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: aiam3018OpenMr. David L. Kelly, Pullman Trailmobile, 200 East Randolph Drive, Chicago, Illinois 60601; Mr. David L. Kelly Pullman Trailmobile 200 East Randolph Drive Chicago Illinois 60601; Dear Mr. Kelly: This is in response to your letter of January 12, 1979, requesting a interpretation of the term 'production process' as used in 49 CFR 571.115, S4.5.3.3. We are sorry for the delay in responding.; The production practice you describe on page 2 of your letter woul satisfy S4.5.3.3. In the preamble to the final rule published on August 17, 1978 (43 FR 36451), the agency stated:; >>>The NPRM proposed that the last six characters represent th sequential number of a vehicle when the manufacturer produced more than 500 vehicles annually of that type.; A number of comments pointed out that for various reasons a vehicl might be taken from a production line, thereby having an actual sequential number which differs from the production sequence number originally assigned by the manufacturer. The proposal is amended to indicate that the production sequence number is required.<<<; Thus, Pullman Trailmobile should indicate the sequential numbe originally assigned by the manufacturer, not the number reflecting exact order in which the vehicle is produced.; Sincerely, Frank Berndt, Chief Counsel |
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ID: aiam4227OpenMelvin Krewall, Administrator, Transportation Section, Finance Division, Oklahoma State Department of Education, 2500 North Lincoln Boulevard, Oklahoma City, OK 73105-4599; Melvin Krewall Administrator Transportation Section Finance Division Oklahoma State Department of Education 2500 North Lincoln Boulevard Oklahoma City OK 73105-4599; Dear Mr. Krewall: This responds to your August 22, 1986, letter to former Chief Counse Jeffrey Miller concerning our regulations for school bus manufacturing. You asked whether the National Highway Traffic Safety Administration (NHTSA) has certified and approved the 'Asia Smith Chassis' for school buses. You stated that you need a copy of the certification because Oklahoma requires chassis to be approved by the state Board of Education before they can be sold in Oklahoma.; I would like to begin by clarifying that the NHTSA does not certify o approve motor vehicles or motor vehicle equipment. This agency regulates motor vehicle safety under the National Traffic and Motor Vehicle Safety Act. That Act establishes a 'self-certification' process under which each manufacturer is responsible for certifying that its products meet all applicable safety standards. This process requires each manufacturer to exercise due care in selecting and conducting the mathematical calculations, computer simulations or testing that form the basis for that certification. Manufacturers certify their school buses by attaching a label to their vehicles in accordance with our certification procedures. The agency periodically tests vehicles and equipment for compliance with applicable safety standards.; A school bus manufacturer who installs a school bus body on a ne chassis (such as an Asia Smith chassis) is required by our certification regulations (49 CFR 567 and 568) to certify the completed vehicle to Federal motor vehicle safety standards for school buses. Those regulations require the chassis manufacturer to furnish information which assists the vehicle manufacturer in making that certification. When certifying its school buses, the manufacturer affirms that the vehicle, including the chassis, conforms to all applicable Federal motor vehicle safety standards, including school bus safety standards.; You indicated that Oklahoma requires school bus chassis to be approve by the state before their sale. I am concerned with this requirement because its imposition could be preempted by operation of the Vehicle Safety Act. The first sentence of section 103(d) of the Safety Act states:; >>>Whenever a Federal motor vehicle safety standard established unde this title is in effect, no State or political subdivision of a State shall have any authority either to establish, or to continue in effect, with respect to any motor vehicle or item or motor vehicle equipment any safety standard applicable to the same aspect of performance of such vehicle or item of equipment which is not identical to the Federal standards. . . .<<<; For your information, I have enclosed a copy of a Federal Registe notice issued by the agency concerning the issue of preemption and pre-sale state enforcement of safety standards (47 Fed. Reg. 884, January 7, 1982). The notice discusses NHTSA's position that Federal law preempts state requirements which proscribe the sale of equipment certified to a Federal motor vehicle safety standard unless the equipment is also approved by the State. We believe that Oklahoma's requirement for approval of school bus chassis is analogous.; As I understand Oklahoma's requirement, it imposes requirements whic have the effect of proscribing the sale of certified school buses unless their chassis are also approved by the State. Apparently, school buses manufactured with chassis lacking state approval may not be sold in Oklahoma, even though the vehicle has been certified as meeting all applicable Federal standards. In my opinion, such a requirement is preempted because it imposes burdens differing in a significant respect from the Federal regulatory scheme.; I hope this information is helpful. If you wish to further discuss th preemption issue or have any other questions, please do not hesitate to contact us.; Sincerely, Erika Z. Jones, Chief Counsel |
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ID: aiam2520OpenMr. H. Miyazawa, Director, Automotive Lighting, Engineering Department, Stanley Electric Co., Ltd., 2-9-13 Nakameguro, Meguro-Ku, Tokyo 153, Japan; Mr. H. Miyazawa Director Automotive Lighting Engineering Department Stanley Electric Co. Ltd. 2-9-13 Nakameguro Meguro-Ku Tokyo 153 Japan; Dear Mr. Miyazawa: This is in reply to your letter of February 14, 1977, concerning th symbol 'DOT' as a certification of compliance to FMVSS No. 108.; The symbol 'DOT' is permitted by the Standard to be placed on the ite of equipment in lieu of the certification requirements of Section 114 of the 'National Traffic and Motor Vehicle Safety Act of 1966,' which states, in part '...In the case of an item of motor vehicle equipment such certification may be in the form of a label or tag on such item or on the outside of a container in which such item is delivered...'; 'DOT' on the individual container does not meet the certificatio requirements. The label or tag must state that the item 'conforms to all applicable Federal motor vehicle safety standards.'; Sincerely, E. T. Driver, Director, Office of Crash Avoidance, Moto Vehicle Programs; |
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ID: aiam2170OpenMr. Edward W. Erne, Chief, Standards and Specifications Division, Bureau of Standards, Department of General Services, 2221 Forster Street, Harrisburg, PA 17125; Mr. Edward W. Erne Chief Standards and Specifications Division Bureau of Standards Department of General Services 2221 Forster Street Harrisburg PA 17125; Dear Mr. Erne: This responds to your December 12, 1975, question whether Motor Vehicl Safety Standard No. 207, *Seating Systems*, requires a restraining device for side-facing folding seats that are to (sic) used in buses and van-type vehicles.; Subsection S4.3 of Safety Standard No. 207 requires that side-facin folding seats be equipped with a restraining device, unless the seat is a 'passenger seat in a bus or a seat having a back that is adjustable only for the comfort of its occupant.'; A 'bus' is defined by Section 571.3 as a 'motor vehicle with motiv power, except a trailer, designed for carrying more than 10 persons.' Therefore, in order to come within the 'bus' exception of S4.3, the vehicle must be designed for carrying more than 10 persons. Otherwise a restraining device is required.; A 'van-type' vehicle is either a 'bus', a 'multi-purpose passenge vehicle,' or a 'truck,' depending on the number of designated seating positions. If the vehicle is designed for 10 persons or less, it is a multi-purpose passenger vehicle, not a bus, and S4.3 requires a restraining device for side-facing folding seats.; Please contact us if we can be of any further assistance. Yours truly, Richard B. Dyson, Assistant Chief Counsel |
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ID: aiam3331OpenHonorable Raphael Musto, House of Representatives, Washington, DC 20515; Honorable Raphael Musto House of Representatives Washington DC 20515; Dear Mr. Musto: This responds to your letter of August 22, 1980, concerning an inquir regarding regulations for off-road vehicles, which was referred to us by Kenneth S. Birnbaum, Director, Office of Congressional Affairs, Department of Transportation. Your constituent, Mr. Steve Schwika, asked about regulations for off-road vehicles (terrane vehicles - 6 wheel).; The National Highway Traffic Safety Administration issues both fue economy standards and Federal motor vehicle safety standards. As explained below, six-wheel terrane vehicles are not subject to fuel economy standards. However, without more detailed information concerning the vehicles, we cannot give a definitive answer as to whether Federal motor vehicle safety standards would be applicable. Nonetheless, we can provide guidelines for use in determining the status of these vehicles.; Pursuant to Title V of the Motor Vehicle Information and Cost saving Act (15 U.S.C. S2001), this agency has promulgated regulations which establish the categories of motor vehicles that are subject to fuel economy standards. The regulations (49 CFR Part 523) state that fuel economy standards are applicable only to automobiles, light trucks, and automobiles capable of off-highway travel. Under the definitions set forth at 15 U.S.C. S2001 and in the regulations, fuel economy standards are only issued for four-wheeled vehicles. A six-wheel terrane vehicle would not, therefore, be subject to fuel economy standards.; Our safety standards apply to a vehicle and its manufacturer only i the vehicle qualifies as a 'motor vehicle' under the provisions of the National Traffic and Motor Vehicle Safety Act of 1966. Section 102(3) of the Act (15 U.S.C. S1391(3)) defines 'motor vehicle' as:; >>>any vehicle driven or drawn by mechanical power manufacture primarily for use on the public streets, roads, and highways, except any vehicle operated exclusively on a rail or rails.<<<; Thus, a motor vehicle is a vehicle which the manufacturer has reason t expect will use public highways at least part of the time. We are enclosing an information sheet which gives further guidelines on which vehicles are subject to Federal motor vehicle safety standards, as well as an information sheet explaining where copies of the regulations may be obtained.; Sincerely, Frank Berndt, Chief Counsel |
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ID: aiam3761OpenMr. I. A. Wuddel, Westfalische Metall Industrie KG, Hueck & Co., Postfach 28 40, 4780 Lippstadt, Germany; Mr. I. A. Wuddel Westfalische Metall Industrie KG Hueck & Co. Postfach 28 40 4780 Lippstadt Germany; Dear Mr. Wuddel: This is in reply to your letter of September 9, 1983, to August Burget of this agency. With reference to the recent amendment to Motor Vehicle Safety Standard No. 108 permitting semi-sealed replaceable bulb headlamp systems, you have asked whether a headlamp assembly would be allowed which also incorporated a European H1 or H2 bulb, 'for an auxiliary driving beam or a front fog lamp, as our customer requests it.'; It is our understanding that the H1 bulbs are commonly used in Europea lamps as the principal lighting source, and that H2 bulbs are used in high intensity supplemental front lamps. Therefore, use of one of these bulbs in a replaceable bulb headlamp would create, in effect, a system of four headlamps. The agency recently denied a petition by Volkswagen for a four- lamp system at this time using the standardized replaceable light source (copy enclosed), because of unresolved issues. We therefore are currently unable to allow a system such as you propose with the H1 or H2 bulb in a common housing with the standardized replaceable light source, creating in effect a four- lamp headlamp system. Further, paragraph S4.1.3 of Standard No. 108, prohibits the installation of additional lighting equipment which impairs the effectiveness of lighting equipment required by Standard No. 108, and there is the distinct possibility that this could occur through incorporation of the H1 and H2 bulbs.; Use of the H1 and H2 bulbs in separate and independent units fo driving or fog lamps remains permissible, subject to regulation by the individual American States, as these items are not covered by Standard No. 108.; You may be interested to know that Volkswagen of America has recentl petitioned us for rulemaking that would allow use of the H4 bulb instead of the standardized replaceable light source in replaceable bulb headlamp systems. A decision is pending whether to grant this petition.; Sincerely, Frank Berndt, Chief Counsel |
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ID: aiam2873OpenMr. Hisakazu Murakami, Staff, Safety, Nissan Motor Company, Ltd., P.O. Box 1606, 560 Sylvan Avenue, Englewood Cliffs, NJ 07632; Mr. Hisakazu Murakami Staff Safety Nissan Motor Company Ltd. P.O. Box 1606 560 Sylvan Avenue Englewood Cliffs NJ 07632; Dear Mr. Murakami'(sic) This is in response to your letter of August 30, 1978, concerning th application of the Part 581, *Bumper Standard*, pendulum test conditions to vehicles equipped with height control systems.; Part 581 requires that a vehicle meet the protective requirements o the standard when tested at unloaded vehicle weight, that is, without occupants or cargo and with maximum capacity of all fluids necessary for operation of the vehicle. There is no language in the pendulum test requirements of the standard which would limit their applicability to only the ignition-on or ignition-off situation or to the recommended driving position for normal roadways. The vehicle must be capable of meeting the pendulum test requirements at all stable bumper heights possible at unloaded vehicle weight.; Thus, in the situations described in Question 1 and 2 of your letter in which an automatic height control system is employed, the vehicle must comply with the pendulum test requirements in both the ignition-on and ignition-off positions, i.e., positions (1) and (2). In the situation where vehicle height can be controlled manually as described in Questions 3 and 4 of your letter, the vehicle must comply with the standard at all possible settings, i.e., positions (1), (2) and (3). The presence of a label cautioning against operation of the vehicle in other than the position recommended for normal conditions would not alter the manufacturer's responsibility for compliance. In the case of National Highway Traffic Safety Administration compliance testing (Question 5), the agency will conduct its pendulum tests with the vehicle in a stable situation at unloaded vehicle weight, but may test a particular vehicle in either the ignition-on or ignition-off condition.; Sincerely, Joseph J. Levin, Jr., Chief Counsel |
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ID: aiam3274OpenMr. Thomas D. Turner, Supervisor, Engineering Services Department, Blue Bird Body Company, P.O. Box 937, Fort Valley, GA 31030; Mr. Thomas D. Turner Supervisor Engineering Services Department Blue Bird Body Company P.O. Box 937 Fort Valley GA 31030; Dear Mr. Turner: This is in reply to your letter of April 14, 1980, asking for confirmation of your interpretation of Section S4.1.4 of Motor Vehicle Safety Standard No. 108.; This section specifies requirements affecting school bus signal lamp 'when the bus entrance door is opened.' Blue Bird is designing an additional entrance door for its buses and you interpret S4.1.4 as requiring the same operational characteristics for the new door.; We confirm your interpretation that 'entrance door' means any entranc door on the school bus. Obviously the purpose of the requirement is not achieved if it is restricted to the traditional entrance door on the right front side of the bus and excludes any other entrance door.; Thank you for your interest in safety. Sincerely, Frank Berndt, Chief Counsel |
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ID: aiam1249OpenMr. John Holzer, 217-18 64th Avenue, Bayside, NY 11364; Mr. John Holzer 217-18 64th Avenue Bayside NY 11364; Dear Mr. Holzer: Thank you for your letter of September 7, 1973, requesting informatio concerning possible regulatory action involving plastic or glass gas filters.; Although we have no regulations concerning gasoline filters, the la under which our regulations are promulgated requires that where possible, our standards be based on performance rather than design requirements. This gives the automotive manufacturers maximum flexibility in conforming with the requirements and provides freedom to select whatever design he prefers in order to meet the requirements of the standard.; Our current fuel system requirements are contained in Federal Moto Vehicle Safety Standard No. 301, Fuel Tanks, Fuel Tank Filler Pipes and Fuel Tank Connections, which was effective January 1, 1968. A copy of this standard is enclosed for your information. We have recently issued an amendment to the standard and a proposed amendment which are intended to substantially upgrade fuel systems of motor vehicles between September 1, 1975 and September 1, 1977. Copies of these rulemaking actions are enclosed for your information (38 F.R. 22397 and 22417).; Motor vehicle manufacturers are free to choose the components an designs which they consider most appropriate to their performance requirements. It is quite possible that certain components cannot be used as original equipment because of periodic regulatory actions, for example, a manufacturer may consider a glass fuel filter hazardous when he is attempting the preservation of fuel system integrity incidental to a 20 mile-per-hour, fixed barrier collision.; We would suggest that contact be made with the automotive manufacturer and original equipment manufacturers for a more complete answer to your question.; If we can be of any further assistance, please do not hesitate t contact us.; Sincerely, Robert L. Carter, Associate Administrator, Motor Vehicl Programs; |
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ID: aiam3624OpenMr. F. E. Bettridge, Board Chairman, Middlekauff, Inc., 1615 Ketcham Avenue, Toledo, OH 43608; Mr. F. E. Bettridge Board Chairman Middlekauff Inc. 1615 Ketcham Avenue Toledo OH 43608; Dear Mr. Bettridge: This is in reply to your letters of September 27 and October 7, 1982 concerning your wish for a temporary exemption from Standard No. 301.; In our letter of August 12, 1982, we informed you that the statemen which 49 CFR Part 568 requires an incomplete vehicle manufacturer to furnish with the vehicle affords a basis for certification without the necessity of testing. We asked you which of the statements had been provided you. Your subsequent correspondence with us does not answer this question. You refer to a print furnished you by AM General Corporation after August 12 which, with your engineering studies, leads you to believe that you may comply, but the print is extraneous to the Part 568 statement.; Therefore, we would still like to know whether AM General has provide you with a statement of specific conditions of final manufacture under which the completed vehicle will conform with Standard No. 301, or, alternatively, with a statement that the vehicle will conform if no alterations are made in certain specified components of the incomplete vehicle. Perhaps you could send us a copy of that portion of the Part 568 statement pertaining to Standard No. 301.; We shall consider your petition further when we have this information. Sincerely, Frank Berndt, 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.