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: aiam2566OpenWilliam R. Scott, Esq., Messrs. Allen & Korkowski & Associates, P. O. Box 337, Rantoul, IL 61866; William R. Scott Esq. Messrs. Allen & Korkowski & Associates P. O. Box 337 Rantoul IL 61866; Dear Mr. Scott: This is in reply to your letter of March 3, 1977, to Mr. Oates of thi office asking whether your client, a manufacturer of motorcycle accessories, is subject to requirements imposed by 49 CFR Parts 573, 576, and 577 and 15 U.S.C. 1402.; For your reference I am enclosing a copy of a new Part 577 whic becomes effective June 28, 1977, that implements Part B of the National Traffic and Motor Vehicle Safety Act (15 U.S.C. 1411 *et seq*.) effective December 27, 1974. These new sections have superseded Section 1402, to which you referred. Since you apparently are unaware of these changes I am also enclosing a copy of the amended Act.; Because your client manufactures motor vehicle equipment other tha original equipment (*i.e*. accessories) its products appear to be 'replacement equipment' as defined by 15 U.S.C. 1419(2)(B). Since Parts 573 and 576 apply only to motor vehicle manufacturers and not to equipment manufacturers you are correct in your conclusion that these regulations are inapplicable to your client. We have proposed, however, that Part 573 be amended to apply to manufacturers of replacement equipment although no action has yet been taken on the proposal. I include a copy of that proposal.; You also asked about the applicability of Section 577.4 which you foun to be 'silent about the duty of manufacturers of motor vehicle equipment'. The Part 577 that you referenced reflects the statutory scheme that was in effect until December 27, 1974, under which a manufacturer of motor vehicle equipment (as contrasted with a vehicle manufacturer who also produced equipment) was not required to notify purchasers of safety-related defects or noncompliances which it, the manufacturer, had discovered. The equipment manufacturer's obligation to notify arose only upon determination of the existence of a safety-related defect or noncompliance by the NHTSA Administrator and in that event Section 577.5 requires the equipment manufacturer to follow the provisions of Section 577.4. The new statutory scheme of 15 U.S.C. 1411 *et seq*., as reflected in revised Section 577.5, now extends the notification and remedy obligation to safety-related defects and noncompliances discovered by manufacturers of replacement equipment.; Finally, you have asked if there is no duty to retain records how ca an equipment manufacturer 'observe the requirements of Part 577.4.' I assume what you mean is how can it notify 'the first purchaser (where known). . .and any subsequent purchaser to whom a warranty on such. . . item of equipment has been transferred'. The actual obligation of a manufacturer of replacement equipment today, however, is that established by 15 U.S.C. 1413(c)(3)(A), in effect since December 27, 1974, and it is to notify 'the most recent purchaser known to the manufacturer' (See also new Section 577.7(a)(2)(ii)(A). Congress appears to have recognized that manufacturers of small and less expensive items of motor vehicle equipment generally may not keep records of ultimate purchasers when it authorized our agency to issue a public notice when the public interest requires it (15 U.S.C. 1413(c)(3)(B)). Since there is no obligation for a manufacturer to know the names of its purchasers, NHTSA will accept in good faith an equipment manufacturer's statement as to the extent of its knowledge of its most recent purchasers. Under proposed Section 573.7(c) your client, as a manufacturer of motor vehicle equipment, would be required to maintain certain records including a list of the names and addresses of the 'most recent purchasers known to the manufacturer'. Such a list would probably at a minimum comprise distributors of the product, might also include the dealers of the distributors, and possibly in some instances the ultimate purchaser. But it is not a requirement that steps be taken to know and list the names and addresses of all ultimate purchasers.; If you have further questions after reviewing this letter and it enclosures I will be happy to answer them for you.; Yours truly, Frank Berndt, Acting Chief Counsel |
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ID: aiam5309OpenLawrence P. White, Acting Director Bureau of Motor Vehicles Department of Transportation Commonwealth of Pennsylvania Harrisburg, PA 17122; Lawrence P. White Acting Director Bureau of Motor Vehicles Department of Transportation Commonwealth of Pennsylvania Harrisburg PA 17122; "Dear Mr. White: This responds to your letter of December 13, 1993 asking several questions concerning a recent amendment to Standard No. 217, Bus Emergency Exits and Window Retention and Release (57 FR 49413, November 2, 1992). Your questions and the response to each follows. 1. The effective date - is it the chassis manufacturer's date of completion, the final stage manufacturer's date of completion, or somewhere in between? The effective date for the November 2 final rule is May 2, 1994. Only vehicles manufactured on or after the effective date of an applicable requirement in a Federal motor vehicle safety standard must comply with that requirement. If a vehicle is manufactured in two or more stages, the final stage manufacturer is required to certify that the vehicle complies with 'the standards in effect on the date of manufacture of the incomplete vehicle, the date of final completion, or a date between those two dates.' (49 CFR Part 568.6). 2. Based on the formula for emergency exit space, is the area of the front service door to be included? Does this mean on a vehicle of 60 to 77 passengers, the only additional requirements beyond the front and rear doors is a left side exit door? The November 2 final rule requires additional emergency exit area (AEEA) for some buses. The amount, if any, of AEEA which must be provided is determined by subtracting the area of the front service door and either the area of the rear emergency door or the area of the side emergency door and the rear push- out window, depending on the configuration of the bus (S5.2.3.1). These are the minimum exits required on all buses. If AEEA is required, the first additional exit which must be installed is a left side emergency door (for a bus with a rear emergency door) or a right side emergency door (for a bus with a left side emergency door and a rear push-out window). The number of exits may vary for buses which carry the same number of passengers, because the amount of area credited for each exit is the area of daylight opening, and because different variations of types of exits are possible. However, in the regulatory evaluation for the final rule, the agency estimated that a bus would not be required to have a roof exit (the second type of additional exit required) unless the capacity was greater than 62 (for a bus with a rear emergency door) or 77 (for a bus with a left side emergency door and a rear push-out window). 3. The 'clear aisle space' required for exit to the proposed side emergency door, according to federal specifications, can be met with a flip-up type seat or a clear opening of 12', as measured from the back of the door forward. Are there any specifications, definitions, or descriptions provided as to what would be considered a 'flip seat'? The November 2 final rule allowed a flip-up seat to be adjacent to a side emergency exit door 'if the seat bottom pivots and automatically assumes and retains a vertical position when not in use, so that no portion of the seat bottom is within' the required 12 inch aisle to the exit (S5.4.2.1(a)(2)(ii)). The agency did not otherwise define a flip-up seat, nor did it include any performance requirements for these seats. 4. Also, there is concern regarding school buses that are equipped with the 'flip seat' by the emergency door opening and the possibility of school children, either intentionally or accidently, unlatching the door latch mechanism. Are the door latch mechanisms to be equipped to help prevent this from occurring? Standard No. 217 includes requirements for the type of motion and force required to release an emergency exit (S5.3.3). One of these requirements is that the motion to release a door must be upward from inside the bus (upward or pull-type for school buses with a gross vehicle weight rating of 4,536 kilograms or less). This is intended to lessen the chance of a door accidently being opened, without unnecessarily making the exit more complicated to open in an emergency. In addition, warning alarms are required for door and window exits to notify the driver that the exit has been opened. I hope you find this information helpful. If you have any other questions, please contact Walter Myers of my staff at this address or by phone at (202) 366-2992. Sincerely, John Womack Acting Chief Counsel"; |
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ID: aiam2136OpenMr. W. G. Milby, Staff Engineer, Blue Bird Body Company, P.O. Box 937, Fort Valley, GA 31030; Mr. W. G. Milby Staff Engineer Blue Bird Body Company P.O. Box 937 Fort Valley GA 31030; Dear Mr. Milby: This responds to Blue Bird Body Company's October 16, 1975, questio whether Standard No. 121, *Air Brake Systems*, preempts a State requirement that air-braked school buses be equipped with an audible and visual antilock failure warning signal and an air pressure gauge with a 3-inch display.; Standard No. 121 requires that trucks and buses be equipped with an ai pressure gauge, but it does not specify the size of the display (S5.1.4). Section S5.1.6 of the standard requires that trucks and buses be equipped with an antilock failure warning signal that is either visible within the driver's forward field of view, or both audible and continuously visible if it is not within the driver's forward field of view.; Section 103(d) of the National Traffic and Motor Vehicle Safety Act o 1966 (15 U.S.C. 1392(d)) provides that no State or political subdivision of a State may promulgate or continue in effect standards applicable to an aspect of motor vehicle or motor vehicle equipment performance which is covered by a Federal motor vehicle safety standard, unless the standards are identical.; The Federal requirements must be regarded as conclusive with regard t aspects of air brake performance covered by Standard No. 121 in order to maintain the uniformity necessary in a Federal regulatory scheme. This was affirmed in a recent decision rendered in a case brought by the Motorcycle Industry Council, Inc. against the State of California in the United States District Court for the Eastern District of California concerning the preemption of a California State requirement that motorcycle headlamps be wired to operate when the engine is running. The Court held that the California requirement is preempted by the Federal Motor Vehicle Safety Standard No. 108 since the NHTSA intended to cover all aspects of performance directly involving motorcycle headlamps.; The requirements described in your letter would be preempted b Standard 121 since the aspects of performance that would be affected are covered by the Federal standard.; You should note that this discussion of State 'requirements' onl refers to rules of general applicability within a State or municipality. It does not refer to purchase specifications that may be imposed by any person or organization, including a State or municipality, with respect to vehicles purchased for the person or organization's own use. Such specifications are not limited by Federal law, and in the case of governmental bodies are specifically allowed by S103(d), although of course they cannot alter a manufacturer's duty to conform to Federal standards.; Sincerely, Frank Berndt, Acting Chief Counsel |
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ID: aiam2423OpenMr. M. P. McNiff, Global Market Planning Manager, Solar Control Products, 3 M Company, 3 M Center, Saint Paul, MN 55101; Mr. M. P. McNiff Global Market Planning Manager Solar Control Products 3 M Company 3 M Center Saint Paul MN 55101; Dear Mr. McNiff: This is in response to your September 22, 1976, letter regarding th use of 'Solar Control Reflective Films' in motor vehicles. You asked several questions concerning the applicability of Federal requirements to the manufacture and sale of your 'Scotchtint' protective film.; I am enclosing a copy of a letter to Mr. Mark T. Lerche from thi agency that discussed the applicability of Federal requirements to his company's 'Madico' solar protective film. The discussion in that letter is equally applicable to 'Scotchtint' protective film and should answer your questions. The main point to be noted is that these protective films that are attached to glass are not 'glazing' themselves and, therefore, the requirements of Federal Safety Standard No. 205 are not applicable to the manufacture of the film. It is the responsibility of the manufacturer, dealer, or vehicle repair business that applies the film to ensure that glazing remains in compliance with the standard. Of course, if your company applies the film to any glazing you would fall in this same category.; It is laudable that your company is interested in ensuring that it film is not used in a manner that would be detrimental to the safety of the motoring public. Although it is not your responsibility to do so, a safety warning to your consumers that 'Scotchtint' should not be placed on vehicle glazing in 'areas requisite for driving visibility,' would be helpful.; We appreciate your interest in motor vehicle safety. Sincerely, Frank Berndt, Acting Chief Counsel |
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ID: aiam2073OpenMr. Naoyoshi Suzuki, Nissan Motor Co., Ltd. 560 Sylvan Avenue, Englewood Cliffs, NJ 07632; Mr. Naoyoshi Suzuki Nissan Motor Co. Ltd. 560 Sylvan Avenue Englewood Cliffs NJ 07632; Dear Mr. Suzuki:#This is in response to your September 16, 1975, lette to Mr. John Carson of this agency, concerning Federal Motor Vehicle Safety Standard No. 101, *Control Location, Identification and Illumination*. You requested an interpretation of the footnote to Table 1 of the standard which reads: 'Framed areas may be filled'.#The National Highway Traffic Safety Administration interprets this footnote as permitting the vehicle manufacturer the option of depicting the interior of a symbol to which it applies with the same color as the boundary of the symbol, as an alternative to depicting the interior with the same color as the background. In the hazard warning signal symbol, which consists of a triangle containing a smaller triangle, only the area between the triangles is part of the interior. The center of the small triangle is part of the background. Therefore, only the first and third of the samples submitted with your letter are permitted. For your convenience, I have enclosed a copy of the samples indicating which ones are permitted.#Sincerely, Frank A. Berndt, Acting Chief Counsel; |
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ID: aiam2589OpenMr. Don W. Vierimaa, Engineering Manager, TTMA, 2430 Pennsylvania Avenue, N.W., Washington, D.C. 20037; Mr. Don W. Vierimaa Engineering Manager TTMA 2430 Pennsylvania Avenue N.W. Washington D.C. 20037; Dear Mr. Vierimaa: This responds to your March 16, 1977, letter in which you ask for a interpretation of the certification label requirements of Standard No. 120, *Tire Selection and Rims for Motor Vehicles Other Than Passenger Cars*, as they apply to trailers.; In your first question, you ask whether a trailer manufacturer ma conform with the certification requirements in any one of three ways: list the GVWR and GAWR with the corresponding tires, rims, and inflation pressure with which the trailer is equipped, list all suitable combinations with the required information as shown in the example appearing in Standard No. 120, or list only the maximum GVWR and maximum GAWR with the proper tires, rims, and inflation pressure, plus the GVWR and GAWR of the trailer with the tires, rims, and inflation pressure with which it is equipped.According to the requirements of Standard No. 120, any of the three methods outlined above would appear to be acceptable. Your second question presents a sample certification plate which lists all of the axles on the trailer. You ask whether it is permissible, where the data for all axles is identical, to list the proper tires, rims, and inflation pressure for the front axle then merely state 'Same as Front' for the remaining axles rather than repeat the same data for all axles. The label requirements of the standard do not permit the approach you suggest. You must list all data for each axle. You should note that there is a proposal to amend Part 567, *Certification*, to permit a simplification of label requirements when the data for all axles is identical. I am enclosing a copy of this proposal for your information.; Sincerely, Joseph J. Levin, Jr., Chief Counsel |
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ID: aiam3232OpenMr. Carl G. F. Pedersen, Aveco Trucks of North America, Inc., P.O. Box 1102, Blue Bell, PA 19422; Mr. Carl G. F. Pedersen Aveco Trucks of North America Inc. P.O. Box 1102 Blue Bell PA 19422; Dear Mr. Pedersen:#This is in response to your request for a interpretation of Federal Motor Vehicle Safety Standard 101-80, *Controls and Displays*. You described a bulb check button which could be activated at any time by merely pushing it in, but which when released would be automatically deactivated. You asked whether the possible activation of this button at any time would take it out of compliance with section 5.3.1 of Safety Standard 101-80.#This section states that 'a telltale shall not emit light except...during a bulb check upon vehicle starting.' This provision was intended to prevent the driver from accidently (sic) leaving the bulb check control activated and thereby creating a situation where a defective functioning of the vehicle would go unnoticed by the driver. Since the bulb check control that you described cannot accidently (sic) be left in the on position since it is deactivated when the driver releases it, section 5.3.1 of Safety Standard 101-80 would not operate so as to prohibit use of this device.#I hope that you have not been inconvenienced by our delay in sending you this response.#Sincerely, Frank Berndt, Chief Counsel; |
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ID: aiam2970OpenMr. James Tydings, Thomas Built Buses, Inc., 1408 Courtesy Road, P.O. Box 2450, High Point, NC 27261; Mr. James Tydings Thomas Built Buses Inc. 1408 Courtesy Road P.O. Box 2450 High Point NC 27261; Dear Mr. Tydings: This responds to your February 28, 1979, letter asking about th remanufacturing of vehicles using old chassis and new bodies. In particular, you ask whether these vehicles must comply with the new safety standards.; The remanufacturing operation that you mention need not comply with th new safety standards. Such a remanufactured vehicle may need to comply with the safety standards in effect on the date of manufacture of the used chassis. Otherwise, there might be a rendering inoperative of the compliance of the vehicle with the safety standards. I am enclosing a copy of an interpretation that discusses the remanufacturing issue.; Sincerely, Frank Berndt, Acting Chief Counsel |
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ID: aiam3662OpenMr. John C. Dobbs, Project Manager, E-Z-Go Textron, P.O. Box 388, Augusta, GA 30913-2699; Mr. John C. Dobbs Project Manager E-Z-Go Textron P.O. Box 388 Augusta GA 30913-2699; Dear Mr. Dobbs: This is in reply to your letter of February 4, 1983, telling of you wish to build a four-wheeled light weight traffic enforcement vehicle similar to a three-wheeled machine manufactured by Cushman. You have asked whether you have to meet passenger car safety standards 'or can we obtain a waiver for this vehicle only to comply with motorcycle safety standards?' You have enclosed a brochure on the vehicle you propose to modify, Textron's GX-800.; I am sorry to say that only vehicles with three wheels or less ar defined as 'motorcycles' for purposes of compliance with the Federal motor vehicle safety standards. Years ago, the agency totally excluded from the application of those standards four-wheeled vehicles with a curb weight of 1000 pounds or less such as the GX-800. However, that exclusion was terminated in the early 1970's.; A manufacturer of 10,000 vehicles or less per year may petition for temporary exemption from any safety standard where immediate compliance would cause substantial economic hardship. However, he must make a good faith effort to bring the vehicle into compliance during the exemption period. Although this would appear impossible with your vehicle because of its physical limitations, the agency has in the past exempted replicas of 1900-style vehicles where full compliance was manifestly not feasible. I enclose a copy of Title 49 Code of Federal Regulations Part 555 which sets out the exemption procedures. If your planned vehicle would have a cargo box, similar to the one on the Cushman vehicle, your vehicle could be considered a 'truck' for compliance purposes.; As a car or truck, your vehicle would also have to comply with Federa fuel economy and emissions standards. Exemptions from fuel economy standards may be sought under 49 CFR Part 525. As to the emissions standards, you should write the Environmental Protection Agency.; Sincerely, Frank Berndt, Chief Counsel |
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ID: aiam3398OpenMr. Seymour S. Weinblatt, Weinblatt & Knee, Counsellors at Law, Five Main Street, P.O. Box 985, Flemington, NJ 08822; Mr. Seymour S. Weinblatt Weinblatt & Knee Counsellors at Law Five Main Street P.O. Box 985 Flemington NJ 08822; Dear Mr. Weinblatt: This responds to your letter of March 5, 1981, in which you requested copy of Federal Motor Vehicle Safety Standard No. 205, *Glazing Materials*. You are apparently trying to determine what types of glazing material may be used in 'caps' installed on truck bodies.; Safety Standard No. 205 specifies performance requirements for glazin materials to be used in motor vehicles and motor vehicle equipment. The standard incorporates by reference the American National Standard 'Safety Code for Safety Glazing Materials for Glazing Motor Vehicles Operating on Land Highways,' Z26.1-1966 (ANSZ26). Copies of both standards are enclosed. ANS Z26 and Standard No. 205 list 13 'Items' or types of glazing that vary in terms of performance tests each item must pass and the locations in which each type of glazing may be used. While the meaning of the word 'cap' as used in your letter is somewhat unclear, we presume you are referring to a 'pickup cover.' A 'pickup cover' is defined in paragraph S4 of Standard No. 205 as a camper having a roof and sides but without a floor, designed to be mounted on and removable from the cargo area of a truck by the user. All 13 items of glazing may be used in pickup covers. However, some items (e.g., Item 6) may not be used in forward-facing windows, and others (e.g., Item 5) may not be used at levels requisite for driving visibility.; Certification and marking requirements for glazing are found i paragraphs S6.4 and S6.5 of Standard No. 205.; We hope you find this information helpful. Please contact this offic if you have any further questions.; Sincerely, Frank Berndt, 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.