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: aiam5264OpenMr. Larry Grabsky VML and Colonna Corp. 2122 - 65th St. Brooklyn, NY 11204; Mr. Larry Grabsky VML and Colonna Corp. 2122 - 65th St. Brooklyn NY 11204; Dear Mr. Grabasky: This is reply to your recent letter asking our view on the use of decorative neon lamps, or of oscillating or revolving ones. This agency establishes the Federal motor vehicle safety standards which must be met from the time a motor vehicle is manufactured up until its sale to its first purchaser for purposes other than resale. The new car dealer is responsible for ensuring that any lighting equipment that it adds before the sale of the vehicle does not impair the effectiveness of lighting equipment that is required by the standard. The determination of whether an impairment exists is made by the person responsible for adding the equipment. If this determination appears clearly erroneous, NHTSA will question it. In addition, all lighting equipment added before the vehicle's first sale must be steady burning when it is used. If the lighting equipment is added after the vehicle's sale by a manufacturer, dealer, distributor, or motor vehicle repair business, it is subject to the restriction that it not 'render inoperative, in whole or in part' any lamp that has been installed in accordance with Standard No. 108. Supplementary motor vehicle lighting equipment, whether added before or after initial sale of the vehicle, is subject to the laws of States in which the vehicle is operated, even if the equipment is not prohibited under Federal law. With respect to neon lights, we are aware of aftermarket installations on the underside of vehicles that illuminate the pavement below. If such lamps create glare that distracts another motorist from perceiving, for example, the turn signals in use, we would consider that an impairment and a partially rendering inoperative within the meaning of those terms. We are unable to advise you on State laws regarding the use of neon lights on vehicles, and suggest that you write for an opinion to the American Association of Motor Vehicle Administrators, 4600 Wilson Boulevard, Arlington, Va. 22203. We are unsure what you mean by 'oscillating' but Standard No. 108, in general, requires lamps added before a vehicle's initial sale to be steady burning in use, unless otherwise permitted (such as turn signals and hazard warning signals, and automatic flashing of headlamps for signalling purposes). Installation of a non steady burning lamp by a manufacturer, dealer, distributor, or motor vehicle repair business after initial sale could be viewed as a rendering inoperative depending upon the circumstances. Standard No. 108 does allow a motorcycle to be equipped with a modulating headlamp for daytime use. The modulation permitted is 240 +/- 40 cycles per minute. When NHTSA proposed to allow the modulating headlamp, some commenters were concerned that the flashing might trigger a photic reaction akin to an attack of epilepsy, in onlookers. We believe that the reaction is most likely to occur at a frequency of 10 hz against a very dark background. Thus, care should be taken in the use of supplementary lamps that are not steady burning. As for revolving lamps, we believe that these are generally found on police and emergency vehicles such as ambulances and tow trucks. Whether it is permissible to equip a vehicle with these lamps and to use them is a question to be answered under State law. Sincerely, John Womack Acting Chief Counsel; |
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ID: aiam0436OpenMr. K. Shindo,Executive Director,Meiji Rubber & Chemical Company, Ltd.,Kojima Building,10-2, Nishishinjuku, 1Chome.Shinjuku-Ku,Tokyo, Japan; Mr. K. Shindo Executive Director Meiji Rubber & Chemical Company Ltd. Kojima Building 10-2 Nishishinjuku 1Chome.Shinjuku-Ku Tokyo Japan; Dear Mr. Shindo:#This is in reply to your letter of September 3 askin questions about compliance of hydraulic brake hose assemblies with Federal Motor Vehicle Safety Standard No. 106.#With respect to your first to questions, The National Highway Traffic Safety Administration does not require that you demonstrate compliance with Standard No. 106 prior to supplying Japanese car manufacturers with brake hose assemblies to be installed on cars intended for export to the united States. If the Japanese vehicle manufacturers request proof of compliance from you (apparently in the form of a certification from the Commonwealth of Pennsylvania based upon test reports from only one or two test laboratories) such a request os solely a business matter between you and the vehicle manufacturer.#Your third question points out that proposed Standard No. 106 (Docket No. 1-5, Notice 7) would eliminate the specification of brake material for hydraulic brake hoses and asks whether you may implement this 'revision' at the present time. Notice 7 is a proposal only, and the current requirements specifying braid material remain in effect until a formal amendment of Standard No. 106 occurs. The brake hose manufacturer's code number, the subject of your fourth question is also a proposal which may or may not be adopted in the final rule.#Sincerely,Lawrence R. Schneider,Acting Chief Counsel; |
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ID: aiam5634OpenMr. Ben Ray Route 2, Box 229-E Savannah, TN 38372; Mr. Ben Ray Route 2 Box 229-E Savannah TN 38372; "Dear Mr. Ray: This responds to your letter asking about Federa requirements for automatic brake adjusters on log trailers. According to your letter, you manufacture log trailers, using used axles that already have what you call 'regular' (i.e., manual) brake adjusters on them. In an October 13, 1995 telephone conversation with Mr. Marvin Shaw of my staff, you further stated that the wheels, brakes, and suspension are typically used, but that occasionally you use new brake systems. You also clarified that these trailers are used on the public roads as well as in the woods for transporting logs to the mills. You asked whether it is permissible to use manual brake adjusters instead of automatic adjusters. The answer depends on whether your log trailers are equipped with new or used components and the trailer continues to use the Vehicle Identification Number (VIN) and to be owned by the user of the reassembled vehicle. By way of background information, the National Highway Traffic Safety Administration (NHTSA) issues safety standards for new motor vehicles and new motor vehicle equipment. The agency does not provide approvals of motor vehicles or motor vehicle equipment. Instead, manufacturers are required to certify that their vehicles or equipment meet all applicable standards. One such standard is Standard No. 121, Air brake system, which requires new trailers to be equipped with automatic brake adjusters. The following represents our opinion based on the facts provided in your letter. NHTSA's regulations specifically address the question of when trailers produced by combining new components and used materials are considered to be new trailers. Section 49 CFR 571.7(f) states that when new and used components are used in trailer manufacture, the trailer will be considered 'newly manufactured' unless each of the following three conditions is true with respect to the trailer. First, the trailer running gear assembly, which includes the axle(s), wheels, braking and suspension, is not new and was taken from an existing trailer. Second, the existing trailer's identity is continued in the reassembled vehicle with respect to the VIN. Third, the existing trailer is owned or leased by the user of the reassembled vehicle. In other words, a log trailer will generally be considered newly manufactured, unless all these conditions are met. If a trailer is considered newly manufactured, then it must comply with the current requirements applicable to trailers. Among other things, this means that the trailer must be equipped with automatic adjusters. If a trailer meets these three conditions, then it is considered not newly manufactured and may be equipped with manual adjusters. I hope this information is helpful. If you have any questions about NHTSA's safety standards, please feel free to contact Marvin Shaw at this address or by telephone at (202) 366-2992. Sincerely, Samuel J. Dubbin Chief Counsel"; |
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ID: aiam4926OpenJohn C. Buonora Director The City of New York Police Department Motor Transport Division 53-15 58th Street Woodside, NY 11377; John C. Buonora Director The City of New York Police Department Motor Transport Division 53-15 58th Street Woodside NY 11377; "Dear Mr. Buonora: This responds to your letter of November 1, 1991 'regarding the removal of the operating handle for the reclining mechanism of the 1991 Chevrolet police car split bench seat.' You asked for 'a written determination stating whether or not the removal of the operating handle violates the seat safety standard and any possible NYPD legal liability in the event of an accident.' I am pleased to have this opportunity to explain the requirements of Federal law for you. The National Traffic and Motor Vehicle Safety Act (Safety Act) authorizes this agency to issue safety standards for new motor vehicles and new items of motor vehicle equipment. The Safety Act requires manufacturers to certify that each of their new vehicles or new items of equipment complies with all applicable safety standards at the time the product is delivered to the first purchaser in good faith for purposes other than resale. After a vehicle is delivered to the first purchaser for purposes other than resale, modifications to the vehicle are affected by section 108(a)(2)(A) of the Safety Act (15 U.S.C. 1397(a)(2)(A)). That section prohibits any manufacturer, dealer, distributor, or repair business from 'rendering inoperative' any device or element of design installed in a vehicle in compliance with a safety standard. Therefore, if a business in any of the aforementioned categories removed the reclining mechanism operating handle, it would need to ensure that the vehicle continued to comply with all applicable safety standards following the removal. Please note that section 108(a)(2)(A) does not affect modifications made by vehicle owners to their own vehicles. Therefore, the City of New York Police Department may itself remove the operating handle for the seat reclining mechanism on vehicles it owns without violating the 'render inoperative' provision or any other provisions of the Safety Act, even if such removal did result in the vehicle no longer complying with all applicable safety standards. However, the individual States have the authority to regulate the modifications that owners can make to their own vehicles. You should contact the State of New York to learn if it has enacted any laws or regulations that apply to your planned modification. In addition, since legal liability is a matter of state law, you may wish to consult with an attorney familiar with the law in the State of New York regarding potential liability. I hope you find this information helpful. If you have further questions, please contact Mary Versailles of my staff at this address or by telephone at (202) 366-2992. Sincerely, Paul Jackson Rice Chief Counsel"; |
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ID: aiam2364OpenMr. Jack A. Johnson, Chief Engineer, MOTAC Inc., 8400 East Slauson Ave., Pico Rivera, CA 90660; Mr. Jack A. Johnson Chief Engineer MOTAC Inc. 8400 East Slauson Ave. Pico Rivera CA 90660; Dear Mr. Johnson: This responds to Motac's June 24, 1976, request to know why a traile with a flat cargo-carrying surface that is not more than 40 inches above the ground is considered a 'heavy hauler trailer' (as defined in Standard No. 121, *Air Brake Systems*), while a trailer with an inclined cargo-carrying surface that is more than 40 inches above the ground over the fifth wheel attachment point is not considered a heavy hauler trailer. You also request confirmation that the period for exclusion of heavy hauler trailers from the standard has been extended to September 1, 1977.; At the time that the 'heavy hauler trailer' exclusion was implemented the agency considered and rejected the addition of trailers with inclined beds to the excluded category. I have enclosed a copy of the notice that implemented the exclusion, which states 'The NHTSA has concluded that trailers with beds higher than 40 inches (including trailers whose beds are below 40 inches over the wheels but higher than 40 inches over the fifth wheel) can accommodate the new larger brake packages available at this time.' Of course, the exclusion was intended to and does apply to the traditional trailer with a gooseneck and a flat cargo-carrying surface that is not more than 40 inches above the ground. The 'double-drop semi', the 'stock drop frame flat-bed', and the '40 '-0' single axle drop frame platform semi' you describe appear to qualify as heavy hauler trailers.; I have enclosed a copy of the amendment of Standard No. 121 tha extends the date for exclusion of heavy hauler trailers to September 1, 1977.; Yours truly, Frank Berndt, Acting Chief Counsel |
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ID: aiam0359OpenMr. Sidney W. Smith, Director of Engineering, Williamsen Body & Equipment Company, 1925 Indiana Avenue, P.O. Box 1076, Salt Lake City, UT 84111; Mr. Sidney W. Smith Director of Engineering Williamsen Body & Equipment Company 1925 Indiana Avenue P.O. Box 1076 Salt Lake City UT 84111; Dear Mr. Smith: This is in reply to your letter of May 18, 1971, requesting a interpretation of the Tire Identification and Record Keeping Regulation (49 C.F.R. Part 574) as it applies to vehicles manufactured in two or more stages.; The final-stage manufacturer, as a vehicle manufacturer, under sectio 113(f) of the National Traffic and Motor Vehicle Safety Act, is required to keep a record of the name and address of the first purchaser for purposes other than resale, and to maintain a record of the tires shipped on or in the completed vehicle (49 C.F.R. 574.10). Although the final-stage manufacturer may designate someone to maintain the records required under section 574.10 of the Tire Identification and Record Keeping Regulation, the legal responsibility for maintaining the records remains with the final-stage manufacturer.; However, the incomplete vehicle manufacturer, or any intermediat manufacturer, may assume 'legal responsibility for all duties and liabilities imposed on manufacturers by (the Act) with respect to the vehicle as finally manufactured . . .' (49 C.F.R. 568.7). In such a case, the responsibilities for maintaining the records required by the Act and by the Tire Identification and Record Keeping Regulation will be assumed by the incomplete vehicle manufacturer, or any intermediate manufacturer, and the final-stage manufacturer will be relieved of all liability for maintaining the records.; Under the Tire Identification and Record Keeping Regulation, th manufacturer is not required to keep a record of tires manufactured before May 22, 1971, but sold after that date. However, where feasible, we recommend that the manufacturer maintain some system whereby he can identify the type of tire on vehicles he sells as well as the purchaser of the vehicle.; For your convenience, we have enclosed copies of the Act with it amendments, the Tire Identification and Record Keeping Regulation, and the Certification Regulation.; Sincerely, Lawrence R. Schneider, Acting Chief Counsel |
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ID: aiam2734OpenMr. W. G. Milby, Manager, Engineering Services, Blue Bird Body Company, P. O. Box 937, Fort Valley, GA 31030; Mr. W. G. Milby Manager Engineering Services Blue Bird Body Company P. O. Box 937 Fort Valley GA 31030; Dear Mr. Milby: This responds to your October 24, 1977, letter asking whether th framework of a roof hatch must comply with the requirements of Standard No. 221, *School Bus Body Joint Strength*.; The terms which establish the applicability of the requirements of th standard to a particular section of school bus body are defined in S4 of the standard. Read together they establish the following test. If the edge of a surface component (made of homogeneous material) that encloses occupant space in a bus comes into contact or close proximity with any other body component, the requirements of S5 apply, unless the area in question is designed for ventilation or another functional purpose, or is a door, window, or maintenance access panel. Applying this test to the frame of a roof hatch, it appears that this joint need not comply with the requirements. This conclusion is reached because the National Highway Traffic Safety Administration concludes that a roof hatch is equivalent to a door or window for the purposes of the application of the requirements. The joint connecting the frame of a door, window, or roof hatch to a bus body falls within the exception to the applicability of Standard No. 221.; Sincerely, Joseph J. Levin, Jr., Chief Counsel |
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ID: aiam0709OpenMr. James A. Walsh, President, Armstrong Rubber Company, 500 Sargent Drive, New Haven, Connecticut 06507; Mr. James A. Walsh President Armstrong Rubber Company 500 Sargent Drive New Haven Connecticut 06507; Dear Mr. Walsh: #We are in receipt of your response of October 7, 1971 to CIR 368.1.1, concerning Admiral Belted 78 tires that were branded on one side only. #The Administration considers the act of branding on only one sidewall at a time when the standard required both sidewalls be labeled, to be inexcusable. If similar incidents of overlooking requirements come to our attention we will pursue civil penalties. However, based on the information before us we are closing our files in this case with regard to both civil penalties and defect notification. The Administration reserves the right to reopen this file in the event that further violations of this nature come to its attention. #Sincerely, Francis Armstrong, Director, Office of Standards Enforcement, Motor Vehicle Programs; |
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ID: aiam3826OpenMr. Fred J. Clark, Vintage Cars & Restoration Center, 560 N.E. F Street, Grants Pass, OR 97526; Mr. Fred J. Clark Vintage Cars & Restoration Center 560 N.E. F Street Grants Pass OR 97526; Dear Mr. Clark: This is in response to your letter of March 5, 1984 in which yo request the opinion of the National Highway Traffic Safety Administration (NHTSA) regarding whether you are permitted, under the Federal Odometer law (Title IV of the Motor Vehicle and Cost Savings Act, 15 U.S.C. S1981, *et seq*.), to turn the odometers, on the restored vintage automobiles which you sell, back to zero. It is the opinion of this agency that you may not.; Section 404 of the Act, 15 U.S.C. S1984, makes it unlawful for an person to 'disconnect, reset, or alter or cause to be disconnected, reset, or altered, the odometer of any motor vehicle with intent to change the number of miles indicated thereon.' The term odometer means an instrument for measuring and recording the actual distance a motor vehicle travels while in operation. Although each motor vehicle which you sell has been restored and although each may be, as you claim, 'better than it was as a new car', the odometers must continue to reflect the actual miles which these vehicles have travelled.; The Federal odometer law also requires that a written disclosure of th mileage registered on the odometer by provided by the seller of a motor vehicle to the purchaser at the time ownership of the vehicle is transferred. If the odometer mileage is incorrect, the Act requires that the purchaser be furnished with a written statement to that effect. 15 U.S.C. 1988, 49 C.F.R. S580.4. All dealers and distributors of motor vehicles are required to retain a copy of each odometer disclosure statement which they issue or receive. These statements are to be retained for four years at their principal place of business. 49 C.F.R. S580.7.; NHTSA found, however, that the value of antique vehicles is determine not by the number of miles travelled by such vehicles, but rather by their age, condition and scarcity. The Agency therefore exempted from the odometer disclosure requirements of section 580.4, vehicles which are 25 years old or older. 49 C.F.R. S580.5(a)(3). NHTSA also exempted from these requirements, vehicles having a gross vehicle weight rating (GVW) of more than 16,000 pounds, S580.5(a)(1), and vehicles which are not self- propelled, S580.5(a)(2). Please note that these are exemptions from the odometer disclosure requirements only. They do not permit tampering with the odometer.; Before you decide whether or not to issue odometer disclosur statements for the 25 years old and older vehicles which you sell, however, you should consider that at least two Federal District Courts have declared the exemptions to be void. The courts found that NHTSA had exceeded its authority in fashioning exemptions to the odometer disclosure requirements. *Lair v. Lewis Service Center*, 428 F.Supp. 778 (D.Neb. 1977), *Davis v. Dils Motor Company*, 566 F.Supp. 1360 (S.D.W.Va. 1983). These cases did not address the validity of the exemption of 25 year old and older vehicles. They addressed instead the validity of the exemption of vehicles having a GVW of more than 16,000 pounds. Their finding, however, that the Agency lacked authority to create the exemptions, may equally apply to this case.; Their findings are not binding on other courts, and the Agenc continues too believe that the exemptions it created are valid. It is important that you consider these decisions, however, since another court could find them well-reasoned or persuasive, and follow the findings that they reached.; If you have additional questions regarding the requirements of th Federal odometer law, please call Heidi Lewis Coleman of my staff at (202) 426-2992 or write to her attention.; Sincerely, Frank Berndt, Chief Counsel |
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ID: aiam1548OpenLee and Winnie Jones, District Directors, National Campers & Hikers Assoc., Virginia Avenue, Sturgis, Michigan 490091; Lee and Winnie Jones District Directors National Campers & Hikers Assoc. Virginia Avenue Sturgis Michigan 490091; Dear Lee and Winnie Jones: This is in response to your letter of June 27, 1974, objecting to th use of extension mirrors on automobiles when a trailer is not in tow.; Although we fully appreciate the possible dangers inherent in the us of extension mirrors, this agency has no authority to regulate the use of such equipment. The authority that Congress has conferred upon the National Highway Traffic Safety Administration relates to the safe manufacture of motor vehicles and motor vehicle equipment, and not directly to its use. Therefore. unless some showing can be made that the design of the mirrors is dangerous, we have no authority to deal with the problem you describe.; Yours truly, Richard B. Dyson, Assistant 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.