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: aiam2927OpenWilliam Shapiro, P.E., Manager, Regulatory Affairs, Volvo of America Corporation, Rockleigh, NJ 07647; William Shapiro P.E. Manager Regulatory Affairs Volvo of America Corporation Rockleigh NJ 07647; Dear Mr. Shapiro: Please excuse the delay in responding to your letter of October 25 1978. You asked whether a webbing guide you are planning for the rear seat belt in station wagon vehicles would have to comply with the strength requirements of Safety Standard No. 210, *Seat Belt Assembly Anchorages*.; The agency has examined the drawings included in your letter an discussed this new webbing guide with Volvo engineers. We have concluded that the webbing guide would not qualify as an 'anchorage' and, therefore, would not have to comply with the Standard 210 requirements for anchorages. The standard defines 'anchorage' as a device that transfers seat belt assembly loads to the vehicle structure. Your proposed webbing guide is not intended to transfer loads to the vehicle structure, and will only be added to increase the comfort of the assembly. As you indicated, the device marked 'B' on your drawings would qualify as an anchorage and would have to meet the strength requirements of the standard.; Sincerely, Joseph J. Levin, Jr., Chief Counsel |
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ID: aiam1608OpenMr. C. J. Baker, Research & Development Engineer, Peerless Division, Royal Industries, P.O. Box 447, Tualatin, OR 97062; Mr. C. J. Baker Research & Development Engineer Peerless Division Royal Industries P.O. Box 447 Tualatin OR 97062; Dear Mr. Baker: This responds to your August 28, 1974, question whether a 'logging pol trailer', which consists of a beam to which an axle-mounted bolster can be clamped at different points to accomodate (sic) different log lengths, qualifies as a heavy hauler trailer as that term is defined in Standard No. 121, *Air brake systems*:; >>>'Heavy hauler trailer' means a trailer with one or more of th following characteristics:; (1) Its brake lines are designed to adapt to separation or extension o the vehicle frame, or; (2) Its body consists only of a platform whose primary cargo-carryin surface is not more than 40 inches above the ground in an unloaded condition, except that it may include sides that are designed to be easily removable and a permanent 'front-end structure' as that term is used in S 393.106 of this title.<<<; The logging pole trailer you describe is a heavy hauler trailer, and a such, Standard No. 121 does not apply to this trailer until September 1, 1976. The beam or 'reach', together with the bolster, constitutes the frame of the trailer, and the brake lines are designed to adapt to extension of the bolster element along the beam.; This arrangement differs from the standard highway van which has one-piece frame with an adjustable tandem axle. The purpose of this sliding arrangement is unrelated to an extension of the frame itself to accomodate (sic) the transportation of heavy or oversize loads.; Yours truly, Richard B. Dyson, Acting Chief Counsel |
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ID: aiam3635OpenMr. Kenji Tashima, Project Manager, Mazda (North America), Inc., 23777 Greenfield Road, Suite 462, Southfield, MI 48075; Mr. Kenji Tashima Project Manager Mazda (North America) Inc. 23777 Greenfield Road Suite 462 Southfield MI 48075; Dear Mr. Tashima: This responds to your recent letter asking whether various vehicl seating designs being considered by your company would qualify as auxiliary seating positions and not be subject to the Federal motor vehicle safety standards. These seats would be installed in extended-cab pick-up trucks behind the driver's and front passenger's seats and would include storage space beneath the seating accommodation.; A seating accommodation is subject to the vehicle safety standard (e.g., Standards Nos. 207, 208) if it qualifies as a 'designated seating position'. That term is defined in 49 CFR 571.3 as:; >>>'any plan view location capable of accommodating a person at leas as large as a 5th percentile adult female, if the overall seat configuration and design is such that the position is likely to be used as a seating position while the vehicle is in motion, except for auxiliary seating accommodations such as temporary or folding jump seats....'<<<; In our opinion, most of the seat designs included in your illustration would be considered to be designated seating positions. We would not consider the seats to be 'auxiliary seating accommodations' since, as you stated in meeting with us, they would be present as a cushioned seat a majority of the time, i.e., without having to fold the seats down or move them around as is necessary with a temporary jump seat. The fact that the seats are not 'auxiliary' is further evidenced to a certain extent by the fact that the cab of the pick-up trucks would be extended to accommodate the seats so that four persons could ride inside the vehicle. You do not suggest that the cab would be extended for the primary purpose of providing the small amount of storage space that would be beneath these seats.; In your illustrations, seat designs A, B, C, F, G, and H have a overall seat configuration such that the position is likely to be used as a seating position while the vehicle is in motion. Your designs D and E may be somewhat less likely to be used as seats since design D does not have a cushion (just a board) and design E does not have a seat back. If these two designs were combined, i.e., no seat back and no seat cushion, the agency would consider the positions to be auxiliary seating positions. It is possible that either design D or E alone might also be considered to be an auxiliary seating position, depending on the agency's assessment of the seat together with the total passenger compartment design. I would like to emphasize, however, that it is the responsibility of the manufacturer to determine whether or not its vehicles are in compliance with all applicable safety standards and to certify that compliance. Therefore, your company would have to make its own determination concerning whether any of these designs would qualify as designated seating positions. The agency can only offer its opinion based on the information supplied in your letter. The agency would make its own final determination only during an enforcement investigation involving a certified vehicle.; You also asked the following general questions regarding all of th designs illustrated in your letter: are seat belts required, is seat size a factor in determining whether a seat is auxiliary, and is there a distinction in the determinations if a bench seat is used instead of two separate cushions? As mentioned earlier, seat belts are required if a particular accommodation is determined to be a designated seating position. Seat size is a factor in determining whether a particular position is a designated seating position to the extent that the definition of that term specifies, as a threshold, a space capable of accommodating at least a 5th percentile adult female (your letter notes that all your designs are capable of accommodating a 5th percentile adult female). Whether or not a particular position is designed as a bench seat or as separate cushions is generally irrelevant to the determination of whether the seat qualifies as a designated seating position.; I hope this has been responsive to your inquiry. Please contact Hug Oates of my staff if you have any further questions (202) 426-2992.; Sincerely, Frank Berndt, Chief Counsel |
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ID: aiam1258OpenMrs. Deborah D. Richards, Chairman of the Board, Action for Child Transportation Safety, 400 Central Park West, 2R, New York, NY 10025; Mrs. Deborah D. Richards Chairman of the Board Action for Child Transportation Safety 400 Central Park West 2R New York NY 10025; Dear Mrs. Richards: Thank you for your letter of August 31, 1973, concerning you organization and its support for improved child restraint and school bus safety standards.; We hope to issue notices of proposed rule making on child restrain systems and on the strength of structural joints of school bodies this fall. We are also actively involved in rule making action in the bus passenger seating and crash protection area.; Concerning Standard No 17, this is not a standard where full an immediate compliance by states is possible. A reasonable amount of time, which will vary from state to state, will be allowed for compliance. The National Highway Traffic Safety Administration does, however, expect all states to reach substantial fulfillment of the requirements of this standard by the fall of 1977. According to our data, 16 states indicate complete compliance as of May 1973.; We are enclosing a copy of our May 1973 School Bus Task Force Repor which outlines recommendations for work in the school bus area. This may be of use to you as a resource for your newsletter.; When our dynamic test amendment to the child restraint standard i published as a final rule, we plan to revise our consumer information booklet entitled 'What to Buy in Child Restraint Systems.' We hope this publication will greatly improve usage of the proper type restraint by more and more children.; We appreciate your efforts in promoting safety for children who ar passengers in motor vehicles.; Sincerely, James B. Gregory, Administrator |
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ID: aiam3265OpenMr. Robert A. Eddy, Manager, Quality Assurance, McCreary Tire & Rubber Company, Indiana, PA 15701; Mr. Robert A. Eddy Manager Quality Assurance McCreary Tire & Rubber Company Indiana PA 15701; Dear Mr. Eddy: This is in response to your letter of March 7, 1980, asking whethe ASTM E501 and E524 tires must be graded in accordance with the Uniform Tire Quality Grading (UTQG) Standards (49 CFR 575.104). You state that these tires are manufactured in limited quantities as standards for traction testing and are not manufactured for general highway use. It is the National Highway Traffic Safety Administration's understanding that these tires are used only on a test trailer designed for use in skid testing.; The UTQG regulation applies to new pneumatic tires for use on passenge cars (49 CFR 575.104(c)(1)). Thus, ASTM E501 and E524, which are manufactured solely for use on a traction test trailer, would not fall within the application of the UTQG Standards.; Sincerely, Frank Berndt, Chief Counsel |
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ID: aiam2024OpenHonorable Bob Packwood, United States Senate, Washington, DC 20510; Honorable Bob Packwood United States Senate Washington DC 20510; Dear Senator Packwood: Thank you for your letter of August 8, 1975, forwarding a copy of letter to me from Mr. William G. White, President of Consolidated Freightways Corporation, and asking for early consideration of Mr. White's request. In that letter, Mr. White asks that the National Highway Traffic Safety Administration require reports from all truck operators and antilock system manufacturers on any malfunction they experience with antilock systems.; I have given full consideration to the important matter of collectin sufficient data on the reliability of antilock systems used on production vehicles, and I have responded to Mr. White with my conclusions. A copy of that response is enclosed to provide you with a complete explanation of my decision.; Sincerely, William T. Coleman, Jr. |
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ID: aiam0019OpenPenn Affiliates, Inc., American Seat Belt Council, Inc., 271 North Avenue, New Rochelle, NY 10801; Penn Affiliates Inc. American Seat Belt Council Inc. 271 North Avenue New Rochelle NY 10801; Gentlemen: This is in reply to your letter of February 16, 1967. Motor Vehicle Safety *Standard No. 209* applies to seat belt assemblie manufactured after February 28, 1967, for use in passenger cars, multipurpose passenger vehicles, trucks, and buses. Since Motor Vehicle Safety Standard No. 208, which provides that a Type 1 or Type 2 seat belt assembly that conforms to Motor Vehicle Safety Standard No. 209 shall be installed in each passenger car seat position, has an effective date of January 1, 1968, until that date seat belt assemblies installed in passenger cars need not conform to Standard No. 209 unless the seat belt assemblies have been manufactured after February 28, 1967.; Please do not hesitate to call upon us if we can be of further servic to you.; Sincerely, William Haddon, Jr., M.D., Administrator |
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ID: aiam4959OpenMr. Paul N. Wagner President Bornemann Products Incorporated 402 Industrial Drive P.O. Box 427 Bremen, IN 46506; Mr. Paul N. Wagner President Bornemann Products Incorporated 402 Industrial Drive P.O. Box 427 Bremen IN 46506; "Dear Mr. Wagner: This responds to your letter seeking furthe information about the extension of the dynamic testing requirements in Standard No. 208, Occupant Crash Protection to light trucks and vans. You indicated that you were particularly interested in the application of the dynamic testing requirements to vehicles manufactured in more than one stage. Your letter stated that throughout 1991 your company was repeatedly led to believe there would be no delay of the September 1, 1991 effective date for the application of the dynamic testing requirements to light trucks and vans. Your letter also indicated that, after proceeding with testing to ensure that your company's van conversions would comply with the dynamic testing requirements, you found additional complications hampering your testing efforts. In response to these complications, your company filed a petition asking that the applicability of the dynamic testing requirements to light trucks and vans manufactured in more than one stage be delayed from the scheduled September 1, 1991 date until April 1, 1992. NHTSA received your petition on August 29, 1991. This petition was rejected as untimely and you were notified of the rejection in an October 10, 1991 letter from Mr. Barry Felrice, our Associate Administrator for Rulemaking. Your company proceeded with further testing after you learned that NHTSA had not accepted your petition, and have been able to certify that your conversion vans comply with the dynamic testing requirements. Your letter estimated that the total cost of the research and testing performed by your company to certify compliance with the dynamic testing requirements was nearly $200,000. Then, on January 21, 1992, your company received a memorandum from the trade group Recreational Vehicle Industry Association (RVIA), announcing that representatives of RVIA had met with representatives of this agency on January 14, 1992. You believed that the RVIA memorandum 'indicates a delay of the September 1, 1991 effective date for the dynamic testing requirements is on the horizon.' Your letter suggested that there is now confusion among van converters and other multistage manufacturers about the status of the dynamic testing requirements for vehicles manufactured in more than one stage. You asked us to state whether a delay in the effective date for the dynamic testing requirements as applied to multistage vehicles is now being considered by the agency. The answer is no. There was a meeting between representatives of this agency and the RVIA on January 14, 1992. From our perspective, the meeting was informative and constructive, and provided us with further insights into the efforts that were needed for van converters to ensure that their vans complied with the new dynamic testing requirements. We hope to maintain such dialogues with RVIA and any other interested multistage manufacturers. However, our January 14, 1992 meeting did not change some facts. First, the dynamic testing requirements took effect for light trucks and vans on September 1, 1991, including light trucks and vans manufactured in more than one stage. This means that each light truck and van manufactured on or after September 1, 1991 had to be certified by its manufacturer as complying with the dynamic testing requirements. Second, any member of the public can petition the agency to modify any of its standards, including the dynamic testing requirements as they apply generally to light trucks and vans manufactured in more than one stage. If RVIA should submit a petition to modify the dynamic testing requirements, as it suggested it would in the memorandum you received, NHTSA would consider that petition according to the same procedures followed in the case of your company's petition on this subject or any other petition from the public. I hope this information is helpful. If you have any further concerns or questions, please let me know. Sincerely, Paul Jackson Rice Chief Counsel"; |
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ID: aiam2474OpenHonorable Albert H. Quie, House of Representatives, Washington, D.C. 20515; Honorable Albert H. Quie House of Representatives Washington D.C. 20515; Dear Mr. Quie: This is in reply to your letter of December 15, 1976, regarding complaint by Mr. Russ Fink, that tires marked within a certain size classification are not uniform.; Mr. Fink's letter does not report any actual tire dimensions and doe not fully explain the age of his tires, the amount of treadwear, the type of tread pattern, inflation pressures, and the width of the rims when he was making his measurements. All of these factors have an effect on tire size matching, and must be considered in making dimensional comparisons.; Contrary to Mr. Fink's claim, tire manufacturing is carefull controlled to meed rigid dimensional requirements. These requirements are a part of our Federal Motor Vehicle Safety Standards (FMVSS) No. 109 for new passenger car tires, No. 119 for other new motor vehicle tires, and No. 117 for retreaded passenger car tires. A copy of each is enclosed . Every effort is made in our standards enforcement program to assure that manufacturers and retreaders comply with the specified dimensional requirements.; Referring to the tables in Appendix AS of FMVSS No. 109, Mr. Fink ca see that there are differences is specifications for the three tires he mentions:; Tire Rim Max. Load Section Min. Size Size Width at 24 psi Width Facto H78-15 6'' 1450 8.55 36.50 7.60-15 5-1/2'' 1450 7.90 36.05 8.55-15 6'' 1510 8.45 36.57; In purchasing new or retreaded tires from a tire dealer, consumers ar entitled to dimensions held within specified tolerances, and when tires are found to exceed these tolerances we would appreciate being notified so that we may initiate investigation.; Sincerely, John W. Snow, Administrator |
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ID: aiam0449OpenMr. Paul H. Lawrenz, American Motors Corporation, 14250 Plymouth Road, Detroit, MI, 48232; Mr. Paul H. Lawrenz American Motors Corporation 14250 Plymouth Road Detroit MI 48232; Dear Mr. Lawrenz: This is in reply to your letter of September 21, 1971, to Mr. Lewis C Owen of this Office concerning an interpretation on the visibility requirements in FMVSS No. 108 as referenced in FMVSS No. 215.; Paragraph S4.3.1.1 of FMVSS No. 108 requires that the lamps be visibl at the extreme photometric test angles or as otherwise specified in the applicable SAE Standards. This paragraph does not require photometric tests at these extreme angles.; Sincerely, E. T. Driver, Director, Office of Operating Systems, Moto Vehicle Programs; |
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.