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: aiam3464OpenMs. Fran Anderson, Jellybean Express, 5131 Franklin Blvd., Sacramento, CA 95820; Ms. Fran Anderson Jellybean Express 5131 Franklin Blvd. Sacramento CA 95820; Dear Ms. Anderson: This responds to your letter of September 9, 1981, concerning th Federal flammability requirements applicable to seat covers for child restraints. As explained below, if the seat cover is sold as an item of original equipment on a child restraint system, it must meet the flammability requirements of Safety Standard No. 213, *Child Restraint Systems*. If the seat cover is sold as an item of aftermarket equipment, it is not covered by the standard. However, we would urge you to consider voluntarily complying with the standard.; Standard No. 213, *Child Restraint Systems* (49 CFR 571.213), set performance requirements for child restraints as pieces of motor vehicle equipment. Section 5.7 of the standard provides that, 'Each material used in a child restraint system shall conform to the requirements of S4 of Safety Standard No. 302 (S571.302.)' Standard No. 302, *Flammability of Interior Materials*, provides that when tested under specified conditions, material may not have a burn rate of more than 4 inches per minute (copy enclosed). Thus, if your seat cover is sold as a component on a new child restraint, that child restraint must comply with the requirements of S5.7 of Standard No. 213. Under the National Traffic and Motor Vehicle Safety Act (the Act, 15 U.S.C. 1392 *et seq*., copy enclosed), manufacturers have the responsibility of certifying that they comply with all applicable standards. The agency does not grant prior approval or conduct tests to support a manufacturer's certification. Therefore, I am returning the sample of your seat cover.; Although Standard No. 213 only covers the manufacture of items o original equipment in child restraints, sale of your seat cover as an item of aftermarket equipment is indirectly affected by Section 108(a)(2)(A) of the Act. That section provides:; >>>No manufacturer, distributor, dealer or motor vehicle repai business shall knowingly render inoperative, in whole or part, any device or element of design installed on or in a motor vehicle or item of motor vehicle equipment in compliance with an applicable Federal motor vehicle safety standard....<<<; Thus, none of the persons mentioned could not (sic) knowingly instal your seat cover on a used child restraint if it renders inoperative the restraint system's compliance with Standard No. 213. However, the prohibitions of the Act and the standard do not cover sale of your cover as an aftermarket device nor its installation solely by the vehicle or equipment owner.; Regardless of whether your seat cover must comply with Standard No 213, as a manufacturer of motor vehicle equipment you have defect responsibilities under sections 151 *et seq*. of the Act. Those sections provide that manufacturers of motor vehicles and motor vehicle equipment must notify owners of safety-related defects in their products and remedy those defects free of charge. If your covers are highly flammable, this could be regarded as a safety- related defect.; If you have any further questions, please let me know. Sincerely, Frank Berndt, Chief Counsel |
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ID: aiam3937OpenMr. Robert L. Hart, 19459 Manor, Detroit, MI 48221; Mr. Robert L. Hart 19459 Manor Detroit MI 48221; Dear Mr. Hart: This is in reply to your letter of February 11, 1985, to former Chie Counsel Frank Berndt asking for an interpretation that a combination stop lamp-rear view mirror you have invented would be permissible under paragraph S4.4.1 of Standard No. 108.; That paragraphs precludes combining a center high-mounted stop lam with any other lamp or reflective device. You have concluded that the prohibition applies only to passenger cars manufactured after September 1, 1985, 'and does not prohibit application of my device to vehicles manufactured prior to the effective date of the mandate.'; Actually, S4.4.1 does not apply to your device at all. The lam established by the standard is one that is mounted on the vertical centerline of the vehicle, at or near the rear window with no relationship to the forward left side of the vehicle where your combination lamp-mirror would be located. Standard No. 108 does contain in paragraph S4.1.3 a prohibition against additional lighting devices that impair the effectiveness of the lighting equipment required by the standard. But on the basis of the facts as you have presented them to us, we cannot say that impairment would exist. We therefore conclude that your device is not prohibited by Standard No. 108 as either original or replacement equipment on any motor vehicle.; However, Motor Vehicle Safety Standard No. 111, *Rearview Mirrors* does relate to your device. Passenger cars are required to be equipped with an outside rear view mirror on the driver's side, under paragraph S5.2.2 '...neither the mirror nor the mounting shall protrude farther than the widest part of the vehicle body except to the extent necessary to produce a field of view meeting or exceeding the requirements of S5.2.1.' Some of your designs show the lamp portion at the left end of the device's housing resulting in a wider unit than one incorporating a mirror alone. We recommend that you re-examine these designs with paragraph S5.2.2 in mind, relocating the lamp to the area either above or below that of the mirror surface if you conclude that the combination mounting would not comply with Standard No. 111.; There is no similar mounting requirement for driver's side mirrors o vehicles other than passenger cars, and your designs for mirrors on these vehicles would appear permissible under Standard No. 111.; Sincerely, Jeffrey R. Miller, Chief Counsel |
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ID: aiam2625OpenMr. Charles Owen Verrill, Jr., Patton, Boggs & Blow, 1200 Seventeenth Street, N.W., Washington, D.C. 20036; Mr. Charles Owen Verrill Jr. Patton Boggs & Blow 1200 Seventeenth Street N.W. Washington D.C. 20036; Dear Mr. Verrill: This responds to your April 20, 1977, petition to amend Standard No 120, *Tire Selection and Rims for Motor Vehicles Other Than Passenger Cars*. In your petition, you request that the National Highway traffic Safety Administration (NHTSA) permit the use of tires that have a maximum load rating of not less than 95% of the gross axle weight rating (GAWR) and not less than 95% of the gross vehicle weight rating (GVWR). Your petition is denied.; The problem addressed by your petition concerns a revision in the 197 Tire and Rim Manual that alters the load rating of tires. In effect, this revision will result in lower load ratings for certain tires. According to the facts you submit, the change in tire load rating will be implemented by tire manufacturers throughout the next few months which may not provide vehicle manufacturers sufficient time to correspondingly alter the GAWRs of their vehicles in accordance with the new tire load ratings. Therefore, for a short period of time, you allege that it will be impossible to obtain tires that correspond to the GAWR indicated on the vehicle.; To alleviate the above problem, you recommend rulemaking that woul permit vehicle manufacturers to install on their vehicles tires with load ratings slightly less than the GAWR of each axle. The NHTSA cannot permit the relief you request even for the limited time you propose. The intent of our tire standards is to provide minimum requirements for tires to ensure adequate safety. One of these minimum requirements mandates that the tire load rating be at least equal to the GAWR. Your request would have us reduce this minimum requirement. Since the matching of tires on a vehicle with the GAWR of each axle is such a basic principle of safety, the agency concludes that it would not be in the interest of safety to grant your request. Further, such an amendment might violate Section 202 of the National Traffic and Motor Vehicle Safety Act (15 U.S.C. S1381 *et seq*.), which requires that motor vehicles be equipped 'with tires which meet the maximum permissible load standards when such vehicle is fully loaded...'; As you may know, the label requirements of Standard No. 120 whic become effective in September permit you to list suitable tire and rim combinations on the vehicle. You need not equip a vehicle, however, with the tires indicated on the label. In this case, you may equip a trailer with any trailer tire that has a load rating equal to or greater than the GAWR of its associated axle. This may help resolve part of your problem with respect to a short term problem with matching tires on the vehicle with those indicated on the vehicle label.; Sincerely, Robert L. Carter, Associate Administrator, Motor Vehicl Programs; |
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ID: aiam0618OpenMr. Kent Chen, Import Manager, Mid-North American Import Export Company, Division of Charles, Incorporated, P. O. Box 529, Council Bluffs, IA 51501; Mr. Kent Chen Import Manager Mid-North American Import Export Company Division of Charles Incorporated P. O. Box 529 Council Bluffs IA 51501; Dear Mr. Chen: This is in reply to your letter of February 26, 1972, regardin importation of truck tires that were manufactured in Spain.; At the present time, the *proposed* Federal Motor Vehicle Safet Standard No. 119 that will apply to truck tires is in preparation. We expect that it will be issued in the very near future and that it will become effective on or about September 1, 1972.; Until then, truck tires are subject only to Regulation Part 574 - Tir Identification and Recordkeeping, which became effective May 22, 1971. Importation of truck tires for use on the public roads and highways requires compliance with Regulation Part 574. We are enclosing a copy of the regulation so that you may be informed of your obligations as an importer. You may use the listed tires or sell them to distributors and dealers if regulation requirements are satisfied.; We are also enclosing a pamphlet that contains additional guideline concerning importation of motor vehicles and equipment.; Apparently the tires described in your letter are manufactured in th Torrclavego, Santander, Spain plant of General Fabrica Espanola del Caucho, S.A. (General Tire International) and if manufactured since May 22, 1971, would be identified by the code marking *AB*.; Please let us know if we can be of further assistance in this matter. Sincerely, E. T. Driver, Director, Office of Operating Systems, Moto Vehicle Programs; |
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ID: aiam2275OpenHonorable Delbert L. Latta, House of Representatives, Washington, DC 20515; Honorable Delbert L. Latta House of Representatives Washington DC 20515; Dear Mr. Latta: Thank you for your March 23, 1976, request for consideration of th views of a constituent that provision of air cushion restraint systems in passenger cars would be too costly, and that motor vehicle regulation should concentrate on used vehicles because they are equipped with fewer safety and emission features.; As you are aware, the National Traffic and Motor Vehicle Safety Ac (the Act) (15 U.S.C. S 1391 *et seq*.) directs the Secretary of Transportation to issue motor vehicle standards that will reduce the number of accidents and deaths, and the severity of injuries, that occur on our nation's highways. The National Highway Traffic Safety Administration (NHTSA) of the Department of Transportation evaluates the available means to meet this goal. Restraining vehicle occupants to protect them against impact with the vehicle interior in a crash offers one of the greatest opportunities for improving motor vehicle safety. Reliance on existing seatbelt systems has prevented only a small portion of the death and injuries that occur from impact with the vehicle interior. For this reason, other means of providing restraint are under consideration. I can assure you that the issues of purchase cost, replacement cost, and the alternatives to air cushions are being included in this consideration.; The safe operation of motor vehicles has traditionally been regulate by the individual States and not the Federal Government. While the Act does not authorize the retrofit of safety devices to vehicles in use, the NHTSA has issued a highway safety program standard for State periodic motor vehicle inspection programs (23 CFR S 1204.4). Part 570, *Vehicle in Use Standards* (49 CFR Part 570), sets forth a procedure for inspection of older vehicles for use by the States in implementing the program standard. Also, the NHTSA has established demonstration diagnostic inspection projects that include emission as well as safety inspection of vehicles in use.; I have no basis for comment on the reported decision by Allstat Insurance Company not to consider the effects of bumper modification in establishing its premium structure.; I trust that this response will answer your constituent's questions. Sincerely, William T. Coleman, Jr. |
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ID: aiam0248OpenMr. P. F. Feran, Vice President, Bruce Duncan Company, Inc., 417 South Hill Street, Los Angeles, CA 90013; Mr. P. F. Feran Vice President Bruce Duncan Company Inc. 417 South Hill Street Los Angeles CA 90013; Dear Mr. Feran: This is in reply to your letter of July 20, 1970, in which you reques a ruling as to whether the Honda ATV is subject to the Federal Motor Vehicle Safety Standards and Regulations promulgated as a result of the National Traffic and Motor Vehicle Safety Act of 1966 (the Act).; The descriptive literature furnished with your letter states that, 'th machine looks to be street legal,' and shows that the vehicle has lighting equipment. Therefore, the Honda ATV, as described appears to be a 'motor vehicle' within the meaning of Section 102(3) of the Act, and specifically a 'motorcycle' as defined in 49 CFR 571.3(b). Motorcycle means a motor vehicle with motive power having a seat or saddle for the use of the rider and designed to travel on not more than three wheels in contact with the ground.; We trust this will clarify the situation for you. We will be pleased t answer any additional questions that you might have.; Sincerely, Francis Armstrong, Director, Office of Compliance, Moto Vehicle Programs; |
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ID: aiam3872OpenMr. William Shaw, Sales Manager, Shinn Fu Co., of America, Inc., 1004 Ancover Park, East Seattle, WA 98188; Mr. William Shaw Sales Manager Shinn Fu Co. of America Inc. 1004 Ancover Park East Seattle WA 98188; Dear Mr. Shaw: This is in reply to your letter of December 5, 1984, with respect t the permissibility under Federal regulations of a 'Supplemental Eye-Level Rear Stop Light' which provides functions additional to a stop signal.; Federal Motor Vehicle Safety Standard No. 108, *Lamps, Reflectiv Devices and Associated Equipment* specifies requirements only for center high-mounted stop lamps as original equipment on passenger cars, and for equipment that replaces original equipment center high mounted stop lamps.; If you offer this device to new car dealers for installation on ne cars before their sale, the dealer bears the responsibility for insuring that the car he sells complies with the center high mounted stop lamp requirements for new motor vehicles. On vehicles manufactured before September 1, 1986, equipped with the center lamp, that lamp may flash with the hazard warning lamp, but it cannot be combined with other lighting functions such as turn signal.; However, the device you wish to offer appears intended as a aftermarket device and not intended as original equipment for passenger cars. If this assumption is correct, there is no Federal standard that applies to it, and its legality must be determined according to the law of each State where it will be in use.; We hope that this information has been helpful. Sincerely, Frank Berndt, Chief Counsel |
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ID: aiam2760OpenMr. Edmund C. Burnett, Recreation Vehicle Industry Association, 5272 River Road, Suite 400, Washington, DC, 20016; Mr. Edmund C. Burnett Recreation Vehicle Industry Association 5272 River Road Suite 400 Washington DC 20016; Dear Mr. Burnett: This responds to your January 18, 1978, letter asking several question about the applicability of Standard No. 302, *Flammability of Interior Materials*, to several vehicle components that you submitted.; First you ask whether padded material used for the top portion of dashboard would be considered to fall within the ambit of the standard. As you stated in your letter, the National Highway Traffic Safety Administration has determined that a dashboard is considered a front panel and is included within the components subject to the standard. Therefore, since the padding you propose to use on the top of the dashboard constitutes part of the dashboard it is required to comply with all of the requirements of the standard.; In your second question you ask whether the same material mentioned i question 1 would be required to comply with the standard when used as a seat cushion. Paragraph S4.1, which lists the components covered by the standard, specifically includes seat cushions. Therefore, any material used for this purpose is required to comply with the standard.; In regard to both of the above questions, you ask whether a dashboar or seat cushion consisting of vinyl stitched at varying intervals to padding would be subject to two tests - one for the vinyl and one for the padding. Paragraph S4.2.1 states that: 'any material that does not adhere to other material(s) at every point of contact shall meet the requirements of S5.3 when tested separately.' When the vinyl is stitched to the padding in the manner outlined in your letter, the vinyl does not adhere to the material at every point of contact. Accordingly, the materials must be tested separately.; Your questions 3 and 4 require no response since the materials to whic you refer must be tested separately, not as composite materials.; In your question 5, you correctly state that the two top material would be required to be tested separately. If as installed in the vehicle the third layer of material would fall within 1/2 inch of the occupant compartment, then it too would be tested in accordance with the requirements. It does not matter that this material would not be within 1/2 inch of the surface when the stitching is removed for testing of each component separately. In a related question you ask whether the stitching itself would be tested. Since the stitching is part of the seat cushion, it is subject to the requirements and since it does not adhere at every point of contact, it should be tested separately. From the standpoint of practicality, however, the stitching cannot be tested separately in the prescribed manner, and is usually simply tested as part of the material itself.; Finally you submitted a section of headlining material and questio whether it would be required to comply with the requirements. This material falls within the list of components covered by the standard and, therefore, must comply with all of the requirements. The material that you submitted is composed of two layers joined at every point of contact and would be tested as a composite material.; Sincerely, Joseph J. Levin, Jr., Chief Counsel |
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ID: aiam2330OpenMr. Daryl Nims, Nims Sportsman, 225 Main Street, Ames, IA, 50010; Mr. Daryl Nims Nims Sportsman 225 Main Street Ames IA 50010; Dear Mr. Nims: This will confirm your telephone conversation of June 23, 1976, wit Mr. Vinson of this office concerning the preemptive effect of the Federal motor vehicle safety standards with respect to moped turn signals.; The Federal standards are issued pursuant to Title 15, United State Code, Section 1392(a). Judging that a multiplicity of State and Federal vehicle safety standards would constitute a burden on interstate commerce, Congress also enacted Section 1392(d), which prohibits a State from establishing or continuing in effect a vehicle safety standard that differs from a Federal safety standard covering the same aspect of vehicle performance. For example, Federal Motor Vehicle Safety Standard No. 108 contains requirements for motorcycle headlamp performance. Therefore, if a State has a standard on motorcycle headlamp performance it must be identical to the Federal one, and may not impose either greater or lesser requirements. On the other hand, there is no Federal standard for fog lamps, and a State may set whatever requirements it deems appropriate for fog lamps.; How does preemption apply to moped turn signals? Under the Federa standards, a moped is categorized as a 'motorcycle' since it is 'a motor vehicle. . .having a seat or saddle for the use of the rider and designed to travel on not more than three wheels in contact with the ground.' (Title 49, Code of Federal Regulations, Section 571.3(b)). For some purposes a moped is considered a 'motor-driven cycle' which is 'a motorcycle with a motor that produces 5-brake horsepower or less.' Standard No. 108 requires motorcycles manufactured on or after January 1, 1973, to be equipped with turn signal lamps. However, in recognition of the limited ability of low-powered motorcycles, Standard No. 108 was amended effective October 14, 1974, to add paragraph S4.1.1.26 which states that 'A motor- driven cycle whose speed attainable in 1 mile is 30 mph or less need not be equipped with turn signal lamps.' Pursuant to Section 1392(d) this means that a State can validly require a moped to be equipped with turn signal lamps in only two instances: If the moped were manufactured between January 1, 1973 and October 14, 1974, or if it were manufactured on or after October 14, 1974, and has a top speed exceeding 30 mph.; I hope this clarifies the matter for you. Sincerely, Frank A. Berndt, Acting Chief Counsel |
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ID: aiam3171OpenMr. R. M. Premo, Director, Vehicle Safety Activities, Sheller-Globe Corporation, 3555 St. Johns Road, Lima, OH 45804; Mr. R. M. Premo Director Vehicle Safety Activities Sheller-Globe Corporation 3555 St. Johns Road Lima OH 45804; Dear Mr. Premo: This responds to your November 12, 1979, letter asking whether severa joints in your school bus must comply with Standard No. 221, *School Bus Body Joint Strength*. All of the joints concern what you have called maintenance access panels.; As you are aware, the agency has discovered through its complianc testing that most school bus manufacturers have taken advantage of the maintenance access panel exemption from the standard. The result is that many joints in school buses are not as secure as they should be and, during an accident, might result in injury to children being transported in those buses. The agency is very concerned about this practice and is considering methods of limiting the maintenance access panel exemption.; Your letter asks the agency to consider the fact that the panels whos joints you are questioning are plastic and not metal. Therefore, you conclude that the edges are not sharp, and even if the panels come unfastened in an accident, their edges will not be likely to injure the occupants of your buses.; The standard establishes joint strength tests that apply uniformly t all joints regardless of the material used in the panel. While it may be true that plastic panels are less likely to injure occupants of buses when a panel becomes disconnected during an accident, Standard No. 221 addresses other safety areas beyond preventing the sharp edges of panels from cutting occupants. Joint strength is necessary for the vehicle integrity during accidents. This is as important as preventing cutting edges from panels. Accordingly, the agency will continue to subject all joints falling within the parameters of the standard to the requirements of the standard without regard to the material used in a panel.; With respect to the questions posed in your letter, you first as whether the right and left hand windshield pillar covers must comply with the standard. You indicate that a hose runs behind one pillar cover and a cable control runs behind the other. The agency has indicated that the installation of a wire, hose or cable behind a wall does not make that wall a maintenance access panel. Accordingly, the agency concludes that the joints connecting the pillar cover panel are subject to the standard.; Your questions 2, 4, and 5 refer to panels that cover motors which yo indicate must be serviced. The motors include the windshield wiper and heater motors. The agency is unable to determine from your pictures and sketches whether all of the joints surrounding these motors are subject to the standard. The joints connecting panels that *must* be removed for *routine* servicing of a vehicle's motors would not be considered as joints subject to the standard. However, these joints must be the minimum necessary for routine servicing of the motors. In compliance testing your vehicles, the agency will only exempt those joints that are necessary for routine servicing. We will not exempt adjacent panel joints simply because wires run beneath them.; In your third question you describe a dash trim panel that covers wiring harness, some chassis cowl mounting bolts, and an entrance door cable. The agency needs more information to make a formal determination with respect to this panel and its joints. Our inclination based upon the information that you have presented is that these would be joints subject to the standard, because the removal of this panel is not required for routine maintenance.; Your final question asks whether the entrance door control cover mus comply with the standard. You state only that it must be removed to remove the dash trim panel. As we stated in the last paragraph, we believe that the dash trim panel joints may be required to comply with the standard. If this is the case, it may also be necessary for the door control cover joints to comply with the standard. The key factor in determining whether this panel's joints must comply with the requirement is whether the panel must be removed for routine maintenance. You have not proven such a need in your letter, and therefore, the agency cannot give you a determination concerning the need for these joints to comply with the standard.; Sincerely, Frank Berndt, Chief Counsel |
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Request an Interpretation
You may email your request to Interpretations.NHTSA@dot.gov or send your request in hard copy to:
The Chief Counsel
National Highway Traffic Safety Administration, W41-326
U.S. Department of Transportation
1200 New Jersey Avenue SE
Washington, DC 20590
If you want to talk to someone at NHTSA about what a request for interpretation should include, call the Office of the Chief Counsel at 202-366-2992.
Please note that NHTSA’s response will be made available in this online database, and that the incoming interpretation request may also be made publicly available.