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: aiam3543OpenMr. H. Nakaya, Mazda (North America), Inc., 23777 Greenfield Road, Suite 462, Southfield, MI 48075; Mr. H. Nakaya Mazda (North America) Inc. 23777 Greenfield Road Suite 462 Southfield MI 48075; Dear Mr. Nakaya: This responds to your letter asking a number of questions concernin the definition of Seating Reference Point (49 CFR 571.3). Your letter indicates that the questions arise from a concern that the definition may limit rearward seat track travel.; The agency recently published, in response to petitions for rulemaking an advance notice of proposed rulemaking (ANPRM) concerning the definition of Seating Reference Point. Among other things, the preamble to the notice explains that while the definition of Seating Reference Point establishes limitations on where manufacturers must locate that point, it does not prevent manufacturers from extending seat track travel behind the point. We have enclosed a copy of that notice for your convenience.; Your first question asks for an interpretation of the definition o Seating Reference Point. Among the interpretations you suggest, the one which is most nearly correct is the one which says the Seating Reference Point is the single self-determining point (no choice for the manufacturer) where the 90th percentile two- dimensional manikin should be positioned according to the SAE J826.; The enclosed notice explains that section (d) of the definition o Seating Reference Point requires manufacturers to use the 90th percentile template described in SAE Recommended Practice J826 in locating the Seating Reference Point. While manufacturers must use that template in locating the Seating Reference Point, there is some small leeway (using that device) as to where the point may actually be located. Thus, while your interpretation is partially correct, it is not correct to the extent that it suggests that there is no choice (as opposed to a limited choice) for the manufacturer.; The rest of your questions appear to involve the same issue, i.e. which version of an SAE Recommended Practice to use when a safety standard incorporates by reference an SAE Recommended Practice that has later been updated by SAE. The version which must be used is the one actually referenced by the standard. The fact that SAE updates one of its Recommended Practices does not change a Federal motor vehicle safety standard that incorporates an earlier version. Such a change would require the same type of rulemaking as any other amendment.; We believe that you will be able to answer your questions based on th foregoing discussion and the enclosed notice.; Sincerely, Frank Berndt, Chief Counsel |
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ID: aiam4286OpenMr. Tony U. Otani, Adyna Corporation, 6124 Candor Street, Lakewood, CA 90713; Mr. Tony U. Otani Adyna Corporation 6124 Candor Street Lakewood CA 90713; Dear Mr. Otani: This letter responds to your letter asking whether there are an regulations with which you must comply in producing an invention you call an Automotive Steering Wheel Stabilizing Aid. I regret the delay in this response.; You describe your product and include a picture. The article yo describe is a thick urethan rubber pad that a motor vehicle driver can fasten to the thigh with a band or buckle. The top part of this pad is contoured to fit under the steering wheel. You state that a driver can use this pad to apply pressure to the steering wheel, holding the wheel steady so that he may drive on a long distance highway when the course is straight. The driver then has his hands free.; Your product falls within the jurisdiction of the National Highwa Traffic Safety Administration (NHTSA) if it is an item of 'motor vehicle equipment' as that term is defined in S102(4) of the National Traffic and Motor Vehicle Safety Act. Section 102(4) defines 'motor vehicle equipment' in relevant part as follows:; >>>...any system, part, or component of a motor vehicle as originall manufactured or any similar part or component manufactured or sold for replacement or improvement of such system, part, or component, or as any *accessory*, or addition to the motor vehicle...(Emphasis added.)<<<; In determining whether an item of equipment is an 'accessory,' th agency assesses two factors: first, whether the item has no ostensible purpose other than use with a motor vehicle, and second, whether the item is intended to be used principally by ordinary users of motor vehicles. Under this framework, your invention is a motor vehicle accessory.; While NHTSA currently has no standard applicable to the kind o accessory you describe, the agency does not have authority to regulate your invention. Even in the absence of a standard, please note that if you decide to market this product, then under our regulations and the National Traffic and Motor Vehicle Safety Act, you have the responsibility to conduct notice and remedy campaigns if you or the agency later find that your product has a safety-related defect.; We are concerned with the safety consequences of your product. Thi kind of product may encourage a driver to take his hands from the steering wheel while he is operating a motor vehicle, and therefore may increase the risk of accident involving a motor vehicle. For example, removing one's hands from the steering wheel makes a driver less efficient in responding to any unanticipated road event that may require a quick change in vehicle direction. Further, a driver who feels free to do something with his hands other than steer the vehicle may not be devoting full time and attention to his driving.; I ask you to give these implications your fullest consideration, an hope you find this information helpful in making your decision.; Sincerely, Erika Z. Jones, Chief Counsel |
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ID: aiam1084OpenMr. Eric Feldmann, 113 West Broadway, Gettysburg, PA 17325; Mr. Eric Feldmann 113 West Broadway Gettysburg PA 17325; Dear Mr. Feldmann: Thank you for your letter of March 23, 1973, concerning Federal Moto Vehicle Safety Standard No. 215, Exterior Protection.; Your first concern is the fact that bumpers which comply with Standar No. 215 still permit damage to occur to the vehicle during low- speed impacts. This situation occurs because Standard No. 215, which initially became effective on September 1, 1972, was developed in accordance with the National Traffic and Motor Vehicle Safety Act of 1966. This Act provided the authority to develop standards to improve vehicle safety during collisions, not solely to reduce property damage. The authority to develop bumper standards primarily to reduce property damage, the Motor Vehicle Information and Cost Savings Act, became law on October 20, 1972. As the result of this new Act, we are in the process of developing standards which limit automobile damage in low-speed bumper impacts.; Secondly, you cite the mismatch problems that continue to exist amon passenger car bumpers. Commencing with 1974 model cars, Standard No. 215 specifies requirements directed at correcting the mismatch problems that cause damage to safety-related components during low-speed, car-to-car collisions. It establishes a uniform interfacing surface among all cars that reduces the likelihood of override, underride, and interlock, all of which are quite prevalent with existing bumper designs.; Thirdly, you express concern over the numerous collisions involvin damage to corners of vehicles. Standard No. 215 also specifies requirements for 1974 model cars that will provide improved corner protection. A copy of the standard is enclosed for your use.; Lastly, you indicate the availability of inexpensive energy absorbin devices that could be used to manage the low-speed crash forces. We are aware of these and other devices of this type, however, as you will note, Standard No. 215 specifies minimum performance only without specifying the equipment or configuration to be used. We feel that this approach encourages competitive innovation and promotes technological progress to achieve the desired performance at minimum cost to the consumer.; We appreciate receiving your comments and your interest in improvin motor vehicle safety.; Sincerely, Robert L. Carter, Associate Administrator, Motor Vehicl Programs; |
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ID: aiam3810OpenMr. Louis Lemmens, Decoba N.V., 3500 Hasselt, Vaarstraat 4, Belgium; Mr. Louis Lemmens Decoba N.V. 3500 Hasselt Vaarstraat 4 Belgium; Dear Mr. Lemmens: This responds to your letter to this office seeking information o requirements applicable to retreaded truck tires imported into the United States. Specifically, you asked whether a foreign-based retreader would be required to put another tire identification number on the tires it retreads, or whether that retreader could simply leave the original manufacturer's identification number on the retreaded tire. As explained below, the retreader is required to mark its own tire identification number on each tire it retreads. You then asked for information on how a retreader obtains an identification number, and this procedure is set forth below.; For your information, I have enclosed a copy of 49 CFR Part 574, *Tir Identification and Recordkeeping*. Section 574.5 specifies that *each* tire retreader shall permanently label one sidewall of *each* tire he retreads with the information specified in that section. For a retreader, the first group of three symbols in the identification number would represent the retreader's assigned identification mark, the second group of two symbols would identify the retread matrix in which the tire was processed, the third group of four symbols may be used to identify characteristics of the tire at the retreader's option, and the fourth group of three symbols would identify the week and year in which the tire was retreaded.; Section 574.6 explains the procedures to be followed by the retreade in applying for an identification mark, and specifies the information which must be provided by the retreader. The agency usually assigns the identification mark within two weeks of receiving the necessary information from a retreader.; However, a retreader identification mark will not be assigned until th retreader has designated an agent for the service of process, according to the requirements of 49 CFR S551.45 (copy enclosed). That section specifies that, for a designation of agent to be valid, it must contain the following six items:; 1. A certification that the designation is valid in form and binding o the retreader under the laws, corporate by-laws, or other requirements governing the making of the designation at the time and place where it is made,; 2. The full legal name, principal place of business, and mailin address of the retreader,; 3. Marks, trade names, or other designations of origin of any of th retreader's products which do not bear his name,; 4. A statement that the designation shall remain in effect unti withdrawn or replaced by the manufacturer,; 5. A declaration of acceptance duly signed by the agent appointed which may be an individual, a firm, or a U.S. corporation, and; 6. The full legal name and address of the designated agent. In addition, the designation must be signed by one with authority t appoint the agent, and the signer's name and title should be clearly indicated beneath his signature. This designation should be mailed to the address shown in S551.45(b). When this agency has received both a completed application for a retreader identification mark and a designation of agent, a code mark will be assigned to the retreader promptly. This identification mark will be sent directly to the retreader and not to the designated agent.; Please feel free to contact me should you need any further informatio in this matter.; Sincerely, Frank Berndt, Chief Counsel |
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ID: aiam2702OpenMr. William H. Loughran, President, Rocky Mountain Bandag, 12540 west Ceder Drive, Box 26224, Denver, Colorado 80226; Mr. William H. Loughran President Rocky Mountain Bandag 12540 west Ceder Drive Box 26224 Denver Colorado 80226; Dear Mr. Loughran: This responds to your October 19, 1977, letter asking whether th National Highway Traffic Safety Administration (NHTSA) has regulations that prohibit the use of retreaded tires on steering axles. The NHTSA has performance regulations applicable to retreaded passenger car tires. The agency does not regulate the use of retreaded tires that meet those performance requirements. You should note that the Bureau of Motor Carrier Safety has regulations (49 Code of Federal Regulations Part 393.75(d)) that prohibit the use of retreaded tires on the front wheels of buses under their jurisdiction. They do not prohibit the use of such retreaded tires on the steering axle of trucks, however.; Sincerely, Joseph J. Levin, Jr., Chief Counsel |
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ID: aiam5497OpenMr. Steve Anthony Product Manager Structural Composites Industries 325 Enterprise Place Pomona, CA 91768; Mr. Steve Anthony Product Manager Structural Composites Industries 325 Enterprise Place Pomona CA 91768; "Dear Mr. Anthony: This responds to your inquiry about Federal Moto Vehicle Safety Standard (FMVSS) No. 304, Compressed Natural Gas (CNG) Fuel Container Integrity, which takes effect on March 27, 1995. I apologize for the delay in our response. You stated that you manufacture CNG containers for OEMs. You further stated that some of your customers have requested that containers they purchase prior to FMVSS No. 304's effective date be labeled with a statement that they comply with FMVSS No. 304. Specifically, you asked whether your containers could be labeled with the statement 'This CNG container meets the requirements of DOT FMVSS No. 304 effective March 27, 1995' or 'DOT effective March 27, 1995.' As explained below, prior to the effective date, you are prohibited from labeling a container with information that could appear to be a certification to the FMVSS. In the preamble to the final rule establishing FMVSS No. 304, NHTSA stated that a manufacturer may not certify a container as meeting the equipment standard until the standard goes into effect. Under the Vehicle Safety Act, a certification is a statement that a vehicle or item of equipment meets all applicable Federal Motor Vehicle Safety Standards that are then in effect. Therefore, until a standard is effective, manufacturers may not certify compliance with it (59 FR 49010, 49020 September 26, 1994). Based on this discussion, you acknowledge that it would be impermissible for a manufacturer to include the symbol DOT on CNG containers manufactured prior to March 27, 1995. Nevertheless, you wish to specify information on the container that the container will comply with the soon to be effective FMVSS. As discussed in our September 1994 notice, a manufacturer may not certify a container as meeting the equipment standard until the standard goes into effect. Any label on a product about meeting a standard tends to create the appearance of a certification. It is therefore our opinion that, along with not using the symbol DOT, any such statement on a container label must affirmatively indicate that (1) no standard applies to the container, and (2) the statement is not a certification. With these considerations in mind, your suggestion to include the statement 'This CNG container meets the requirements of DOT FMVSS No. 304 effective March 27, 1995' would not be permissible because it might be read as constituting a certification. Moreover, the symbol DOT may not be included in your statement because its inclusion might be misinterpreted as implying that the container has been certified to an FMVSS that is in effect, since use of the DOT symbol is the usual method by which certifications are made. You may, however, label a container with the following statement: 'This CNG container would comply with the requirements of Federal Motor Vehicle Safety Standard (FMVSS) 304, that takes effect on March 27,1995. However, since this container was manufactured before the effective date of FMVSS 304, it cannot be certified to comply with that standard. No FMVSS applies to the container.' I hope you find this information helpful. If you have any other questions, please contact Marvin Shaw at this address or by phone at (202) 366-2992. Sincerely, Philip R. Recht Chief Counsel"; |
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ID: aiam2352OpenMr. Warren M. Heath, Commander, Engineering Section, Department of California Highway Patrol, P.O. Box 898, Sacramento, CA 95804; Mr. Warren M. Heath Commander Engineering Section Department of California Highway Patrol P.O. Box 898 Sacramento CA 95804; Dear Mr. Heath: This is in reply to your letter of June 22, 1976, asking fo interpretations of Motor Vehicle Safety Standards Nos. 108 and 205.; Paragraph S4.3.1 of Standard No. 108 requires, as you noted, that lamp and reflective devices be securely mounted on a rigid part of the vehicle. You asked 'whether or not flexible mount clearance and sidemarker lamps should be permitted for use on motor vehicles.' Your question appears directed towards replacement equipment. The answer is that California may regulate mounts for replacement lighting equipment in the manner it deems appropriate. S4.3.1 applies to the mounting of lighting equipment on new motor vehicles, and does not establish a specification for replacement equipment mounts. The replacement clearance and sidemarker lamps themselves are, of course, subject to Standard No. 108.; You also asked whether there was a provision in Standard No. 205 *Glazing Materials*, that would exempt 'Item 3' [AS 3] glazing (to be used for glass partitions and rear side windows of van-type vehicles) from the requirements of ANS Z26 Tests Nos. 1 and 18.; The answer to your question is no. Paragraph S5.1.1 of Standard No. 20 specifies that glazing materials for use in motor vehicles shall conform to the requirements of ANS Z26. The ANS Z26 specifications require 'Item 3' glazing materials to comply with Test No. 1, 'Light Stability,' and Test No. 18, 'Abrasion Resistance,' regardless of where the 'Item 3' glazing is to be used in the vehicle. Thus, there is no provision by which manufacturers of such glazing may be exempted from the test requirements.; Sincerely, Frank A. Berndt, Acting Chief Counsel |
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ID: aiam1987OpenMr. J. W. Boyd, Manager, Government & Industry Technical Relations, Dunlop Tire and Rubber Corporation, Box 1109, Buffalo, NY 14240; Mr. J. W. Boyd Manager Government & Industry Technical Relations Dunlop Tire and Rubber Corporation Box 1109 Buffalo NY 14240; Dear Mr. Boyd: This is in response to your letter of July 1, 1975 (NA-2637A) forwarded to us by the Tire Division, which requests comments on the issues raised by two letters from Mr. R. G. Clifton of Dunlop U.K.; Mr. Clifton's first concern is with respect to the prope interpretation of section 159(2) of the 1974 amendments to the National Traffic and Motor Vehicle Safety Act (15 U.S.C. 1419). Section 159 provides that the definitions of 'original equipment' and 'replacement equipment' in section 159 may be changed 'as otherwise provided by Regulations of the Secretary.' This phrase does not mean that the definitions may be changed by *any* regulation, but rather that the definitions may be changed by a regulation implementing sections 151-60 of the 1974 amendments, to which the provisions of section 159 specifically apply. Therefore, a definition of 'tire manufacturer' in a regulation issued pursuant to some other statutory provision has no effect on the definitions of 'original equipment' and 'replacement equipment' in section 159. No specific regulation has yet been issued by the National Highway Traffic Safety Administration (NHTSA) modifying the provisions of section 159, although such a regulation is currently under consideration.; Mr. Clifton's second concern was that no amendments to Part 573 hav been proposed in order to make tire and equipment manufacturers subject to defect reporting requirements, as required by the 1974 amendments. The NHTSA is preparing to issue proposed amendments to Part 573 which will reflect this requirement.; Mr. Clifton's third concern, expressed in his letter of June 3, wa that section 159(2)(D) of the 1974 amendments would make the motor vehicle manufacturer totally responsible for the original equipment tires on his vehicles. Although section 159 places the legal responsibility for notification and remedy of safetyrelated (sic) defects in original equipment on the vehicle manufacturers, it does not lessen the obligation of the tire manufacturers to ensure that their tires contain no safety-related defects. Tire manufacturers do have an obligation to notify of and remedy defects in tires used as replacement equipment.; We trust this has been helpful. 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: aiam0695OpenMr. Bernard Belier, U.S. Resident Engineer, CITROEN, 801 Second Avenue, New York, NY 10017; Mr. Bernard Belier U.S. Resident Engineer CITROEN 801 Second Avenue New York NY 10017; Dear Mr. Belier: This is in reply to your letter of April 24, 1972, in which you pose questions about the operation of the seat belt warning system under Standard 208 and about the intent of the headlamp adjustment requirement under Standard 215.; Your questions on Standard 208 deal with the requirement in S7.3.3 tha the warning system in a vehicle with an automatic transmission must not operate when the engine is operating and the gear selector is in the 'Park' position. In answer to your first question, if the two conditions for non-operation exist, the warning system must not operate, regardless of the position of the hand brake lever. If either condition does not exist, e.g., the transmission is in 'Park' but the engine is not operating, it would be permissible to have the system operate, and its operation could be controlled by the hand brake so long as the hand brake circuitry does not interfere with the mandatory operation of the system under S7.3.1 and S7.3.5.; If the shift is in the neutral position, as stated in your secon question, you are free to choose whether to have the system operate or not, since S7.3 does not require either operation or non-operation when the transmission is in neutral.; In response to your last question on Standard 208, an 'operatin engine' is an engine that is rotating. It is permissible to have a system in which the warning operates when the transmission is in 'Park' and the ignition is 'On', but the warning must shut off when the engine begins to operate.; Your question on Standard 215 is whether the headlamps must b adjustable after the tests 'so as to permit restoration of normal lighting' or whether it is sufficient for the lamps to be adjustable plus or minus 4 degrees vertically and horizontally whether or not this restores normal lighting. Our reply is that the requirement is intended to provide for the safe operation of the lamps after impact and that the lamps must therefore be adjustable in a manner that restores normal lighting.; Sincerely, Richard B. Dyson, Assistant Chief Counsel |
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ID: aiam0318OpenMr. Donald M. Schwentker, Busby, Rivkin, Sherman and Levy, 816 Connecticut Avenue, N.W., Washington, DC 20006; Mr. Donald M. Schwentker Busby Rivkin Sherman and Levy 816 Connecticut Avenue N.W. Washington DC 20006; Dear Mr. Schwentker: This is in response to your letter of April 20, 1971, in which yo enclosed a request for clarification, on behalf of Rolls-Royce, Ltd., of the requirements of Standard No. 208, Occupant Crash Protection. Essentially, the question was whether a 'European type combined lap and diagonal strap seat belt assembly with retractor' could be furnished instead of the 'Type 1 seatbelt assembly' specified in the second protection option on passenger cars manufactured from August 15, 1973, to August 14, 1975.; Standard No. 208 does not permit this substitution. The key feature o the second option in the August 1973-August 1975 period is that the manufacturer must design his vehicles so that the front seat occupants are protected from injury when restrained with lap belts only, and provide lap belts for all occupants that may, at least, be separately usable as such. A detachable upper torso belt may be provided at the manufacturer's option. The basis for this requirement is the well-documented finding that a much larger percentage of the American public will fasten lap belts than will use upper torso belts, whether the latter are of the detachable or the combination type.; We are pleased to be of assistance. Sincerely, Lawrence R. Schneider, Acting 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.