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: aiam0462OpenMr. K. Krueger, Technical Development, Liason (sic) Engineer, Volkswagen of America, Inc., Englewood Cliffs, NJ 07632; Mr. K. Krueger Technical Development Liason (sic) Engineer Volkswagen of America Inc. Englewood Cliffs NJ 07632; Dear Mr. Krueger: This will serve to confirm your understanding that a retractor capabl of meeting the requirements for a vehicle-sensitive emergency-locking retractor under Standard No. 209 conforms to the Standard even though it is provided with a back-up webbing-sensitive retractor that locks only at webbing accelerations greater than those specified in Standard No. 209.; Sincerely, Lawrence R. Schneider, Chief Counsel |
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ID: aiam5230OpenMr. Reuven Koter Director Baran Advanced Technologies Ltd. P.O. Box 3153 Beer Sheva 84131 Israel; Mr. Reuven Koter Director Baran Advanced Technologies Ltd. P.O. Box 3153 Beer Sheva 84131 Israel; "Dear Mr. Koter: We are replying to your FAX of July 21, 1993, to Mr Van Iderstine of this agency, and are enclosing a copy of SAE J590b as you requested. You have asked us to identify the U.S. regulations pertaining to turn signal and hazard warning signal lights including tell-tales. The applicable regulation is Federal Motor Vehicle Safety Standard No. 108, Lamps, Reflective Devices, and Associated Equipment. Standard No. 108 incorporates by reference many SAE materials, including those regarding flashers. In addition to SAE J590b (turn signal flasher, with the exceptions noted in S5.1.1.19 and S5.1.1.20 of Standard No. 108) Standard No. 108 incorporates SAE J589 (turn signal operating unit, with the exception noted in S5.1.1.13), SAE J588 (turn signal lamps for vehicles less than 2032 mm in overall width and J1395 for wider vehicles), J910 (vehicular hazard warning signal operating unit) and J945 (vehicular hazard warning signal flasher). The turn signal pilot indicator specifications are at paragraph 5.4.3 in SAE J588 and J1395. NHTSA is not contemplating rulemaking concerning any of these requirements. We understand from Mr. Van Iderstine that you are contemplating manufacturing a device that senses the sudden release of the accelerator pedal and activates the hazard warning lamp system. Under Standard No. 108, this device is permissible as original vehicle equipment (i.e. installed at the factory, or by the dealer before sale) if it does not impair the effectiveness of any of the lighting equipment that is required by Standard No. 108. We assume that the device would be automatically deactivated when the brake pedal is applied and that manual deactivation is not required. We further assume that the device is not activated under normal stopping conditions. Finally, we assume that manual activation of the turn signals will override the device should it be operating at the time the turn signal control is activated. Under these assumptions, we do not believe that the device would impair the effectiveness of the stop, tail, and turn signal lamps required by Standard No. 108. However, the judgment of impairment is one made by the person installing the device who must certify (or ensure that the certification remains valid) that the vehicle incorporating the device complies with all applicable Federal motor vehicle safety standards. Unless that judgment is clearly erroneous, NHTSA will not question it. Mr. Van Iderstine advises that no further details are currently available on ECE agenda item 'Regulation No. 48.' Sincerely, John Womack Acting Chief Counsel Enclosure"; |
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ID: aiam0032OpenMr. David Busby, Busby and Rivkin, 1001 Connecticut Ave., N.W., Washington, D.C., 20036; Mr. David Busby Busby and Rivkin 1001 Connecticut Ave. N.W. Washington D.C. 20036; Dear Mr. Busby: In your letter of July 13, 1967, you requested clarification of severa issues relating to the location and size of turn signals as specified in the Initial Federal Motor Vehicle Safety Standards. Initial Standard No. 108, entitled, 'Lamps, reflective Devices, and Associated Equipment - Multipurpose Passenger Vehicles, Trucks, Trailers, and Buses, 80 or More Inches Wide Overall,' specifies that turn signal lamps shall conform to Class A of SAE Standard J588d. As stated in the enclosures to your letter, SAE Standard J588d specifies that the optical axis (filament center) of the front turn signal lamp shall be at least 4 inches from the inside diameter of the retaining ring of the headlamp unit providing the lower beam. This requirement of the SAE Standard is addressed to a single lamp with only one bulb. For a combination of lamps, such as that shown on the sketch enclosed with your letter, the intent of this requirement could be met if the optical center produced by the two bulbs is outside the 4-inch limit. The location of this optical center must be determined from laboratory test data, which was not presented in your letter.; *Proposed* Initial Standard No. 112, entitled, 'Lamps, Reflectiv Devices, and Associated Equipment - Passenger Cars, Motorcycles, and Multipurpose Passenger Vehicles, Trucks, Trailers, and Busses of less than 80 Inches Wide Overall,' would permit the use of Class B (SAE J588d) turn signal lamps until January 1, 1969. Under this provision, lamp No. 1 on your sketch would conform to the 4-inch spacing requirement. Combining lamp no. 1 and No. 2 to obtain a Class A Area would again result in the situation previously described with respect to location of the optical center.; Since your letter makes frequent reference to 'cars,' we assume tha you are primarily interested in the requirements of Standard No. 112. In this respect, we would caution you that the requirements specified therein are presently only proposed requirements, and are subject to change prior to issuance of the final standard.; Thank you for your interest in the motor vehicle safety standards. Sincerely yours, George C. Nield, Acting Director, Motor Vehicle Safet Performance Service; |
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ID: aiam0527OpenMr. Stewart N. Metz, Crane Carrier Company, P.O. Box 4508, Tulsa, OK 74104; Mr. Stewart N. Metz Crane Carrier Company P.O. Box 4508 Tulsa OK 74104; Dear Mr. Metz: This is in response to your letter (sic) of November 16 and 30, 1971 concerning the application of Federal Motor Vehicle Safety Standard No. 206 to heavy duty trucks. You reported that you are unlikely to be able to bring the side door locks and latches on your truck into conformity with the standard until mid-1972.; In your first letter, you asked whether the standard will apply to al trucks or only those having a GVWR of more than 10,000 pounds. The standard will apply, beginning January 1, 1972, to all trucks without regard to their GVWR.; In your second letter, you requested for your trucks a temporar exemption of 180 days from the standard. We regret that we are unable to consider your request, since our authority under section 12 of the National Traffic and Motor Vehicle Safety Act (15 U.S.C. 1410) to grant such exemptions expired in April of this year.; Beginning January 1, 1972, the manufacture of any truck not i compliance with Standard 206 will be prohibited. Section 108(a) of the Act provides that; >>>'No person shall manufacture for sale . . . any motor vehicle . . manufactured on or after the date any applicable . . . standard takes effect . . . unless it is in conformity with such standard . . . ' (15 U.S.C. 1397)<<<; The prohibition is enforceable by civil penalties under section 109 (1 U.S.C. 1398) and injunction under section 110 (15 U.S.C. 1399). In addition, in the event that a noncompliance were determined to be a safety-related defect, notification of the defect would have to be furnished under section 113 (15 U.S.C. 1402).; Let us know if we may be of further assistance. Sincerely, Richard B. Dyson, Assistant Chief Counsel |
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ID: aiam4837OpenMr. Robert H. Jones President, Triple J Enterprises, Inc. P.O. Box 6066 Tamuning, Guam 96931; Mr. Robert H. Jones President Triple J Enterprises Inc. P.O. Box 6066 Tamuning Guam 96931; "Dear Mr. Jones: This responds to your letters of December 11, l990 and January 22, l99l, to Clive Van Orden of this agency, enclosing copies of your letters to Representative Blaz, dated July 6 and October 11, 1990, and to our Office of Enforcement dated July 5, l990. You have also enclosed a copy of a letter that Governor Guerrero of the Commonwealth of the Northern Mariana Islands (CNMI) wrote on your behalf on October 11, l990, to Representative Blaz. Your letter to us of July 5, l990, expresses your understanding that the Federal motor vehicle safety standards (FMVSS) apply in the CNMI, and that you, as an importer, have imported only vehicles that are certified as conforming to the FMVSS, however, certain of your competitors have not. You asked 'Will I get compliance enforcement? Or should I join the competition and bring in the vehicles that do not comply?' To similar effect is your letter of the next day to Representative Blaz. Governor Guerrero's letter to Mr. Blaz expresses his opinion that the FMVSS do not apply in the CNMI. The Governor explains: By our Covenant with the United States, we were obliged to except NHTSA believes he means 'accept' federal laws that applied to Guam and the several states as of January 9, 1978. Federal enabling legislation behind the FMVSS has been on the books since l966. The legislation applied to Guam and the states on January 9, 1979 sic . It looks like we get the law. But that is not the end of the analysis. We would accept application of the FMVSS here only if such federal law did not deny us our guaranteed right of local self-government with respect to internal affairs. It is my view that automobile safety is an internal affair. It is the subject for self- government. The Federal Motor Vehicle Safety Standards do not apply in the CNMI. These federal safety standards are imposed on the states by virtue of the Commerce clause of the Federal Constitution. The federal Commerce clause does not apply in the CNMI, it cannot carry the FMVSS into our islands. I t is our position that the FMVSS does sic apply here and will not be enforced by my Administration. We cannot agree with the Governor's conclusion. The National Traffic and Motor Vehicle Safety Act of l966 (l5 U.S.C. 1381 et seq.), does apply in the CNMI, as do all regulations such as the FMVSS that are issued under the authority of that law. The Governor believes that 'automobile safety is an internal affair'. For the most part we agree, but not with respect to the primacy of the FMVSS. We agree that vehicle registration, taxation, and use of the roads in the CNMI are matters properly under the jurisdiction of the CNMI. Further, the Act permits local jurisdictions to enact or continue in effect their own vehicle safety standards provided that they do not differ from the FMVSS (except as may apply to their own official vehicles). The FMVSS are manufacturing standards that apply when the vehicles are built, imported, and sold. We are sorry that your observance of the law may have put you at a competitive disadvantage. If you have specific information regarding possible violations of the importation provisions of the Act in the CNMI including the names and addresses of specific businesses or individuals, please communicate that information to Mr. Van Orden. Our sources of information are kept confidential. Although the FMVSS apply in the CNMI, it is obvious that enforcement of them by this agency is made more difficult by the absence of agency staff in the CNMI. If local government would 'move for immediate adoption of those standards ... by local law', then they may be enforced locally. I cannot think of a single one of the FMVSS that would not be of benefit. Although speeds may be low on the roads of the CNMI, many of the FMVSS are intended to provide crash protection at 30 m.p.h. Obviously, FMVSS that pertain to vehicle lighting, windshield wiping and washing, etc. provide protection at any speed. We appreciate your bringing this matter to our attention. Sincerely, Paul Jackson Rice Chief Counsel cc: Thomas Rabago Highway Safety Coordinator"; |
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ID: aiam0177OpenHonorable William Proxmire, United States Senate, Washington, DC 20510; Honorable William Proxmire United States Senate Washington DC 20510; Dear Senator Proxmire: Thank you for your letter of August 27, 1969, to the Director Legislative Liaison, Department of Transportation, concerning Mr. Eugene J. Shermeister's comments on headlamps for motor vehicles.; Enclosed for Mr. Shermeister's information is a copy of Federal Moto Vehicle Safety Standard No. 108 on lighting requirements for the vehicles specified in the standard. Standard No. 108 is applicable to new vehicles manufactured on or after the effective date of January 1, 1969. In accordance with the National Traffic and Motor Vehicle Safety Act of 1966, the initial safety standards were based on existing standards. Headlighting requirements, as specified in Standard No. 108, were therefore based on existing Bureau of Motor Carrier Safety Regulations, certain State regulations and the Society of Automotive Engineers (SAE) Standards. On this basis, Standard No. 108 specifies that headlamps for all vehicles except motorcycles conform to SAE Standards J579a and J580a, entitled, respectively, 'Sealed Beam Headlamp Units for Motor Vehicles' and 'Sealed Beam Headlamp.' To provide protection from blinding effects to oncoming drivers, SAE Standard J579a specifies a maximum lamp output of 37,500 candlepower. This candlepower value is considerably less than the candlepower output of quartz iodine type headlamps.; As indicated in paragraph S2 of Standard No. 108, the standard i applicable to lighting on new vehicles and not to replacement lighting equipment. Except for vehicles subject to the Bureau of Motor Carrier Safety Regulations, the requirements for replacement lighting equipment, as well as lighting requirements for vehicles in use, are those requirements as set by the regulatory agencies of the individual states.; The National Highway Safety Bureau is sponsoring a research contract o improved forward lighting for motor vehicles. Results of this contract will not only provide us with well-founded data for use in amending the standard, but will also assist us in evaluating the relative merits of sealed beam, quartz iodine and other types of headlamps.; Sincerely, W. M. Jacklin, Jr., Acting Director, Motor Vehicle Safet Performance Service; |
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ID: aiam5375OpenMr. Len R. Thies C&C Creations 9103 East 67th Court Tulsa, OK 74133; Mr. Len R. Thies C&C Creations 9103 East 67th Court Tulsa OK 74133; "Dear Mr. Thies: This responds to your letter asking about Federa rules, particularly those for flammability resistance, applicable to your aftermarket product. I apologize for the delay in responding. You state that your product is a sheet of clear vinyl that inhibits the air flow in a van, thus reducing the amount of air to be heated or cooled. You further state that your product does not impair visibility and that it is easily detached and removed by the vehicle owner. This response is based on our understanding of the facts presented in your letter. 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 National Traffic and Motor Vehicle 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, you are required to certify that your device complies with Standard No. 205, Glazing Materials (49 CFR 571.205), based on our understanding of your letter. Standard No. 205 applies to new, completed vehicles as well as to glazing sold in the aftermarket. The standard establishes performance requirements for various types of glazing (called 'items') and specifies the locations in vehicles in which each item of glazing may be used. The standard also incorporates by reference 'ANSI Z26,' the American National Standards Institute's 'Safety Code for Safety Glazing Materials for Motor Vehicles Operating on Land Highways.' It appears that your device may be considered an 'interior partition,' which is considered under ANSI Z26 to be item 6 glazing. In addition, if your product were manufactured for a new vehicle, the vehicle would have to be certified as complying with Standard No. 111, Rearview Mirrors and Standard No. 302, Flammability of Interior Materials, in addition to Standard No. 205. However, Standards No. 111 and No. 302 apply only to new vehicles, and not to items of aftermarket motor vehicle equipment. Thus, they do not apply to your product. I note, however, that there are other Federal requirements that indirectly affect the manufacture and sale of your product. Under the Safety Act, your product is considered to be an item 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 product contains a safety-related defect, you would be responsible for notifying purchasers of the defective equipment and remedying the problem free of charge. 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 ....' Your vinyl sheet could render inoperative the rearward visibility requirements set forth in Standard No. 111, or the light transmittance requirements set forth in Standard No. 205. In addition, your product could have elements of design that could render inoperative a vehicle's compliance with Standard No. 302, the FMVSS for flammability resistance for materials used in the occupant compartment of motor vehicles. While it appears unlikely that persons in the aforementioned categories would be installing your product, if they were to install it, they must not compromise the rearward visibility or flammability resistance provided by the motor vehicle. 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, they would not need to meet any FMVSSs. Nevertheless, NHTSA urges vehicle owners not to tamper with or degrade the safety of their vehicles. 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: aiam1336OpenMr. R.O. Crider, Manager, Government Safety Standards and Regulations Compliance, Fruehauf Corporation, P.O. Box 238, Detroit, MI 48232; Mr. R.O. Crider Manager Government Safety Standards and Regulations Compliance Fruehauf Corporation P.O. Box 238 Detroit MI 48232; Dear Mr. Crider: Thank you for your letter of November 20, 1973, asking whether you ma install 'lights as set forth in Example 1.' In this example identification lamps would be mounted under the rear crossmember of the vehicle while 'the combination tail and turn signal lamps (at the bottom) could serve as the clearance lamps.'; The rear lighting scheme shown in your 'Example 1' appears to b seriously at variance with Standard No. 108. There is a clear violation of paragraph S4.4.1 which forbids the optical combination of tail lamps and clearance lamps. Both clearance lamps and identification lamps must be located 'as close as practicable to the top of the vehicle.' The fact that you have developed a clearance lamp that can be mounted in the header area demonstrates that that is the 'practicable' location, despite the fact that the header may be too shallow to accommodate the lamps specified by the customer. Further, since the performance required of clearance lamps is identical to that for identification lamps, and three of your clearance type lamps could serve as identification lamps, the header would appear to be the 'practicable' location for the identification lamp arrangement as well.; Sincerely, Lawrence R. Schneider, Chief Counsel |
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ID: aiam4134OpenMr. Bob Quick, 1830 North Ridge Street, Coralville, IA 52241; Mr. Bob Quick 1830 North Ridge Street Coralville IA 52241; Dear Mr. Quick: Thank you for your recent telephone call in which you asked whether i would be legally permissible for an odometer which is being installed in your automobile to replace one that was registering high mileage to be set at the mileage that the automobile was actually driven. There is regrettably no means for this to be done under the Federal odometer law. Section 407 of the Motor Vehicle Information and Cost Savings Act, as found in 15 U.S.C. 1987, permits the 'replacement of an odometer, provided the mileage indicated thereon remains the same as before the . . . replacement.' No adjustments are permitted to compensate for any excess mileage that may have registered on the odometer being replaced. Although some may regard this as being unduly stringent, the creation of such a loophole could invite fraudulent abuse and seriously undermine the effectiveness of our odometer enforcement program.; Enclosed for your information is a copy of the statute and regulation that establish odometer requirements, together with a fact sheet that we have prepared on the subject.; If we can be of any further assistance, please feel free to contact u again.; Sincerely, David W. Allen, Assistant Chief Counsel |
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ID: aiam2849OpenMr. F. Michael Petler, Assistant Manager, Safety & Legislation Dept., U.S. Suzuki Motor Corporation, 13767 Freeway Drive, Santa Fe Springs, CA 90670; Mr. F. Michael Petler Assistant Manager Safety & Legislation Dept. U.S. Suzuki Motor Corporation 13767 Freeway Drive Santa Fe Springs CA 90670; Dear Mr. Petler: This is in reply to your letter of August 10, 1978, asking for a interpretation of Motor Vehicle Safety Standard No. 108. You have asked 'whether an aftermarket Class A reflex reflector can be installed in addition to the original Equipment Class A reflex reflector, that is, an existing part of the motorcycle's rear combination lamp assembly.' You have stated that 'both reflectors would be installed vertically on the motorcycles vertical centerline,' and have commented that you understand 'that two reflectors may be installed horizontally about the vertical centerline, but it is unclear to us whether they may both be installed one on top of the other, vertically, as this is not addressed in FMVSS No. 108.'; You have misunderstood Standard No. 108. Table IV clearly states wit respect to location of rear reflex reflectors on motorcycles that 'if two are used on the rear, they shall be symmetrically disposed about the vertical centerline.' This requirement precludes the use of two rear reflectors mounted above each other vertically on the vehicle's centerline if your fender extension is sold as an accessory on a motorcycle at the time of its first purchase for purposes other than resale.; Generally, however, Federal standards do not cover vehicles after thei first purchase and an owner may modify his vehicle in any manner he chooses consistent with local law. Modification by dealers, distributors, and repair businesses are prohibited only if they 'render inoperative' any device or element of design installed on a motor vehicle in accordance with a Federal safety standard. Although aftermarket installation of the fender with reflector by a dealer after a vehicle's sale would not be consistent with the reflector location requirements of Standard No. 108, we cannot say that it would 'render inoperative' the reflector installed as original equipment. We therefore have no objection to you offering this component as an aftermarket accessory to be added after a vehicle's initial sale.; Sincerely, Joseph J. Levin, Jr., 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.