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: aiam2766OpenMr. William J. Wood, Nebraska Dept. of Motor Vehicles, Statehouse Station 94612, Lincoln, NE 68509; Mr. William J. Wood Nebraska Dept. of Motor Vehicles Statehouse Station 94612 Lincoln NE 68509; Dear Mr. Wood: This responds to your January 16, 1978, letter asking several question about the applicability of the school bus regulations to school buses manufactured after April 1, 1977, transporting 10 or more students to or from school or related events.; You first ask whether these buses must be painted yellow and hav school bus lighting and markings. The answer to your question is yes. Any vehicle that transports 10 or more students to or from school or related events is a school bus and must have the painting, marking, and lighting of a school bus.; Your second question is whether smaller school buses (vans) ar permitted to have van-type seats or must comply with the requirements of Standard No. 222, *School Bus Passenger Seating and Crash Protection*. A vehicle that transports 10 or more students must comply with all of the Federal school bus regulations, including the seating standard.; Sincerely, Joseph J. Levin, Jr., Chief Counsel |
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ID: aiam5109OpenMr. Rodney T. Nash, P. E. Vice President Engineering Collins Industries, Inc. 421 East 30th Avenue Hutchinson, KS 67502-2493; Mr. Rodney T. Nash P. E. Vice President Engineering Collins Industries Inc. 421 East 30th Avenue Hutchinson KS 67502-2493; "Dear Mr. Nash: This responds to your letter to the Administrator National Highway Traffic Safety Administration (NHTSA), received in this office on November 18, 1992, and your telephone conversation of November 30, 1992 with Walter Myers of this office, regarding the proper classification of an ambulance. You indicated that Wheeled Coach Industries of Orlando, Florida, a subsidiary of Collins Industries, produces ambulances that are built on truck chassis. You stated that in the past those vehicles have been classified as trucks, but that Ford Motor Company auditors told you that they should be classified as multipurpose passenger vehicles (MPV). You said that you needed to know how to classify ambulances, observing that it appeared to you that the final stage manufacturer was free to choose between the two classifications, truck or MPV. NHTSA has long considered ambulances to be multipurpose passenger vehicles, which are defined in 49 Code of Federal Regulations (CFR) 571.3 as 'a motor vehicle with motive power, except a trailer, designed to carry 10 persons or less which is constructed either on a truck chassis or with special features for occasional off-road operation.' Your company's ambulances fit this definition very well: they are mounted on a truck chassis and are designed to carry ten persons or less. As you pointed out in your letter, it is true that an ambulance may carry more weight in special equipment than it carries in patients, and it may operate half its life with no patient on board. Nevertheless, NHTSA believes that whether or not a patient is on board or how much equipment is carried, the vehicle is primarily designed for the transportation and/or care of ill or injured persons, as well as the transportation of paramedic personnel to wherever they are needed. This is in contrast to a truck which is defined also in 49 CFR 571.3 as 'a motor vehicle with motive power, except a trailer, designed primarily for the transportation of property or special purpose equipment'. Thus, although an ambulance carries special purpose equipment, NHTSA believes that the equipment is only ancillary to the primary function of an ambulance which is the transportation of persons. Accordingly, an ambulance falls within the definition of MPV rather than truck. I hope this will help clarify this issue for you. Should you have any further questions in this regard, please feel free to contact Mr. Myers at this address or at (202) 366-2992. Sincerely, Stephen P. Wood Assistant Chief Counsel for Rulemaking"; |
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ID: aiam2336OpenMr. K. Nakajima, Director/General Manager, Factory Representative Office, Toyota Motor Sales, U.S.A., Inc., 1099 Wall Street, West Lyndhurst, NJ 07071; Mr. K. Nakajima Director/General Manager Factory Representative Office Toyota Motor Sales U.S.A. Inc. 1099 Wall Street West Lyndhurst NJ 07071; Dear Mr. Nakajima: This is in response to your March 24, 1976, letter, concerning th label required by S 567.4(g) of 49 CFR Part 567, *Certification*.; The certification label is required by paragraph (g)(3) to includ ''GROSS VEHICLE WEIGHT RATING' or 'GVWR' followed by the appropriate value in pounds...' Paragraph (g)(4) specifies a similar requirement for Gross Axle Weight Rating.; You have pointed out that the Canadian motor vehicle safety regulation require a similar certification label with these weight ratings expressed in kilograms. You have asked whether a single label that expresses the weight ratings in both pounds and kilograms would be permitted by 49 CFR Part 567. The answer is yes, provided that each kilogram rating, which is optional, appear after the corresponding pound rating, which is required.; Please note that these two ratings differ in legal status. The ratin that is expressed in pounds is the official rating for the purposes of the United States Federal motor vehicle safety standards and regulations. The accompanying equivalent kilogram rating, however, will be considered as optional, supplementary information provided for the guidance of the reader. This distinction is necessary, because the measurement values, including weights, that appear in our safety standards and regulations are specified in exact terms, without tolerances. While a measurement in English units can be 'equal' to one in metric units to any preselected number of significant figures, the two can never be exactly equal.; Yours truly, Frank Berndt, Acting Chief Counsel |
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ID: aiam4431OpenMr. Hiroshi Kato MMC Services Inc. 3000 Town Center Suite 1960 Southfield, MI 48075; Mr. Hiroshi Kato MMC Services Inc. 3000 Town Center Suite 1960 Southfield MI 48075; "Dear Mr. Kato: This is in response to your letter of April 19, 1988 concerning whether a Mitsubishi Motors Corporation SH27 lightweight industrial truck that you intend to offer for sale in the United States should be classified as a motor vehicle under Section 102(3) of the National Traffic and Motor Vehicle Safety Act ('Safety Act'). You stated that this vehicle is intended for 'general or carrier work for off-road applications,' and that it is capable of a maximum speed of approximately 25 mph. You further explained that your company planned to advertise, promote, and market this vehicle as an off-road vehicle. Based on the information provided in your letter, it appears that the SH27 would not be a motor vehicle under the Safety Act. Section 102(3) of the Safety Act (15 U.S.C. 1391(3)) defines a 'motor vehicle' as any vehicle driven or drawn by mechanical power manufactured primarily for use on the public streets, roads, and highways, except any vehicle operated exclusively on a rail or rails. NHTSA has interpreted this language as follows. Vehicles that are equipped with tracks or are otherwise incapable of highway travel are plainly not motor vehicles. Further, vehicles designed and sold solely for off-road use (e.g., airport runway vehicles and underground mining devices) are not considered motor vehicles, even though they may be operationally capable of highway travel. Vehicles that have an abnormal body configuration that readily distinguishes them from other highway vehicles and a maximum speed of 20 miles per hour (mph) are not considered motor vehicles, because their use of the public roads is intermittent and incidental to their primary intended off-road use. On the other hand, vehicles that use the public highways on a necessary and recurring basis are motor vehicles. For instance, a utility vehicle like the Jeep is plainly a motor vehicle, even though it is equipped with special features to permit off-road operation. If a vehicle's greatest use will be off-road, but it will spend a substantial amount of time on-road, then NHTSA has interpreted the vehicle to be a 'motor vehicle'. Further, the agency has determined that a vehicle such as a dune buggy is a motor vehicle if it is readily usable on the public roads and is in fact used on the public roads by a substantial number of owners, regardless of the manufacturer's stated intent regarding the terrain on which the vehicle is to be operated. Your vehicle is not easily classified under either of these groupings. On the one hand, your vehicle has a body configuration nearly identical to standard trucks, can be registered for use on the highways of several foreign countries, and can obtain a a maximum speed of approximately 25 mph. These factors suggest that the vehicle should be classified as a motor vehicle. On the other hand, you stated that this vehicle is intended to be used only for off-road applications and that this vehicle will be advertised and promoted for off-road purposes only and will contain four warning labels stating 'Warning: Off Road Use Only.' These factors suggest that the vehicle should not be classified as a motor vehicle. In instances where the agency is asked whether a vehicle is a motor vehicle when it has both off-road and on-road operating capabilities, and about which there is little or no evidence about the extent of the vehicle's on-road use, the agency has applied five factors in offering its advice. These factors are: 1. Whether States or foreign countries have permitted or are likely to permit the vehicle to be registered for on-road use. You noted that several foreign countries including Japan and Taiwan register for on-road use the general export configuration of this vehicle. This suggests that your vehicle should be considered a motor vehicle. You attempted to distinguish this fact by stating that the vehicle to be sold in the United States has different specifications than the general export vehicles. The differences are that the United States version has a maximum speed of 25 mph while the general export version can achieve speeds of greater than 55 mph, the engine displacement in the United States version has an engine of 548 cc rather than the 796 and 783 cc for the general export version, and the United States version has an hourmeter (similar to agricultural vehicles) rather than a speedometer. You stated that these differences mean that there is little basis for assuming that the experience in other countries would correlate to the likelihood of States permitting the vehicle to be registered for highway use in the United States. Since the vehicle closely resembles a small truck for highway use, we believe it is likely that States would permit it to be registered for highway use, just as other countries have. Therefore, this factor suggests that your vehicle should be considered a motor vehicle. 2. Whether the vehicle is or will be advertised for use on-road as well as off-road, or whether it is or will be advertised exclusively for off-road use. You stated that your advertising and promotional materials will state that your vehicle should be used only for off-road purposes and will not depict or suggest that the vehicle can be used on-road. This factor suggests that the vehicle should not be considered a motor vehicle. 3. Whether the vehicle's manufacturer or dealers will assist vehicle purchasers in obtaining certificates of origin or title documents to register the vehicle for on-road use. You stated that your dealers will be instructed that this vehicle is to be used solely for off-road purposes and that no assistance should be given to obtain a title for the vehicle or to register the vehicle in this country. Your company also will state on any ownership document that this vehicle is not intended for on-road use. Therefore, this factor would indicate that the vehicle should not be considered a motor vehicle. 4. Whether the vehicle is or will be sold by dealers also selling vehicles that are classified as motor vehicles. You stated that this vehicle will only be sold by dealerships that sell vehicles other than motor vehicles, such as material handling equipment like lifts and agricultural equipment. This factor suggests that the vehicle should not be considered a motor vehicle. 5. Whether the vehicle has or will have affixed to it a warning label stating that the vehicle is not intended for use on the public roads. You stated that four warning labels will be affixed to the interior and exterior of the vehicle body. Labels stating 'Off Road Use Only' will be applied to the exterior front panel of the cab, the rear gate, and the instrument panel. Additionally, a label stating 'Warning: Off Road Use Only' will be affixed to the exterior rear panel of the cab. This factor would indicate that the vehicle is not a motor vehicle. Based on the representations in your letter, the agency believes that the Mitsubishi SH27 lightweight truck does not appear to be a motor vehicle under the Safety Act. However, we will reexamine this conclusion if we learn that, for example, the vehicle is in fact used on the public roads by a substantial number of its owners. I hope this information is helpful. Sincerely, Erika Z. Jones Chief Counsel /"; |
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ID: aiam1633OpenMr. F.S. Vukan, B.F. Goodrich Tire Company, 500 South Main Street, Akron, Ohio 44318; Mr. F.S. Vukan B.F. Goodrich Tire Company 500 South Main Street Akron Ohio 44318; Dear Mr. Vukan: #This is in further reply to your letter of August 21 1974, asking whether tires manufactured by B.F. Goodrich that are filled with 'Tyrfil' will be subject to the requirements of Motor Vehicle Safety Standard No. 119. #On the basis of the information you have provided, we have determined that tires filled with Tyrfil are not 'pneumatic' tires, and are therefore subject neither to the requirements of Standards Nos. 109 nor 119. We find that Tyrfil, which is a solid polyurethane, differs significantly as a tire-filling medium from cellular foam, whose use has been determined to be within the scope of Standards Nos. 109 and 119 (37 FR 24908, November 23, 1972). #Sincerely, Robert L. Carter, Associate Administrator, Motor Vehicle Programs; |
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ID: aiam0921OpenMr. R. B. Smith, Finance Manager, Bluefield Mack Trucks, Inc., 536 Bluefield Avenue, Bluefield, West VA 2470l; Mr. R. B. Smith Finance Manager Bluefield Mack Trucks Inc. 536 Bluefield Avenue Bluefield West VA 2470l; Mr. R. B. Smith: This is in reply to your letter of November 17, 1972, requestin information on alteration, and installation of fifth wheels, on new trucks.; Persons who install fifth wheels on new trucks are generally considere to be 'final-stage manufacturers' under NHTSA Certification regulations, and are required to certify that vehicles on which they install the fifth wheel conform to applicable Federal standards. The NHTSA has recently proposed requirements regarding persons who alter completed vehicles, and a copy of this proposal is enclosed.; Copies of NHTSA requirements maybe obtained as indicated on th enclosure, 'Where to Obtain Motor Vehicle Safety Standards and Regulations.' The regulations regarding the certification of motor vehicles are found at Parts 567 and 568 of Title 49 of the Code of Federal Regulations, (Item 1) and of the volume, 'Federal Motor Vehicle Safety Standards and Regulations' (Item 3).; Yours truly, Richard B. Dyson, Assistant Chief Counsel |
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ID: aiam4061OpenMr. Patrick R. McCreary, General Manager, Van Patton Vans, 22865 Pine Creek Road, P.O. Box 1305, Elkhart, IN 46515; Mr. Patrick R. McCreary General Manager Van Patton Vans 22865 Pine Creek Road P.O. Box 1305 Elkhart IN 46515; Dear Mr. McCreary: This responds to your recent letter concerning the manufacturin operations you intend to perform on Ford Econoline vans. In a December 16 telephone conversation with Ms. Hom of my staff, you explained that the vans are incomplete vehicles which you will be receiving from a Ford dealership prior to the vehicles' first sale. A company other than your own will 'stretch' the vehicles 48 to 60 inches, but your company will be completing the manufacture of the vehicle by adding seats (for 20 passengers), windows, carpeting, and so forth. You asked what your responsibilities would be under NHTSA's regulations and safety standards.; Under our regulations, a motor vehicle designed for carrying more tha 10 persons is a 'bus' (Part 571.3). Since the vans, as completed, will meet that definition, the applicable safety standards for the vehicle you will be producing are those applying to buses. If you are performing manufacturing operations on an incomplete vehicle, as that term is defined in Title 49 of the Code of Federal Regulations (CFR) Part 568.3, so that it becomes a completed vehicle, then Part 568, *Vehicles manufactured in two or more stages*, sets forth the requirements you must meet. Under 568.6, Van Patton Vans, as the 'final-stage manufacturer,' would be required to complete the vehicle in such a manner that it conforms to all safety standards for buses in effect on a date no earlier than the manufacturing date of the incomplete vehicle, and no later than the date of completion of the final-stage manufacture. Also, your company must affix a label to the completed vehicle in accordance with the certification requirements set forth in Part 567.5, *Requirements for manufacturers of vehicles manufactured in two or more stages*.; I have enclosed copies of 49 CFR Parts 567 and 568, for you convenience. I have also enclosed an information sheet that describes how you can obtain copies of NHTSA's regulations and motor vehicle safety standards. Please contact my office if you have further questions.; Sincerely, Erika Z. Jones, Chief Counsel |
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ID: aiam1799OpenMr. Bruce H. Multhaup, Administrative Engineer, TRW, Inc., 23555 Euclid Avenue, Cleveland, OH 44117; Mr. Bruce H. Multhaup Administrative Engineer TRW Inc. 23555 Euclid Avenue Cleveland OH 44117; Dear Mr. Multhaup: This responds to TRW's January 24, 1975, question whether S4.1(k) o Standard No. 209, *Seat belt assemblies*, requires separate labeling of both parts of a Type II seat belt assembly in those cases where webbing is used on both the 'tongue' and 'receptacle' sides of the assembly. You enclose a photograph of the seat belt assembly in question.; Section S3. defines 'Seat belt assembly' as 'any strap, webbing o similar device designed to secure a person in a motor vehicle in order to mitigate the results of any accident, including all necessary buckles and other fasteners...' The use of the word 'assembly' and the reference to 'buckles and other fasteners' makes clear that a seat belt assembly can be composed of more than one part.; Section S4.1(k) specifies that 'Each seat belt assembly' shall b permanently and legibly marked or labeled with certain information. This means that one label is required on each assembly, regardless of the number of components which constitute the assembly.; Therefore, so long as the two portions of a seat belt assembly are i fact designed for use in combination to secure a person in a motor vehicle in order to mitigate the results of any accident, one label satisfies the requirements of S4.1(k).; Yours truly, Richard B. Dyson, Assistant Chief Counsel |
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ID: aiam1263OpenHonorable James R. Jones, House of Representatives, Washington, DC 20515; Honorable James R. Jones House of Representatives Washington DC 20515; Dear Mr. Jones: This is in reply to your letter of July 23, 1973, forwarding to u correspondence from Mr. G. N. Nichols, President, Midwestern Products, Incorporated, Tulsa, concerning the applicability of Federal regulations to an air suspension auxiliary axle manufactured by Midwestern Products. According to the manufacturer's advertising brochure, this axle, the 'Micro- Air Retractable Safety Axle,' is intended to be used on pick-up and bobtail trucks, particularly in the recreational vehicle and related fields.; There are presently no Federal motor vehicle safety standards o regulations that apply to the manufacture of these axles. However, persons who install them on *new* pick-up trucks or other vehicle types (a 'new vehicle under the National Traffic and Motor Vehicle Safety Act is one that has not yet been sold to a user) may be considered as vehicle alterers under provisions of NHTSA certification regulations which are to become effective February 1, 1974 (Docket No. 72-27, copy enclosed), and would be required to affix to the vehicle the label described in section 567.7 of those regulations.; Midwestern Products should be aware of these requirements whether i installs the Micro-Air axle or whether the installation is done by other parties. In the former case Midwestern would be responsible for affixing the required label, and in the latter it should provide the relevant information for the label regarding weight ratings to the party making the installation.; The NHTSA does not maintain a mailing list to provide copies of NHTS notices and regulations. Copies are available as indicated on the enclosed sheet, 'Where to Obtain Motor Vehicle sAfety Standards and Regulations.'; We are pleased to be of assistance. Sincerely, Robert L. Carter, Associate Administrator, Motor Vehicl Programs; |
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ID: aiam5220OpenMr. Han Dinh Project Manager United States Postal Service 8403 Lee Highway Merrifield, VA 22082-8101; Mr. Han Dinh Project Manager United States Postal Service 8403 Lee Highway Merrifield VA 22082-8101; "Dear Mr. Dinh: This responds to your letter requesting informatio about the conversion of postal vehicles to operate on compressed natural gas (CNG). You explained that you are deciding which specifications to apply to the CNG pressure vessels on the converted vehicles. You ask whether we would recommend the American Gas Association's voluntary standard, NGV-2, or the Department of Transportation standard for cylinders which transport CNG. By way of background, the National Highway Traffic Safety Administration (NHTSA) is authorized under the National Traffic and Motor Vehicle Safety Act (15 U.S.C. 1381 et seq., Safety Act) to issue Federal motor vehicle safety standards that set performance requirements for new motor vehicles and items of motor vehicle equipment. NHTSA does not 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. NHTSA also investigates safety- related defects in motor vehicles and items of motor vehicle equipment. At present, NHTSA has not issued any standard applicable to CNG cylinders or vehicles using CNG as a fuel. However, as you know, NHTSA has undertaken rulemaking on a safety standard for CNG tanks and vehicles. (58 FR 5323, January 21, 1993.) In response to our January 1993 proposal, the agency received over 55 comments, which we are currently analyzing. We expect our next regulatory decision in early 1994. Given that this rulemaking has not been completed, NHTSA is unable to recommend to you a particular course of action with respect to the NGV-2 and DOT standards at this time. If NHTSA were to issue a safety standard for CNG cylinders and vehicles, the standard would apply to new products, and have applicability to vehicle conversions as follows. The cylinder regulation would be an equipment standard. Thus, all cylinders manufactured after the effective date of the standard would be required to comply with its requirements, whether they are placed on new vehicles or on vehicles converted to CNG fuel. The fuel system regulation would apply to new vehicles as manufactured by original equipment manufacturers or as converted prior to the first sale of the vehicle. Once the vehicle is sold, if the vehicle is converted by a commercial converter, the CNG fuel system regulation would apply if the vehicle was manufactured after the effective date of the standard and thus would have been regulated if it had originally been a CNG vehicle. With this in mind, I have enclosed a discussion that sets forth the implications under Federal law of converting gasoline-powered vehicles to use propane or other gas (such as CNG). That discussion addresses 108(a)(2)(A) of the Safety Act, which prohibits vehicle manufacturers, distributors, dealers and repair businesses from 'knowingly rendering inoperative, in whole or in part, any device or element of design installed . . . in compliance' with any FMVSS. In addition, please be aware that manufacturers of CNG tanks and vehicles are subject to the requirements in sections 151-159 of the Safety Act concerning the recall and remedy of products with defects related to motor vehicle safety. In the event that NHTSA or the manufacturer of the tank or vehicle determines that the product contains a safety- related defect, the manufacturer would be responsible for notifying purchasers of the defective equipment and remedying the problem free of charge. Our sister agency in the Department, the Federal Highway Administration (FHWA), has operational and equipment requirements for commercial vehicles used in interstate commerce. For further information about FHWA requirements, you can contact that agency's Chief Counsel's office at (202) 366-0650. I hope you find this information helpful. If you have any other questions, please contact Marvin Shaw of my staff at this address or by phone at (202) 366-2992. Sincerely, John Womack Acting Chief Counsel Enclosure"; |
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.