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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| search results table | |
ID: aiam1022OpenMs. Claire Cannon, Center for Auto Safety, Post Office Box 7250, Washington, DC 20044; Ms. Claire Cannon Center for Auto Safety Post Office Box 7250 Washington DC 20044; Dear Ms. Cannon: This is in reply to your letter of February 14, 1973, concerning ou plans for publicizing the new Federal odometer requirements.; To begin with your third question, the NHTSA does not have th authority to require State departments of motor vehicles to notify the public of the odometer requirements. Because the participation of the States is voluntary, and not subject to regulation, we have not attempted to instruct the States in our regulatory notices. The approach you suggested, of sending notice of the Federal law with the auto registration cards, would be useful, particularly in States whose forms cannot be readily converted to contain the disclosure statement. This is one of the publicity measures that we are discussing with the States at the present time.; In the short run, we are going to have to rely on the public media t distribute information about the requirements. We issued press releases upon issuance of the notices establishing the requirement, and have been encouraging the press to highlight the problems of odometer tampering and to tell of the existence of the disclosure requirements. These efforts fall short, however, of providing the type of general coverage needed for regulations having a national effect. It is likely that most consumers will learn of the requirements from automobile dealers, most of whom have been advised of the requirements by their national dealer associations.; The problem of odometer fraud deserves full exposure, and we intend t do what we can to expose it. The scale of our long term efforts, however, including the question of the use of TV spots, is a matter that has not been resolved as yet.; Yours truly, Richard B. Dyson, Assistant Chief Counsel |
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ID: aiam5061OpenMr. Kevin R. Boyne Chief Engineer Dynamics and Durability Engineering Transportation Research Center Inc. East Liberty, OH 43319-0367; Mr. Kevin R. Boyne Chief Engineer Dynamics and Durability Engineering Transportation Research Center Inc. East Liberty OH 43319-0367; "Dear Mr. Boyne: This responds to your letter requesting clarification of the requirements of S4.2.1 of Standard No. 114, Theft Protection. That section sets forth new requirements relating to key removal, which became effective on September 1, 1992. Your letter asks whether a vehicle which operates in the following manner would meet the requirements: Initial Condition - Engine running and shift lever positioned in 'drive'. Action - The operator depresses the thumb button on the left side of the shift lever and moves the shift lever to the 'park' position. Point of Concern - As long as the thumb button is held in the depressed position, the ignition key can be rotated to the lock position and removed. Still holding the thumb button, the shift lever can later be moved to any position. Removal of the key will only occur in the 'park' position. As discussed below, it is our opinion that a system which operates in the manner you described would comply with S4.2.1 of the standard for vehicles manufactured before September 1, 1993, but not for vehicles manufactured after that time. This assumes, for vehicles manufactured before September 1, 1993, that steering is prevented after removal of the key. It also assumes that the system does not otherwise permit removal of the key when the transmission is not locked in park. By way of background information, the National Highway Traffic Safety Administration (NHTSA) does not provide approvals of motor vehicles or motor vehicle equipment. Under the National Traffic and Motor Vehicle Safety Act, it is the responsibility of the manufacturer to ensure that its vehicles or equipment meet applicable standards. The following represents our opinion based on the facts provided in your letter. Section S4.2.1 of Standard No. 114 states: Except as provided in S4.2.2(a) and (b), the key-locking system required by S4.2 in each vehicle which has an automatic transmission with a 'park' position shall prevent removal of the key unless the transmission or transmission shift lever is locked in 'park' or becomes locked in 'park' as the direct result of removing the key. The system which you describe appears to permit removal of the key in a situation when both the transmission and transmission shift lever are not locked in 'park' and when they do not become locked in 'park' as the direct result of removing the key. This conclusion follows from the fact that, following the removal of the key, the shift lever can be moved to any position. Therefore, the system you describe would not comply with S4.2.1 unless one of the exceptions in section S4.2.2(a) and (b) apply. The exception set forth in S4.2.2(a) only applies in the event of electrical failure and is therefore not relevant to the system you describe. S4.2.2(b) of Standard No. 114 reads as follows: (b)(1) Notwithstanding S4.2.1, each vehicle specified therein may have a device which, when activated, permits moving the transmission shift lever from 'park' after the removal of the key provided that steering is prevented when the key is removed. (2) For vehicles manufactured on or after September 1, 1993, the means for activating the device shall either be operable by the key, as defined in S3, or by another means which is covered by a non-transparent surface which, when installed, prevents sight of and activation of the device and which is removable only by use of a screwdriver or other similar tool. NHTSA included this second exception to allow for a manual override of the transmission shift lock so that a disabled vehicle could be moved. The requirement that such devices either be operable by the key or by another means which is covered by a non-transparent surface originally had an effective date of September 1, 1992. However, after considering petitions for reconsideration, NHTSA decided to provide an additional year's leadtime, noting that this would lessen the impacts associated with such redesign of the emergency override buttons of a number of systems. While the agency was primarily concerned about emergency override buttons in drafting S4.2.2(b), it is our opinion that the language in (b)(1) is sufficiently broad to include the thumb button on a transmission shift lever itself, i.e., the button can be considered a device which, when activated, permits moving the transmission shift lever from 'park' after the removal of the key. Therefore, assuming that steering is prevented after the removal of the key, the system you describe would come within the exception provided in S4.2.2(b)(1). Effective September 1, 1993, of course, such a device must also meet the requirements set forth in S4.2.2(b)(2) in order to come within this exception to S4.2.1. The system you describe would not fall within the exception at that time. The thumb button is not 'the key, as defined in S3.' In addition, the thumb button is not 'covered by a non-transparent surface which, when installed, prevents sight of and activation of the device and which is removable only by use of a screwdriver or other similar tool.' Therefore, based on the information you have provided, the system would not comply with S4.2.1 for vehicles manufactured on or after September 1, 1993. I hope you find this information helpful. If you have any other questions, please contact Mary Versailles of my staff at this address or by phone at (202) 366-2992. Sincerely, Paul Jackson Rice Chief Counsel"; |
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ID: aiam0799OpenMr. J. C. Eckhold, Director, Automotive Safety Office, Ford Motor Company, The American Road, Dearborn, MI 48121; Mr. J. C. Eckhold Director Automotive Safety Office Ford Motor Company The American Road Dearborn MI 48121; Dear Mr. Eckhold:This is in reply to your letter of July 26, 1972 concerning the adjustment of a tractor's fifth wheel under the test conditions proposed in Docket 70-17, Notice 5.; You state that it is not possible to load the tractor to its GVWR wit the tractor's nonsteerable axles and the trailer's axles at GAWR if the fifth wheel is set in more than one position. If this is the case, and the correct loading can be obtained with the fifth wheel in one position only, then only that position will be used in compliance testing. If more than one position can be used to produce the correct loading, the tractor must conform to the requirements of the standard with the fifth wheel at any such position.; Sincerely, Richard B. Dyson, Assistant Chief Counsel |
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ID: aiam2679OpenMr. Stephen C. Nimmer, Senior Supervising Engineer, Oshkosh Truck Corporation, Box 2566, Oshkosh, WI 54901; Mr. Stephen C. Nimmer Senior Supervising Engineer Oshkosh Truck Corporation Box 2566 Oshkosh WI 54901; Dear Mr. Nimmer: This is in reply to your letter of August 29, 1977, asking fo confirmation of your interpretation of S4.5.4 of Motor Vehicle Safety Standard No. 108.; Paragraph S4.5.4 requires that 'The stop lamps on each vehicle shall b activated upon application of the service brakes.' Oshkosh trucks are equipped with split air brake systems. This system incorporates a parking brake system on the rear axles. You indicated that there are three conditions under which the parking brakes will apply:>>>; Condition 1. - Parking Application. The spring brakes are driver applied through a hand operated parkin control.; Condition 2. - Rear Service Brake System Failure. The spring brakes can be driver applied through the service brake foo operated treadle valve control in the event of a failure in the rear service brake system.; Condition 3. - Spring Brake Cavity Pressure Loss. A component failure which allows air pressure to exhaust from th spring cavity of the rear brake chambers will cause the spring brakes (parking brakes) to apply. This condition is not driver initiated.'<<<; You have interpreted Condition 2 as the only 'services brake application since it is the only one of the three that is driver-initiated through the service brake control, and that stop lamp activation under the other two Conditions is not required by Standard No. 108.; This will confirm your interpretation. With respect to Condition 1, w do not consider that driver application of the parking brake portion of the service brake system is 'application of the service brakes' within the meaning of S4.5.4. Nor do we consider that activation of the parking brakes through component failure is 'application of the service brakes', your Condition 3.; Sincerely, Frank Berndt, Deputy Chief Counsel |
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ID: aiam5446OpenMr. Michael Winzkowski FABA Autoglas Produktion c/o Farmont Sunroofs, Ltd. 2346 Success Drive P.O. Box 981 Odessa, FL 33556-0981; Mr. Michael Winzkowski FABA Autoglas Produktion c/o Farmont Sunroofs Ltd. 2346 Success Drive P.O. Box 981 Odessa FL 33556-0981; "Dear Mr. Winzkowski: This responds to your letter about manufacturer's certification responsibilities under Federal Motor Vehicle Safety Standard No. 205, Glazing materials (49 CFR 571.205, copy enclosed). You state that you are a United States-based subsidiary of a German automotive sunroof manufacturer. You are having problems explaining to the German authorities the differences between the certification requirements of the two countries and request a letter explaining that the U.S. uses a self-certification procedure. I am pleased to provide this information. As you know, every item of glazing for use in motor vehicles that is sold in or imported into this country must be certified as complying with FMVSS No. 205. This standard sets forth both performance and labeling requirements that must be satisfied by the automotive glazing. In enforcing its safety standards, the National Highway Traffic Safety Administration (NHTSA), which is part of the U.S. Department of Transportation, does not follow the European practice of requiring the manufacturer of motor vehicle equipment to deliver an item of the equipment to specified institutes for testing before the product can be sold. Instead, as required by the U.S. Congress, the manufacturer 'self-certifies' that each of its items of motor vehicle equipment fully satisfies all requirements of the applicable Federal motor vehicle safety standards. Thus, each item of automotive glazing is self-certified by its manufacturer as complying with FMVSS No. 205. NHTSA does not require that the manufacturer's certification be based on a specified number of tests of the glazing or on any tests at all. Under the statute, the agency only requires that the certification be made with the exercise of 'due care' on the part of the manufacturer. It is up to the manufacturer to determine what data, test results, or other information is needed to enable it to certify that the glazing complies with Standard No. 205. We do recommend, however, that a manufacturer selling its glazing in the United States for the first time test those products, according to the test procedures specified in Standard No. 205. Once the manufacturer has determined that its glazing complies with the requirements of Standard No. 205, it certifies that compliance by marking the glazing with the symbol DOT, as specified in section S6 of Standard No. 205. You specifically asked for verification that 'no US DOT testing or certification is conducted when DOT numbers are assigned to manufacturers.' The 'DOT number' to which you refer is the manufacturer's code mark that is assigned by NHTSA on request of the glazing manufacturer (S6.2 of FMVSS No. 205). Your understanding is correct. NHTSA does not test glazing products or review manufacturers' compliance data prior to or as a condition for assigning a manufacturer's code mark pursuant to S6.2 of Standard No. 205. I hope you find this information helpful. If you have any other questions, please contact Mr. Marvin Shaw of my staff at (202) 366-2992. Sincerely, John Womack Acting Chief Counsel Enclosure"; |
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ID: aiam2383OpenMr. Richard J. Brandewie, Program Manager, B.F. Goodrich Engineered Systems Company, P.O. Box 340, Troy, OH 45373; Mr. Richard J. Brandewie Program Manager B.F. Goodrich Engineered Systems Company P.O. Box 340 Troy OH 45373; Dear Mr. Brandewie: This responds to your July 26, 1976, question whether the 'no lockup requirement of S5.3.1 and S5.3.2 of Standard No. 121, *Air Brake Systems*, requires wheel sensors on both axles of a tandem axle system in those cases where the 'no lockup' performance is provided by means of an antilock system. I have enclosed a detailed discussion of this issue that responded to a similar question from another manufacturer. The response should answer your question.; Yours truly, Frank Berndt, Acting Chief Counsel |
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ID: aiam0214OpenMr. C. J. Newman, Director of Engineering, The Grote Manufacturing Company, State Route 7, P. O. Box 766 N. M. S., Madison, IN 47250; Mr. C. J. Newman Director of Engineering The Grote Manufacturing Company State Route 7 P. O. Box 766 N. M. S. Madison IN 47250; Dear Mr. Newman: Thank you for your letter of February 19, 1970, to Mr. Julian E Leysath of this Office asking for suggestions on lighting equipment for a trailer manufactured by Toter, Inc.; This will confirm your understanding that the Toter is considered trailer under the Federal Motor Vehicle Safety Standards, and not a dolly. Since the manufacturer is responsible for compliance with Federal Standard No. 108 (Lamps, Reflective Devices, and Associated Equipment) I am unable to provide specific suggestions or recommendations for lighting the vehicle in question.; Sincerely, Rodolfo A. Diaz, Acting Director, Motor Vehicle Safet Performance Service; |
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ID: aiam2229OpenMrs. Anderson, Inertia Switch, Ltd., Hardings Lane, Hartley Wintney, Hampshire, England RG278QA; Mrs. Anderson Inertia Switch Ltd. Hardings Lane Hartley Wintney Hampshire England RG278QA; Dear Mrs. Anderson: I am writing in response to your March 9, 1976, telephone conversatio with Mark Schwimmer of this office concerning the meaning of 'GVWR' as it appears in Federal Motor Vehicle Safety Standard No. 301-75, *Fuel System Integrity*.; 'GVWR' or 'Gross vehicle weight rating' is defined in 49 CFR 571.3 as: >>>the value specified by the manufacturer as the loaded weight of single vehicle.<<<; One constraint on this specification is found in S567.4(g)(3) of 49 CF Part 567, *Certification*, which requires that the GVWR shall not; >>>be less than the sum of the unloaded vehicle weight, rated carg load, and 150 pounds times the vehicle's designated seating capacity... .<<<; An information sheet entitled 'Where to Obtain Federal Motor Vehicl Safety Standards and Regulations' is enclosed for your convenience. If you have any further questions, please do not hesitate to write.; Yours truly, Richard B. Dyson, Assistant Chief Counsel |
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ID: aiam5016OpenThe Honorable John J. Duncan, Jr. House of Representatives Washington, DC 20515-4202; The Honorable John J. Duncan Jr. House of Representatives Washington DC 20515-4202; Dear Mr. Duncan: Thank you for your letter enclosing correspondenc from your constituent, Mr. Clarence Lowe, an instructor for Campbell County Comprehensive High School, concerning the use of 15-passenger vans to transport school children. Campbell County has been informed by the Tennessee State Department of Education that vans cannot be used to transport children to school or school-related events. In light of school budget constraints, Mr. Lowe would like to use these vehicles for transporting students to off-campus vocational programs. Your letter also enclosed a letter from Ernest Farmer, Tennessee Director of Pupil Transportation, explaining why the State of Tennessee has instructed schools not to use vans to transport school children. I am pleased to have this opportunity to clarify Federal law as it relates to school buses. The National Highway Traffic Safety Administration (NHTSA) has the authority under the National Traffic and Motor Vehicle Safety Act to issue motor vehicle safety standards that apply to the manufacture and sale of new motor vehicles, in order to reduce the number of fatalities and injuries that result from motor vehicle crashes. Under NHTSA's regulations, vans are generally classified as either multipurpose passenger vehicles (MPV's) or buses. The MPV category includes vans which carry 10 persons or less, vans which carry more than 10 persons are buses. Thus, the 15-passenger vans referred to by Mr. Lowe are classified as buses. Under the agency's definitions, a 'school bus' is a type of bus sold for transporting students to and from school or school-related events. All MPV's and buses are required to meet Federal motor vehicle safety standards. However, in the legislative history of the School Bus Safety Amendments of 1974, Congress stated that school transportation should be held to the highest level of safety. Accordingly, NHTSA has issued special Federal motor vehicle safety standards applicable to all new school buses. Like all safety standards, NHTSA's school bus standards impose obligations on the manufacturers and sellers of new motor vehicles, not upon the subsequent users of these vehicles. It is a violation of Federal law for any person to sell any new vehicle that does not comply with all school bus safety standards if the vehicle capacity is more than 10 persons, and if the seller is aware that the purchaser intends to use the vehicle as a school bus. On the other hand, without violating any provision of Federal law, a school may use a vehicle which does not comply with Federal school bus regulations to transport school children. This is so because the individual States, not the Federal government, have authority over the use of vehicles. However, I would like to call your attention to a guideline that NHTSA has issued under the authority of the Highway Safety Act of 1966. That Act authorizes the agency to issue guidelines for states to use in developing their highway safety programs. NHTSA issued Highway Safety Program Guideline 17, Pupil Transportation Safety, to provide recommendations to the states on various operational aspects of their school bus and pupil transportation safety programs. Guideline 17 recommends that any vehicle designed for carrying more than 10 persons which is used as a school bus comply with all safety standards applicable to school buses at the time the vehicle was manufactured. In conclusion, it is not a violation of Federal law for Campbell County to use its 15-passenger vans for transportation of school children, however, use of these vehicles may be restricted by Tennessee law. I must emphasize NHTSA's position that a vehicle meeting Federal school bus regulations is the safest way to transport students. Despite the additional cost of these vehicles, I encourage Campbell County to give its most careful consideration to the possible consequences of transporting students in vehicles that do not comply with these regulations. I hope this information is helpful. Sincerely, Jerry Ralph Curry; |
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ID: aiam3068OpenMr. G. Frinken, Manager, Automotive Engineering Europe, Uniroyal European Tire Development Center, Uniroyal GMBH, Postfach 410, 5100 Aachen 1, West Germany; Mr. G. Frinken Manager Automotive Engineering Europe Uniroyal European Tire Development Center Uniroyal GMBH Postfach 410 5100 Aachen 1 West Germany; Dear Mr. Frinken: This is in response to your letter of July 20, 1979, concerning th Uniform Tire Quality Grading (UTQG) Standards (49 CFR 575.104). You ask whether it is permissible under the regulation to mold UTQG grades on only one sidewall of a tire and, in the case of a symmetrical black sidewall tire, whether the grades may be molded on the same sidewall as the tire identification number required by 49 CFR 574.5.; The UTQG Standards require that tire grades need be molded on only on sidewall of a tire. Since the regulation presently does not specify the sidewall on which tire grades must be molded, Uniroyal is legally permitted to mold UTQG grades on either sidewall of its tires. However, in order to facilitate consumer access to the grading information, the National Highway Traffic Safety Administration (NHTSA) encourages manufacturers to mold tire grades on the sidewall intended to be visible when the tire is mounted on a vehicle. NHTSA will monitor the placement of tire grades to determine whether further action is necessary to assure the accessibility of the grading information.; 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.