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: aiam5076OpenMark W. Stevens Chairman SeatMore 1091 Industrial Rd. Suite 240 San Carlos, CA 94070; Mark W. Stevens Chairman SeatMore 1091 Industrial Rd. Suite 240 San Carlos CA 94070; "Dear Mr. Stevens: This responds to your letter of October 2, 199 requesting information on standards applicable to an 'after market 3rd rear facing seat for the Ford Taurus and Mercury Sable station wagons 1986-1993.' During an October 20, 1992 phone conversation with Mary Versailles of my staff you explained that in most instances these seats are sold for installation in used vehicles, by either the owner or by a dealer or repair business. You also stated that the seat might be installed by a dealer prior to the vehicle's sale. Your three questions and the answer to each follows. Before I address the substance of your letter, I note that your letter requested that the product information enclosed with your letter be treated as confidential. Your request for confidentiality was denied in an October 27, 1992 letter signed by Kathleen DeMeter, our Assistant Chief Counsel for General Law. Accordingly, the product information enclosed with your letter has been placed in NHTSA's public docket, along with your letter and this reply. 1. Does the aftermarket 3rd rear facing station wagon system have to be tested in compliance with FMVSS 207, 209, & 210? The National Traffic and Motor Vehicle Safety Act (the Safety Act, 15 U.S.C. 1381 et seq.) authorizes this agency to issue Federal motor vehicle safety standards applicable to new motor vehicles and new items of motor vehicle equipment. Section 108(a)(1)(A) of the Safety Act (15 U.S.C. 1397(a)(1)(A)) prohibits any person from manufacturing, introducing into commerce, selling, or importing any new motor vehicle or item of motor vehicle equipment unless the vehicle or equipment item is in conformity with all applicable safety standards. NHTSA, however, does not approve motor vehicles or motor vehicle equipment, nor do we endorse any commercial products. Instead, the Safety Act establishes a 'self-certification' process under which each manufacturer is responsible for certifying that its products meet all applicable safety standards. NHTSA has exercised its authority to establish five safety standards which could be applicable to a 3rd rear facing vehicle seat: Standard No. 207, Seating Systems, Standard No. 208, Occupant Crash Protection, Standard No. 209, Seat Belt Assemblies, Standard No. 210, Seat Belt Assembly Anchorages, and Standard No. 302, Flammability of Interior Materials. Standard No. 209 sets forth strength, elongation, webbing width, durability, and other requirements for seat belt assemblies. This standard applies to all seat belt assemblies for use in motor vehicles, regardless of whether the belts are installed as original equipment in a motor vehicle or sold as replacements. Hence, any seat belts installed on the 3rd rear facing seat have to be certified as complying with Standard No. 209. The remaining four standards apply only to new vehicles. If the 3rd rear facing seat were installed before the vehicle's first purchase for purposes other than resale, the vehicle would have to be certified as complying with all applicable standards, including these four, with the 3rd rear facing seat installed. Standard No. 207 establishes strength and other performance requirements for vehicle seats. Standard No. 208 sets forth requirements for occupant protection at the various seating positions in vehicles. Standard No. 210 establishes strength and location requirements for seat belt anchorages. Finally, Standard No. 302 specifies burn resistance requirements for materials used in motor vehicles, specifically including seat cushions, seat backs, and seat belts. After a vehicle's first purchase for purposes other than resale, i.e., the first retail sale of the vehicle, the only provision in Federal law that affects a vehicle's continuing compliance with an applicable safety standard is set forth in section 108(a)(2)(A) of the Safety Act (15 U.S.C. 1397(a)(2)(A)). That section provides that: No manufacturer, distributor, dealer, or motor vehicle repair business shall knowingly render inoperative, in whole or in part, any device or element of design installed on or in a motor vehicle ... in compliance with an applicable Federal motor vehicle safety standard. Any violation of this 'render inoperative' prohibition would subject the violator to a potential civil penalty of up to $1,000 for each violation. Please note that the 'render inoperative' prohibition does not require manufacturers, distributors, dealers, and repair businesses to certify that vehicles continue to comply with the safety standards after any aftermarket modifications are made. Instead, 'render inoperative' prohibits those entities from performing aftermarket modifications that they know or should know will result in the vehicle no longer complying with the safety standards. Please note also that the 'render inoperative' prohibition does not apply to modifications vehicle owners make to their own vehicles. Thus, Federal law would not apply in situations where individual vehicle owners install your company's 3rd seat in their own vehicles, even if the installation were to result in the vehicle no longer complying with the safety standards. However, individual States have the authority to regulate modifications that individual vehicle owners may make to their own vehicles. 2. The seat belt anchorages are Ford factory anchorages built into the car at the factory and designed for the Ford factory 3rd seat and seat belts. We will be using the same anchorages with aftermarket seat belts already in compliance. Is a test required for this system? As noted above, if these 3rd seats are installed in a vehicle prior to the vehicle's first sale for purposes other than resale, the vehicle must be certified as complying with all applicable safety standards with the 3rd seat installed. NHTSA's position on what steps manufacturers must take before certifying that their vehicles or equipment comply with applicable safety standards has been often stated and applies with equal force in your situation. The compliance test procedures set forth in the safety standards must be followed by this agency during our compliance testing. With respect to your company's 3rd seats, this means that NHTSA's compliance testing for the vehicle would be conducted using the test procedures set forth in the relevant safety standard or standards. Manufacturers certifying compliance with the safety standards are not required to follow exactly the compliance test procedures set forth in the applicable standard. In fact, manufacturers are not required to conduct any actual testing before certifying that their products comply with applicable safety standards. However, to avoid liability for civil penalties if the vehicle were determined not to comply with a safety standard, the Safety Act requires the certifying manufacturer to exercise 'due care' to assure compliance and in making its certification. It may be simplest for the manufacturer to establish that it exercised 'due care' if the manufacturer has conducted testing that strictly followed the compliance test procedures set forth in the standard. However, 'due care' might also be shown by using modified test procedures, engineering analyses, computer simulations, and the like. Thus, the entity that installs your company's 3rd seat in a vehicle prior to the vehicle's first sale will have to decide for itself, in the first instance, what information it needs to make its certification in the exercise of 'due care.' If the 3rd seat were installed after the first purchase of the vehicle in good faith for purposes other than resale, no certification would be required. Instead, any manufacturer, distributor, dealer, or repair shop that performed the installation would have to ensure that the installation did not 'render inoperative' compliance with any applicable safety standard. Actual testing is not required to avoid violating the 'render inoperative' prohibition. Instead, your company could carefully examine your product and the proposed installation instructions and compare those with the requirements of the safety standards, to determine if installing your product in accordance with your instructions would result in the vehicle no longer complying with the standards. 3. If testing is required, must they be specifically Static Tested or Dynamic Crash Tested? Testing is required only in agency compliance testing, as explained above. Agency testing must be conducted in accordance with the test procedures specified in the applicable standard. I note, however, that the dynamic crash testing requirement in Standard No. 208 applies only to the front outboard seating positions. For your information, I have enclosed a sheet for new manufacturers that identifies the basic requirements of our standards and regulations, as well as how to get copies of those standards and regulations. 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 Enclosure"; |
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ID: aiam1035OpenMr. Donald W. Taylor, Engineering Liaison Representative, Volvo of America Corporation, Rockleigh, NJ, 07647; Mr. Donald W. Taylor Engineering Liaison Representative Volvo of America Corporation Rockleigh NJ 07647; Dear Mr. Taylor: This is in reply to your letter of February 9, 1973, regarding th application of Motor Vehicle Safety Standard No. 302, 'Flammability of Interior Materials'. You ask whether both the face and the under-surfaces of a single or composite material must meet the burn- rate requirement of Paragraph S4.3, and whether it is necessary to subject both surfaces to the flammability test in Paragraph S5.; Under Paragraph S5.2.2 of the standard, test specimens for eac component are to be tested 'so as to provide the most adverse results'. This means that the relevant test result is the most adverse one achieved in any horizontal orientation, either upward- or downward-facing. Accordingly, while every surface of a test specimen must meet the burn-rate requirement, the way you determine which positioning of the test specimen produces the most adverse results is within your own discretion.; Yours truly, Richard B. Dyson, Assistant Chief Counsel |
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ID: aiam3008OpenMr. Teruo Maeda, General Manager, Nissan Motor Co., Ltd., Engineering Office of North America, P.O. Box 1606, 560 Sylvan Avenue, Englewood Cliffs, NJ 07632; Mr. Teruo Maeda General Manager Nissan Motor Co. Ltd. Engineering Office of North America P.O. Box 1606 560 Sylvan Avenue Englewood Cliffs NJ 07632; Dear Mr. Maeda: This is in response to your letter of April 19, 1979, asking whether tie down hook located beneath a vehicle between the rear main body and the rear bumper is considered a vehicle exterior surface for purposes of section 581.5(c)(10) of the Part 581 Bumper Standard (49 CFR 581.5(c)(10)). You state that this component may experience some paint separation on contact with the vehicle bumper face bar during pendulum and barrier impact testing.; >>>Section 581.5(c)(10) provides that, 'For vehicles manufactured on or after September 1, 1979, the exterio surfaces, except the bumper face bar, shall have no separations of surface materials, paint, polymeric coatings, or other materials from the surface to which they are bonded ...'<<<; when subjected to the specified pendulum and barrier tests. A component located on the vehicle underbody behind the bumper face ba is not an exterior surface for purposes of section 581.5(c)(10). For this reason, the tie down hook you describe would not be subject to the requirements of that section.; Sincerely, Frank Berndt, Acting Chief Counsel |
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ID: aiam4237OpenThe Honorable Slade Gorton, United States Senate, Washington, DC 20510; The Honorable Slade Gorton United States Senate Washington DC 20510; Dear Senator Gorton: Thank you for your November 3, 1986, letter on behalf of you constituent, Mrs. Laurel Kuther of Clarkston, who asks that safety belts be required on school buses. Your letter has been referred to my office for reply, since the National Highway Traffic Safety Administration (NHTSA) is responsible for administering Federal programs relating to school bus safety.; I appreciate this opportunity to respond to your concerns. As explaine below, NHTSA does not require large school buses to have safety belts for passengers because we require those buses to provide an alternate form of passenger crash protection. Our safety standards are directed at improving the interior of large school buses so that passengers will be provided adequate crash protection even if safety belts are not used.; I would like to begin with some background information on our schoo bus regulations. NHTSA is responsible for developing safety standards applicable to all new motor vehicles, including school buses. In 1977, we issued a set of motor vehicle safety standards for various aspects of school bus safety. Included in that set is Federal Motor Vehicle Safety Standard No. 222, *School Bus Passenger Seating and Crash Protection*. Standard No. 222 requires large school buses--i.e., those with gross vehicle weight ratings over 10,000 pounds--to provide passenger crash protection through a concept called 'compartmentalization.' Compartmentalization requires that the interior of large buses be improved so that children are protected regardless of whether they have fastened a safety belt. The seating improvements include higher and stronger seat backs, additional seat padding, and better seat spacing and performance.; Our safety standards require a safety belt for the school bus drive since the driver's position is not compartmentalized. We also require safety belts for passengers in smaller school buses because those buses experience greater crash forces than do larger buses and the additional restraint system is needed to provide adequate crash protection for passengers.; However, because large school buses already offer substantia protection to passengers and a Federal endorsement for safety belts in those vehicles is unnecessary. In addition to meeting Federal school bus safety standards, large school buses are very safe vehicles because of their size and weight, the training and experience of their drivers and the extra care that other road users employ in the vicinity of school buses. NHTSA does not prevent States and local jurisdictions that wish to order safety belts on their own large buses from doing so. Such a decision is a matter for the officials of the particular State or local jurisdiction, who are best able to assess their own pupil transportation needs.; A June 1985 NHTSA publication entitled, 'Safety Belts in School Buses, discusses many of the issues relating to safety belts in large school buses. I have enclosed a copy of the report for your information.; I hope you have found this information to be helpful. If you or you constituent have any further questions, please do not hesitate to contact me.; Sincerely, Erika Z. Jones, Chief Counsel |
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ID: aiam1465OpenMr. Robert E. Langdon III, 2511 West 7th Street, Los Angeles, California 90057; Mr. Robert E. Langdon III 2511 West 7th Street Los Angeles California 90057; Dear Mr. Langdon: This is in reply to your letter of April 12, 1974, asking whethe retreaded tires are required by Motor Vehicle Safety Standard No. 117 to have either a ribbed tread pattern or treadwear indicators.; Standard No. 117 does not have requirements for tread pattern design and thus retreaded tires need not have a ribbed tread design. Each retreaded tire must, however, in accordance with S5.1.1(b) of Standard No. 117, incorporate a treadwear indicator that will provide a visual indication that the tire has worn to a tread depth of 1/16 inch.; Yours truly, Richard B. Dyson, Assistant Chief Counsel |
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ID: aiam3458OpenMr. W. D. Smith, Acting Chief of Staff, United States Marine Corps, Marine Corps Logistics Base, Barstow, CA 92311; Mr. W. D. Smith Acting Chief of Staff United States Marine Corps Marine Corps Logistics Base Barstow CA 92311; Dear Mr. Smith: This responds to questions raised in your June 23, 1981 letter whic was referred to us by Mr. Zemaitis of our regional office. In your letter, you ask for exemption of your vehicles from several Highway Safety Program Standards relating to school buses.; As Mr. Zemaitis indicated, the Highway Safety Program Standards ar applied by the States. If the States deem it appropriate to provide exemptions in the limited type of circumstances described in General Shaffer's May 15, 1981 letter to the California Highway Patrol, they are permitted to do so. Accordingly, I suggest that the Marine Corps again contact the appropriate State officials for the exemption you desire.; The National Highway Traffic Safety Administration has always exempte military vehicles from its Federal Motor Vehicle Safety Standards. This exemption is codified in Volume 49 of the Code of Federal Regulations at Part 571.7(c). You may want to point this out to California officials and ask them to adopt a similar exemption policy with respect to your vehicles.; Sincerely, Frank Berndt, Chief Counsel |
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ID: aiam4667OpenMr. Don James Contracts Stone Bennett Corporation l4l9 Upfield Drive Carrollton, Texas 75006; Mr. Don James Contracts Stone Bennett Corporation l4l9 Upfield Drive Carrollton Texas 75006; "Dear Mr. James: This responds to your letter concerning Federal Moto Vehicle Safety Standard No. l02, Transmission Shift Lever Sequence, Starter Interlock, and Transmission Braking Effect. You asked about the standard's display identification requirements for automatic transmission vehicles without a gear shift lever park position. Your questions are addressed below. 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 and equipment meet all applicable requirements. The following represents our opinion based on the facts provided in your letter. Standard No. l02 sets forth the following display identification requirements for automatic transmission vehicles without a gear shift park position: S3.l.4 Identification of shift lever positions. . . . S3.l.4.2 Except as specified in S3.l.4.3, if the transmission shift lever sequence does not include a park position, identification of shift lever positions, including the positions in relation to each other and the position selected, shall be displayed in view of the driver at all times when a driver is present in the driver's seating position. S3.l.4.3 Such information need not be displayed when the ignition is in a position that is used only to start the vehicle. You asked about several similar designs for shift control consoles. In addition to including a mechanism for shifting the transmission (push buttons or toggle levers), the consoles incorporate a display which lists the particular gear position which has been selected, e.g., 'R' for reverse. No other gear positions are shown. In at least some of the designs, the display is an electronic one. You asked about the 'acceptability' of providing a label indicating the gear position sequence on the body of the shift control console, e.g., '1 2 D N R.' Drawings provided with your letter indicate that the label would be provided directly adjacent to the gear position display. As indicated above, section S3.l.4.2 requires identification of shift lever positions, including the positions in relation to each other and the position selected, to be displayed in view of the driver. While your designs do identify the gear position selected, they do not, in the absence of an added label, identify the shift lever positions in relation to each other. The additional label would, however, provide such information. Section S3.l.4.2 also requires that the specified information be displayed in view of the driver at all times when a driver is present in the driver's seating position (except when the ignition is in a position that is used only to start the vehicle). The times when display is required includes situations in which the ignition is 'off.' Since your designs use electronic technology to identify the gear position selected, a vehicle equipped with your design might not meet this requirement, at least in the absence of a device which activates the display whenever a driver is present. It is our understanding that 'permanent' display is not possible with electronic technology, due to battery drain. However, if the gear position display is turned off with the ignition (the most obvious means of avoiding battery drain), this requirement would not be met. This is because the display would not function when a driver is in the driver's seating position (before leaving the vehicle or upon entering the vehicle at a later time) while the ignition is 'off.' As you are aware, NHTSA has proposed new requirements for the purpose of facilitating the use of electronic technology. See 55 FR l226, January l2, l990. If amendments are adopted based on that proposal, the analysis presented above could change. Sincerely, Paul Jackson Rice Chief Counsel Enclosure"; |
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ID: aiam2160OpenMr. Jack Gromer, Timpte, Inc., 5990 N. Washington Street, Denver, CO 80216; Mr. Jack Gromer Timpte Inc. 5990 N. Washington Street Denver CO 80216; Dear Mr. Gromer: This responds to Timpte's December 10, 1975, question whethe modification of a certified trailer prior to retail sale constitutes the manufacture of a vehicle subject to applicable safety standards such as Standard No. 121, *Air Brake Systems*.; The answer to your question is no. From your description, it appear that the proposed modification would be an alteration of a certified vehicle subject to S 567.7 of NHTSA certification regulations (49 CFR S 567.7) (copy enclosed). Under that section, conformity of the vehicle as altered need only be to standards in effect at the time the originally certified trailer was manufactured.; Sincerely, Richard B. Dyson, Assistant Chief Counsel |
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ID: aiam2530OpenMr. W. G. Milby, Manager, Engineering Services, Blue Bird Body Company, P.O. Box 937, Fort Valley, GA 31030; Mr. W. G. Milby Manager Engineering Services Blue Bird Body Company P.O. Box 937 Fort Valley GA 31030; Dear Mr. Milby: This responds to your February 9, 1977, letter asking whether 1 described intersections of bus body components qualify as 'body panel joints' subject to the requirements of Standard No. 221, *School Bus Body Joint Strength*.; The terms which establish the applicability of the requirements of th standard to a particular section of a school bus body are defined in S4 of the standard. Read together, they establish the following test. If the edge of a surface component (body panel) that encloses occupant space comes into contact or close proximity with any other body component, the requirements of S5 apply, unless the area in question is designed for ventilation or another functional purpose or is a door, window or maintenance access panel. Applying this test to the 10 intersections of bus body components you describe, it appears that none of them are required to comply with the standard.; The joints numbered 1 through 4 on page 1 of your letter refer t hanger straps, panels and pads involved in the installation of overhead storage racks. These items of equipment are not considered to have a function in enclosing occupant compartment space and, therefore, are excluded from the standard's requirements.; The exterior roof luggage rack described in paragraphs 5 and 6 is no considered to have a function in enclosing occupant space and, therefore, is not considered a body component for purposes of the requirements. For purposes of testing the complex joints to which the rack is fastened, it should be modified as necessary to prevent it from affecting testing of the underlying joint.; The NHTSA agrees that the joints described in paragraphs 1 through 4 o page 2 of your letter, relating to the installation of air conditioning units, involve the type of ventilation space that is not subject to the requirements for joint strength.; Sincerely, Frank Berndt, Acting Chief Counsel |
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ID: aiam2863OpenMr. Alberto Negro, Fiat, Research & Development - U.S.A. Branch, Parklane Towers West Suite 1210, Dearborn, MI 48126; Mr. Alberto Negro Fiat Research & Development - U.S.A. Branch Parklane Towers West Suite 1210 Dearborn MI 48126; Dear Mr. Negro: This responds to your June 16, 1978, letter asking whether manufacturer is permitted to list on the certification label required by Part 567, *Certification*, the gross axle weight rating (GAWR) in kilograms as well as pounds. The National Highway Traffic Safety Administration has permitted the use of kilograms on the certification label as long as the label continues to list the GAWR in pounds also.; Sincerely, Joseph J. Levin, Jr., 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.