle equipment. Manufacturers are required to certify that their products conform to our safety standards before they can be offered for sale. Manufacturers, distributors, dealers, and repair businesses are prohibited from 'knowingly making inoperative' any device or element of design installed on or in a motor vehicle in compliance with an applicable FMVSS. In general, the 'make inoperative' prohibition would require repair businesses which modify motor vehicles to ensure that they do not remove, disconnect, or degrade the performance of safety equipment installed in compliance with an applicable FMVSS. Violations of this prohibition are punishable by civil fines up to $1,000 per violation. Moving a seat, and presumably moving the seat belts for the seat, could affect compliance with four safety standards: Standard No. 207, Seating Systems, Standard No. 208, Occupant Crash Protection, Standard No. 209, Seat Belt Assemblies, and Standard No. 210, Seat Belt Assembly Anchorages. Your letter does not provide any information regarding why the modification to your seat cannot be done in a way that would not violate the make inoperative prohibition. However, in situations such as yours where a vehicle must be modified to accommodate the needs of a particular disability, we have been willing to consider any violations of the 'make inoperative' prohibition a purely technical one justified by public need. As I have already noted above, NHTSA will not institute enforcement proceedings against a repair business that modifies the seat on your vehicle to accommodate your condition. We caution, however, that only necessary modifications should be made to the seat, and the person making the modifications should consider the possible safety consequences of the modifications. For example, in moving a seat, it is critical that the modifier ensure that the seat is solidly anchored in its new location. You should also be aware that an occupant of a seat which has been moved rearward may have less protection in a crash if the seat is too far rearward relative to the anchorages of the safety belts for that seat. Finally, if you sell your vehicle, we encourage you to advise the purchaser of the modifications. I hope this information has been helpful. If you have any other questions or need some additional information in this area, please contact Mary Versailles of my staff at this address or by phone at (202) 366-2992. Sincerely, Samuel J. Dubbin Chief Counsel"; |
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ID: aiam4921OpenCarl Miller, O.E. Sales Manager DICO Tire, Inc. 520 J.D. Yarnell Industrial Parkway Clinton, TN 37716; Carl Miller O.E. Sales Manager DICO Tire Inc. 520 J.D. Yarnell Industrial Parkway Clinton TN 37716; "Dear Mr. Miller: This responds to your letter asking about th application of 49 CFR Part 574, Tire Information and Recordkeeping, to new tires sold in the replacement market. You indicated that, as a manufacturer of boat trailer tires, you believed that Part 574 required you to provide recall information cards for every new tire, whether that tire was to be installed as original equipment or sold in the replacement market. You added, however, that you heard that the National Highway Traffic Safety Administration (NHTSA) had recently restricted the application of this requirement to tires sold as original equipment. Accordingly, you requested the agency to confirm that information. NHTSA has made no amendments to Part 574 that would restrict the requirement that tire manufacturers provide recall information cards only for those tires sold as original equipment. Hence, tire manufacturers remain subject to the requirement that they provide such cards to every distributor and dealer that sells the manufacturer's new tires, regardless of whether those new tires are sold as original equipment on a vehicle or as an individual replacement item. Part 574 sets forth tire information and recordkeeping requirements to facilitate notification of purchasers in the event that a manufacturer must recall a tire to remedy a safety-related defect, or a noncompliance with an applicable Federal Motor Vehicle Safety Standard. Among Part 574's requirements, 574.7 specifies requirements for tire registration forms. I believe these forms are what your letter refers to as 'recall information cards.' 574.7 requires each new tire manufacturer and each new tire brand name owner (or its designee) to provide tire registration forms to every distributor and dealer of its tires which offers 'new tires for sale or lease to tire purchasers.' 49 CFR 574.7(a)(1) Part 574 defines 'tire purchaser' as 'a person who buys or leases a new tire, or who buys or leases for 60 days or more a motor vehicle containing a new tire for purposes other than resale.' 49 CFR 574.3(5) Thus, 574.7(a)(1) explicitly requires that tire registration forms be provided to every distributor or dealer that offers a manufacturer's new tires for sale to the public. 574.7 makes no distinction between tires to be sold as original equipment and tires sold as replacement products. For your information, I have enclosed a copy of 49 CFR Part 574 and have highlighted the provisions that relate to your question. I hope this information is helpful. Please contact Elizabeth Barbour of my staff at this address or by telephone at (202) 366-2992 if you have further questions. Sincerely, Paul Jackson Rice Chief Counsel Enclosure"; |
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ID: aiam0431OpenMr. Kenneth W. Brown, Cabot Corporation, 125 High Street, Boston, Massachusetts 02110; Mr. Kenneth W. Brown Cabot Corporation 125 High Street Boston Massachusetts 02110; Dear Mr. Brown: This is in reply to your letters of March 10 and July 1, 1971 requesting an exemption from Motor Vehicle Safety Standard No. 117 for experimental tires that you manufacture by buffing off the tread of new tires and then recapping the tires with different compounds. You state that you use these tires for testing carbon blacks by testing the tires on the public highways and on private test tracks.; We do not consider tires manufactured by the method you describe to b retreaded tires within the scope of Standard No. 117 because they are not manufactured from used tires. However, we do consider them to be new pneumatic tires, and subject to the requirements of Motor Vehicle Safety Standard No. 109. We regret that an earlier letter to you of April 7, 1971, may have been misleading in that regard.; Section 108(a)(1) of the National Traffic and Motor Vehicle Safety Ac (15 U.S.C. S1397(a)(1)) provides that no person shall --; >>>'manufacture for sale, sell, offer for sale, or introduce or delive for introduction interstate commerce... any motor vehicle or item of motor vehicle equipment manufactured on or after the date any applicable Federal motor vehicle safety standard take effect... unless it is in conformity with such standard.'<<<; We consider the testing of these tires on the public roads to be a introduction of them in interstate commerce, and prohibited by section 108(a)(1) unless the tires conform to standard No. 109. The tires need not be manufactured for sale to the general public in order for violations of section 108(a)(1) to occur. However, if the testing of these tires is confined to the laboratory or to private roads, the prohibition of the section 108(a)(1) will not apply to them.; A copy of the Act and Motor vehicle Safety Standard No. 109 is enclose for your information.; Sincerely, Lawrence R. Schneider, 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.