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: 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"; |
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ID: aiam0022OpenMr. David A. Phelps, Jr., Engineering Services, Blue Bird Body Company, Fort Valley, GA 31030; Mr. David A. Phelps Jr. Engineering Services Blue Bird Body Company Fort Valley GA 31030; Dear Mr. Phelps: In response to your letter of May 12, 1967, regarding th classification of your Blue Bird Wanderlodge, I have enclosed a copy of the Initial Federal Motor Vehicle Safety Standards. On page 2408 of this document, 'Bus' is defined as a motor vehicle with motive power, except a trailer, designed for carrying more than 10 persons. With the assumption that your Wanderlodge does have seating capacity for more than 10 people, it would therefore be classified as a bus.; Thank you for your interest in the motor vehicle safety program of thi Bureau.; Sincerely yours, George C. Nield, Acting Director, Motor Vehicle Safet Performance Service; |
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ID: aiam0188OpenMr. Heinz C. Hoppe, Executive Vice President, Mercedes-Benz of North America, Inc., 158 Linwood Plaza, Fort Lee, NJ 07024; Mr. Heinz C. Hoppe Executive Vice President Mercedes-Benz of North America Inc. 158 Linwood Plaza Fort Lee NJ 07024; >>>Re: Consumer Information<<< Dear Mr. Hoppe: We have received your submittal of consumer information in response t the requirements of 49 CFR Part 375. That regulation requires that manufacturers submit their information to the Administrator 30 days in advance of the time it is made available to prospective purchasers. Since we have not required that this advance submittal be in the same form as that given to purchasers, the following comments are only advisory in nature. There is one respect, however, in which the information, if supplied in this form to prospective purchasers, would not satisfy the requirements of the regulations.; The Consumer Information section on Vehicle Stopping Distance, 49 CFR 375.101, specifies that the information presented shall contain 'the most adverse combination of maximum or lightly loaded vehicle weight and complete logs of braking in any one of the vehicle brake subsystems.' In your submittal, you have presented information for failures in each of the front and rear subsystems, instead of selecting the most adverse combination of weights and system failures. This is likely to confuse consumers attempting to compare vehicles of different manufacturers, and fails to satisfy the requirement that the information shall be submitted 'in essentially the form illustrated in Figure 1' of S 375.101.; We will be glad to answer any questions that you may have with respec to the requirements of these or other motor vehicle safety regulations and standards.; Sincerely, Robert Brenner, Acting Director |
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ID: aiam4962OpenMr. Frederick Harris Frederick Harris Associates 5717 Huberville Avenue Dayton, Ohio 45431; Mr. Frederick Harris Frederick Harris Associates 5717 Huberville Avenue Dayton Ohio 45431; "Dear Mr. Harris: This responds to your letter asking about Federa motor vehicle safety standards applicable to your product, which you described as a cloth device containing plastic items useful to a baby, for use in motor vehicles. You explained that your product would be placed in a motor vehicle adjacent to, but not touching, a child in a nearby child safety seat. In particular, you were concerned about flammability resistance standards applicable to your product. I am pleased to have this opportunity to explain our requirements to you. I am also enclosing a copy of a fact sheet entitled 'Information for New Manufacturers of Motor Vehicles and Motor Vehicle Equipment.' 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. Section 102(4) of the Safety Act defines, in relevant part, the term 'motor vehicle equipment' as: any system, part, or component of a motor vehicle as originally manufactured or any similar part or component manufactured or sold for replacement or improvement of such system, part, or component or as any accessory, or addition to the motor vehicle ... In determining whether an item of equipment is considered an accessory, NHTSA applies two criteria. The first criterion is whether a substantial portion of the expected use of the item is related to the operation or maintenance of motor vehicles. We determine the expected use by considering product advertising, product labeling, and the type of store that retails the product, as well as available information about the actual use of the product. The second criterion is whether the product is intended to be used principally by ordinary users of motor vehicles. If the product satisfies both criteria, then the product is considered to be an 'accessory' and thus is subject to the provisions of the Safety Act. Applying these criteria to the cloth device containing baby items, it appears that your product would be an accessory and thus an item of motor vehicle equipment under the Safety Act. Based on our understanding of your device, it appears that a substantial portion of its expected use will be during the operation of a motor vehicle. In a telephone conversation with Ms. Dee Fujita of my staff, you explained that your device is intended to be sold for use in motor vehicles. In addition, it appears that your product would typically be used by ordinary users of motor vehicles. While it appears that your device would be considered an item of motor vehicle equipment, this agency has not issued any standards setting forth performance requirements for such a device. Obviously, your device could not be determined to be in noncompliance with a safety standard if there is no applicable safety standard. As for your concern about flammability resistance requirements, please be advised that our safety standard about this issue, Standard No. 302, Flammability of Interior Materials, (49 CFR 571.302, copy enclosed), would not apply to your device. That standard sets forth such requirements applicable to new motor vehicles and not to motor vehicle equipment. You should be aware that, as a manufacturer of an aftermarket item of motor vehicle equipment, you 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 you or NHTSA determines that your product contains a safety related defect, you would be responsible for notifying purchasers of the defective equipment and for remedying the problem free of charge. 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, Paul Jackson Rice Chief Counsel Enclosure"; |
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ID: aiam0472OpenMr. H. A. Sage, Director of Research and Engineering, Truck- Lite Company, P. O. Box 387, Jamestown, NY, 14701; Mr. H. A. Sage Director of Research and Engineering Truck- Lite Company P. O. Box 387 Jamestown NY 14701; Dear Mr. Sage: This is in reply to your letter of October 14, 1971, to Mr. Lewis Owe of this Office concerning an interpretation regarding your Truck-Lite No. 127 license plate light.; The requested interpretation concerns the 8 degree incident light angl specified in SAE J587, 'License Plate Lamps,' as follows:; >>>'When a single lamp is used to illuminate the plate, the lamp an license plate holder shall bear such relation to each other that at no point on the plate will the incident light make an angle of less than 8 deg to the plane of the plate.'<<<; Since the 8 degree incident light angle is also a requirement o Federal Motor Vehicle Safety Standard No. 108, all license plate lamp designs must conform to it. It is our position that the angle be measured from the optical center of the lens, therefore, the Electrical Testing Laboratories' position is valid. That is, the incident light angle of your lamp, without the paint shield and when mounted as it will be installed on the vehicle, is below the 8 degree minimum requirement.; Sincerely, E. T. Driver, Director, Office of Operating Systems, Moto Vehicle Programs; |
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ID: aiam0167OpenMr. W. D. Beamer, General Claim Agent, The Cleveland, Columbus, and Cincinnati Highway, Inc., 213 Euclid Avenue, Cleveland, OH 44114; Mr. W. D. Beamer General Claim Agent The Cleveland Columbus and Cincinnati Highway Inc. 213 Euclid Avenue Cleveland OH 44114; Dear Mr. Beamer: Your letter of June 17, 1969, to Mr. Donald Morrison of the Bureau o Motor Carrier Safety, concerning switching arrangements for running lamps, has been transferred to this Office for consideration and reply.; Enclosed for your information is a copy of Federal Motor Vehicle Safet Standard No. 108 on lighting requirements for motor vehicles. This standard is applicable to new vehicles manufactured on or after the effective date of January 1, 1969. Special wiring requirements, such as lamp switching arrangements, are included in paragraphs S3.4 through S3.4.7 of the standard.; We do not completely understand your usage of the term 'runnin lights.' If you are referring only to tail lamps, your attention is invited specifically to paragraph S3.4.3 of the standard which is quoted as follows: 'As a minimum the tail lamps shall be illuminated when the headlamps are illuminated except when the headlamps are being flashed.' The switching arrangements for other 'running lights,' such as clearance lamps and identification lamps, are at the option of the vehicle manufacturer.; Thank you for writing. Sincerely, Charles A. Baker, Office of Standards on Accident Avoidance Motor Vehicle Safety Performance Service; |
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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.