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: aiam2726OpenMr. Michael Flowers, Manager, Electric Products Division, General Engines Company, 591 Montana Boulevard, Jewell, N.J. 08080; Mr. Michael Flowers Manager Electric Products Division General Engines Company 591 Montana Boulevard Jewell N.J. 08080; Dear Mr. Flowers: This is in reply to your letter of November 4, 1977, asking for a interpretation of Federal Motor Vehicles Safety Standard No. 123 *Motorcycle Controls and Displays* as it applies to electricity-powered motor driven cycles that you manufacture.; "Paragraph S5.1 of Standard No. 123 requires each motorcycle to b equipped with a supplemental engine stop control. Your Electroped GX 2000 is operated through a 'uni-control lever' which, when released, turns off the power j source 'thereby acting as an automatic motor stop in the event of an accident.' Your Electroscooter is operated through a twist-grip throttle and when it is released 'the motor is completely off.' You have asked how S5.1 applies to your vehicles."; In our opinion, Standard No. 123 was not drafted wit electricity-powered motorcycles in mind. Unlike a motorcycle powered by an internal combustion engine, the driving force (i.e. current) of an electricity-powered motorcycle is terminated when the force control is released, and no supplemental engine stop control or 'emergency kill button' is required. In other words, S5.1 does not appear to be an appropriate requirements for an electricity-powered vehicle.; however, until Standard 123 can be amended appropriately your vehicle are required to be equipped with the supplemental engine stop control. In other instances where manufacturers have found conflicts between the safety standards and electricity-powered vehicles they have applied for a temporary exemption from such standards.; Work is in progress on your request to be exempted from Standard No 120, and by including your letter and this interpretation to it in the docket, we can include in the *Federal Register* notice a request to be exempted from S5.1 as well. Please confirm that this is acceptable to you.; Sincerely, Joseph J. Levin, Jr., Chief Counsel |
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ID: aiam2876OpenMr. Ken Yoneyama, Chief Engineer, Bridgestone Research Inc., 350 Fifth Ave., Suite 4202, New York, NY 10001; Mr. Ken Yoneyama Chief Engineer Bridgestone Research Inc. 350 Fifth Ave. Suite 4202 New York NY 10001; Dear Mr. Yoneyama: This is in response to your letter of September 22, 1978, askin whether tires listed in Table 1-A of Appendix A, Federal Motor Vehicle Safety Standard No. 109, *New Pneumatic Tires - Passenger Cars*, must comply with Part 575.104, *Uniform Tire Quality Grading Standards*, (UTQGS), if the tires are installed as original equipment on multi-purpose passenger vehicles. You also inquire as to the effective dates for the provision of UTQGS information to first purchasers of new motor vehicles under Part 575.104(d)(1)(iii).; UTQGS applies to a tire type whose predominant contemplated use is o passenger cars, even if the manufacturer knows the tire type is also used as original equipment on multi-purpose passenger vehicles. A manufacturer's determination to certify a tire as conforming to Standard No. 109, will also determine the tire's classification for purposes of UTQGS. Thus, UTQGS would apply to any tire labeled with a size designation listed in Appendix A of Standard No. 109, other than a deep tread, winter-type snow tire or space- saver or temporary use spare tire, regardless of the tire's actual use.; On October 23, 1978, NHTSA issued a *Federal Register* notice (cop enclosed) granting the petition of American Motors corporation to revise the effective dates for Part 575.104(d)(1)(iii) to September 1, 1979 for bias-ply tires and March 1, 1980 for bias-belted tires. On the basis of this change, your statement regarding effective dates is correct.; Sincerely, Joseph J. Levin, Jr., Chief Counsel |
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ID: aiam1503OpenMr. Merle O. Robberts, Controller, Hellstar Corporation, 1600 N. Chestnut, Wahoo, NE 68066; Mr. Merle O. Robberts Controller Hellstar Corporation 1600 N. Chestnut Wahoo NE 68066; Dear Mr. Robberts: This is in response to your letter of May 13, 1974, requestin information concerning the existence of any Federal Motor Vehicle Safety Standards applicable to auxiliary fuel tanks.; The National Highway Traffic Safety Administration has promulgated n motor vehicle safety standard relating to auxiliary fuel tanks. There is, however, a safety standard which imposes performance requirements upon motor vehicles with regard to their fuel systems. Thus if installation of the auxiliary tank is accomplished prior to the first purchase of the vehicle for purposes other than resale causing the vehicle's fuel system not to be in compliance with the applicable safety standard, the person installing the tank or offering the vehicle for sale would be in violation of S108(a)(1) of the National Traffic and Motor Vehicle Safety Act. That would make the installer or seller subject to civil penalties of up to $1,000 for each violation.; The National Traffic and Motor Vehicle Safety Act authorizes th Secretary of Transportation to make a determination as to whether or not an item of motor vehicle equipment contains a defect which relates to motor vehicle safety. If he finds that a safety-related defect exists, he may compel the manufacturer to notify purchasers of the hazard. Therefore, even though auxiliary fuel tanks are not the subject of a standard, they still must be safely designed.; For your information, I have enclosed a copy of the Federal Safet Standard relating to motor vehicle fuel systems.; Yours truly, Richard B. Dyson, Assistant Chief Counsel |
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ID: aiam2877OpenMr. Ken Yoneyama, Chief Engineer, Bridgestone Research Inc., 350 Fifth Ave., Suite 4202, New York, NY 10001; Mr. Ken Yoneyama Chief Engineer Bridgestone Research Inc. 350 Fifth Ave. Suite 4202 New York NY 10001; Dear Mr. Yoneyama: This is in response to your letter of September 22, 1978, askin whether tires listed in Table 1-A of Appendix A, Federal Motor Vehicle Safety Standard No. 109, *New Pneumatic Tires - Passenger Cars*, must comply with Part 575.104, *Uniform Tire Quality Grading Standards*, (UTQGS), if the tires are installed as original equipment on multi-purpose passenger vehicles. You also inquire as to the effective dates for the provision of UTQGS information to first purchasers of new motor vehicles under Part 575.104(d)(1)(iii).; UTQGS applies to a tire type whose predominant contemplated use is o passenger cars, even if the manufacturer knows the tire type is also used as original equipment on multi-purpose passenger vehicles. A manufacturer's determination to certify a tire as conforming to Standard No. 109, will also determine the tire's classification for purposes of UTQGS. Thus, UTQGS would apply to any tire labeled with a size designation listed in Appendix A of Standard No. 109, other than a deep tread, winter-type snow tire or space- saver or temporary use spare tire, regardless of the tire's actual use.; On October 23, 1978, NHTSA issued a *Federal Register* notice (cop enclosed) granting the petition of American Motors corporation to revise the effective dates for Part 575.104(d)(1)(iii) to September 1, 1979 for bias-ply tires and March 1, 1980 for bias-belted tires. On the basis of this change, your statement regarding effective dates is correct.; Sincerely, Joseph J. Levin, Jr., Chief Counsel |
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ID: aiam3717OpenDavid I. Fallk, Esq., Robert W. Munley, P.C., Floor Eight, Penn Security Bank Building, P.O. Box 1066, Scranton, PA 18503; David I. Fallk Esq. Robert W. Munley P.C. Floor Eight Penn Security Bank Building P.O. Box 1066 Scranton PA 18503; Dear Mr. Fallk: This responds to your letter of July 11, 1983, concerning Standard No 121, *Air Brake Systems*, and the *PACCAR* case. The answers to your questions are as follows.; Your first question was whether, following *PACCAR*, a manufacturer wa required to comply with the applicable 121 standard for trucks which had been assembled but not delivered. The answer to that question is no, for the portions of the standard that were invalidated by the court. As noted in an enclosed letter (dated March 4, 1980), NHTSA concluded that the 'no lockup' and 60-mph stopping distances had been invalidated from the effective date of the standard. Therefore, after *PACCAR*, no manufacturer was required to comply with those invalidated portions of the standard, whether or not a vehicle had already been assembled.; Your second question concerned whether a manufacturer or anyone else i properly informed was prevented from disabling the anti-lock system, before it was put into service. The answer to that question is no. That issue is fully explained in two enclosed letters (dated September 11, 1979, and March 4, 1980). These letters explain the relationship of what your letter refers to as the section of the vehicle safety act to prevent disabling and Standard No. 121, in light of the *PACCAR* case.; I have also enclosed a letter (dated November 29, 1979), whic discusses the nature of Standard No. 121 as a performance standard. If you have any further questions, please call Edward Glancy of my staff at 202-426-2992.; Sincerely, Frank Berndt, Chief Counsel |
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ID: aiam2875OpenMr. Ken Yoneyama, Chief Engineer, Bridgestone Research Inc., 350 Fifth Ave., Suite 4202, New York, New York 10001; Mr. Ken Yoneyama Chief Engineer Bridgestone Research Inc. 350 Fifth Ave. Suite 4202 New York New York 10001; Dear Mr. Yoneyama: This is in response to your letter of September 22, 1978, askin whether tires listed in Table 1-A of Appendix A, Federal Motor Vehicle Safety Standard No. 109, *New Pneumatic Tires - Passenger Cars*, must comply with Part 575.104, *Uniform Tire Quality Grading Standards*, (UTQGS), if the tires are installed as original equipment on multi-purpose passenger vehicles. You also inquire as to the effective dates for the provision of UTQGS information to first purchasers of new motor vehicles under Part 575.104(d) (1) (iii).; UTQGS applies to a tire type whose predominant contemplated use is o passenger cars, even if the manufacturer knows the tire type is also used as original equipment on multi-purpose passenger vehicles. A manufacturer's determination to certify a tire as conforming to Standard No. 109, will also determine the tire's classification for purposes of UTQGS. Thus, UTQGS would apply to any tire labeled with a size designation listed in Appendix A of Standard no.l 109, other than a deep tread, winter-type snow tire or space-saver or temporary use spare tire, regardless of the tire's actual use.; On October 23, 1978, NHTSA issued a *Federal Register* notice (cop enclosed) granting the petition of American Motors Corporation to revise the effective dates for Part 575.105(d) (1) (iii) to September 1, 1979 for bias-ply tires and March 1, 1980 for bias-belted tires. On the basis of this change, your statement regarding effective dates is correct.; Sincerely, Joseph J. Levin, Jr., Chief Counsel |
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ID: aiam2577OpenMrs. Floyd J. Caron, Caron Service Center, Route 5, Box 16, Faribault, MN 55021; Mrs. Floyd J. Caron Caron Service Center Route 5 Box 16 Faribault MN 55021; Dear Mrs. Caron: This responds to your April 1, 1977, letter asking where you can obtai vehicle certification forms and a permit to undertake modifications of trucks to lengthen and shorten their frames.; The National Highway Traffic Safety Administration (NHTSA) promulgate regulations pertaining to vehicle safety. It is the responsibility of manufacturers to comply with the requirements of the agency. The NHTSA does not license manufacturers or alterers. Accordingly, you need not obtain a Federal permit to alter trucks in the manner you propose. Similarly, the NHTSA does not supply forms for vehicle certification. You may have these forms printed in the form provided by Part 567, *Certification*, of our regulations (copy enclosed). The type of manufacturing operation you describe would place upon you responsibility, as an alterer of the vehicle prior to first purchase for purposes other than resale, to ensure that the vehicle continues to comply with all applicable safety standards after your modifications. Under Part 567 of our regulations, you must attach a label to the vehicle that states that, as altered, the vehicle continues to conform to the standards.; I am enclosing an information sheet detailing where to obtain moto vehicle safety standards and regulations.; Sincerely, Frank Berndt, Acting Chief Counsel |
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ID: aiam0839OpenMr. Robert Barnett, Dallas Sales, Gardner-Denver Company, P.O. Box 26346, Dallas, TX 75226; Mr. Robert Barnett Dallas Sales Gardner-Denver Company P.O. Box 26346 Dallas TX 75226; Dear Mr. Barnett: This is in reply to your letter of August 4, 1972, to our Regiona Office in Fort Worth, Texas, that has been referred to me, in which you request information concerning intermediate and final stage manufacturers.; I am enclosing, among other things, a copy of Part 568 of Title 49 o the Code of Federal Regulations that specifies the responsibilities of intermediate and final stage manufacturers. The final stage manufacturer applies the 'Gross Axle Weight Rating' to the certification label in accordance with paragraph 567.5 of the Certification Regulation, a copy of Part 567 is also enclosed. The Preamble to Part 568 - Vehicles Manufactured in Two or More Stages, states '. . .By its definition a completed vehicle is one that requires no further manufacturing operations in order to perform its intended function, other than the attachment of readily attachable components and minor finishing operations. . . .'; 'In the event that a 'readily attachable component' is a componen regulated by the standard, such as a mirror or a tire, the final-stage manufacturer must assume responsibility and certify the vehicle even though he does not install the particular component. . . .' Persons who change tires, that are furnished by the final-stage manufacturer, prior to delivery to the user are not responsible for certification. However, he should assure himself that the tires he installs are compatible with the weight ratings on the certification label affixed by the final-stage manufacturer.; Final-stage manufacturers can rely on the documentation supplied by th incomplete and/or the intermediate vehicle manufacturer in establishing his weight ratings as long as he has no reason to believe it is false or does nothing in his operation that would change the ratings. Good business practices would dictate that a manufacturer would retain information supplied by other manufacturers that he uses as a basis for his certification.; If you have further questions, I will be pleased to answer them. Sincerely, Francis Armstrong, Director, Office of Standard Enforcement, Motor Vehicle Programs; |
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ID: aiam2027OpenMr. Jerry Toner, Consultant, Transportation, Traffic & Safety, Superintendent of Public Instruction, Old Capitol Bldg., Olympia, WA 98504; Mr. Jerry Toner Consultant Transportation Traffic & Safety Superintendent of Public Instruction Old Capitol Bldg. Olympia WA 98504; Dear Mr. Toner: This is in reply to your letter of July 15, 1975, to Mr. J. E. Leysat of this agency asking whether the State of Washington's proposed school bus light warning system conflicts with S4.1.4(b)(ii) of Federal Motor Vehicle Safety Standard No. 108.; That section requires an eight lamp signal system to be wired 'so tha the amber signal lamps are activated only by manual or foot operation, and if activated, are automatically deactivated and red signal lamps automatically activated when the bus entrance door is opened.' Under the system Washington proposes, when a school bus stops, a 'stop paddle sign' is extended by the operator, activating 'a switching system which will terminate the yellow flashing lights and start the red flashing lights,' before the door is opened.; Under the system you describe, the termination of the yellow lamps an activation of the red ones is dependent upon the operator extending the stop paddle sign. Should the operator forget to extend the sign, it does not appear that the system required by S4.1.4 would operate automatically when the door is opened. We therefore conclude that in order to meet S4.1.4 your school buses must be equipped with an override switch that would deactivate the amber lamps and activate the red ones when the door is opened, in the event that the stop paddle sign has not been extended.; Sincerely, Frank A. Berndt, Acting Chief Counsel |
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ID: aiam0941OpenMr. R. L. Coleman, Assistant Manager, Crawford and Company Insurance Adjusters, 4915 Augusta Avenue, Post Office Box 6473, Richmond, VA 23230; Mr. R. L. Coleman Assistant Manager Crawford and Company Insurance Adjusters 4915 Augusta Avenue Post Office Box 6473 Richmond VA 23230; Dear Mr. Coleman: This is in reply to your letter of September 19, 1972, concerning a accident involving a 1972 International tractor which you maintain was not certified by its manufacturer as complying with applicable Federal standards. You state that the accident may have been due to 'insufficient gross vehicle weight'.; The Certifications regulations (49 CFR Parts 567,568) do requir final-stage manufacturers to certify the conformity of vehicles they complete, by affixing to them a label containing information specified in the regulations. In the case of vehicles manufactured on or after january 1, 1972, the regulations require that such information include a gross vehicle weight rating, and a gross axle weight rating for each axle. These ratings are set by the manufacturer based on definitional criteria found in the regulations (S 568.3, 49 CFR S 571.3). Your definition of a 'final-stage' manufacturer, 'anyone who installs a component that is not readily attachable', is correct only if the component installation is to an incomplete vehicle.; Your letter has been forwarded to our Office of Standards Enforcement who will conduct whatever investigation is appropriate to determine whether violations of NHTSA regulations have occurred. Such an investigation does not include ascertaining the cause of any accident, or whether a particular vehicle may have been overloaded. It concerns only whether the respective manufacturers have complied with NHTSA regulations applicable to them. If you wish to know the results of this investigation when it is completed, you may write our Office of Standards Enforcement, NHTSA, or call Mr. George Shifflett of that office at (202) 426-1693.; 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.