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: aiam3184OpenMr. Jeffrey Libman, President, Edison Rubber Company, P.O. Box 254, Edison, New Jersey 08817; Mr. Jeffrey Libman President Edison Rubber Company P.O. Box 254 Edison New Jersey 08817; Dear Mr. Libman: This responds to your letter of November 9, 19799, inquiring if it i permissible for you suppliers to cut off the DOT serial numbers on used tires before selling those tires to your company. You stated in your letter that your company buys used tires from several companies. These tires generally either have cuts in the tread or sidewalls or are out of round. Your company then resells the tires to another company, which resells the tires to the public.; The answer to your question is no. The presence of the DO identification number on tires is required by several of this agency's regulations. Our tire identification and record keeping regulation (49 CFR Part 574) requires that each manufacturer place the DOT number on at least one sidewall of each tire that it manufactures. The number serves several purposes. It is indispensable in aiding consumers to identify tires subject to a recall campaign for safety defects and noncompliances with the safety standards. It also aids this agency in enforcing its tire safety standards. Federal Motor Vehicle Safety Standards 109 (Passenger car tires, 49 CFR 571.109) and 119 (Tires for vehicles other than passenger cars, 49 CFR 571.119) require that each tire manufacturer certify that its tires conform to all applicable Federal Safety standards by branding or molding the DOT number on the tire.; Section 108(a) (2) (A) of National Traffic and Motor Vehicle SAfety Ac of 1966, as amended (15 U.S.C. 1397(a) (2) (A)), states 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...an item of motor vehicle equipment in compliance with an applicable Federal motor vehicle safety standard...' By removing the DOT identification number from a tire, the person would be knowingly rendering inoperative an element of design on the tire which is included on the tire for compliance with the requirements of a Federal motor vehicle safety standard. Section 109 of the Act (15 U.S.C. 1398) specifies a penalty of up to $1,000 for each violation of section 108.; Sincerely, Frank Berndt, Chief Counsel |
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ID: aiam2449OpenMr. Byron Crampton, Truck Body and Equipment Association, 5530 Wisconsin Ave., Suite 1220, Washington, DC 20015; Mr. Byron Crampton Truck Body and Equipment Association 5530 Wisconsin Ave. Suite 1220 Washington DC 20015; Dear Mr. Crampton: This responds to the Truck Body and Equipment Association's November 8 1976, question whether any provision of Standard No. 120, *Tire Selection and Rims for Motor Vehicles Other than Passenger Cars*, prohibits the certification of a vehicle following the addition of an axle system (typically known as a 'tag' or 'pusher' axle) that is not equipped with tires or rims at the time of sale and delivery to the first purchaser for purposes other than resale.; The answer to your question is no. The requirement of S5.1.1 that '. . each vehicle equipped with pneumatic tires for highway service shall be equipped with tires that meet specified requirements . . . ' prohibits the installation of tires that do not meet certain performance requirements, but it is not a requirement that tires be fitted to every axle of a vehicle prior to certification and sale.; I would like to point out that S 567.4(g)(4) of Part 567 *Certification*, requires that a gross axle weight rating be assigned to each axle system. Section S5.1.2 of Standard No. 120 specifies that the GAWR be not more than the sum of the maximum load ratings of the tires fitted to the axle in question. While the agency interprets Standard No. 120 to permit the assignment of a GAWR on the basis of tires listed on the certification plate for that GAWR, the assignment of an arbitrarily high (or low) GAWR for purposes such as avoiding a Federal motor vehicle safety standard (such as Standard No. 121, *Air Brake Systems*), would constitute a violation of S108(a)(1)(D) of the National Traffic and Motor Vehicle Safety Act:; >>>S108(a)(1) No person shall (A) . . . (c) (sic) Fail to issue a certificate required by section 114 of thi title, or issue a certificate to the effect that a motor vehicle or item of motor vehicle equipment conforms to all applicable Federal motor vehicle safety standards, if such person in the exercise of due care has reason to know that such certification is false or misleading in a material respect.<<<; Sincerely, Frank A. Berndt, Acting Chief Counsel |
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ID: aiam0233OpenMr. Donald B. Haaversen, 2833 Harriet Avenue, South, Minneapolis, Minnesota 55408; Mr. Donald B. Haaversen 2833 Harriet Avenue South Minneapolis Minnesota 55408; Dear Mr. Haaversen: Thank you for your letter of March 9, 1970, to the National Highwa Safety Bureau, concerning our Federal motor vehicle tire standards.; The only tire standard promulgated to date is Federal Motor Vehicl Safety Standard No. 109, 'New Pneumatic Tires-Passenger Cars' which was effective January 1, 1968. This standard specifies minimum performance for size, strength, endurance, high speed laboratory testing and labeling. For your information, I have enclosed a copy of Standard No. 109 and No. 110 with amendments.; The replies to your specific questions are as follows: >>>1. *Question:* New American made tires have DOT load ranges, loa capacity and inflation pressures molded into the sidewall. Is this required (that they be *permanently* marked), or is it sufficient to affix a temporary marking (such as a sticker) with this same information?; *Response:* Section S4.3 states that this information shall b permanently molded into or onto all new passenger car tires manufactured after August 1, 1968. If the tire was manufactured between January 1, 1968 and July 31, 1968 the labeling requirements may be met by use of a label or tag.; 2. *Question:* How is load capacity information arrived at? Is it b manufacturer certification, government conducted tests, or some other method?; *Response:* The load/inflation schedule is calculated by use o empirical formulas and coordinated through the various Tire and Rim Associations as well as the Society of Automotive Engineers.; 3. *Question:* Is it necessary that these tires be subject to safet tests? These particular tires are already imported by another organization and may already have passed the necessary tests, if any.; *Response:* The application of the 'DOT' recital to a tire, is the tir manufacturers self certification that his tire conforms to all the minimum performance standards of Federal Motor Vehicle Safety Standard No. 109.<<<; I have also enclosed for your review and information the followin data:; >>>1. U.S. Customs Regulations for Importation of Motor Vehicles an Items of Motor Vehicle Equipment.; 2. Automobiles Imported Into the United States.<<< Sincerely, Rodolfo A. Diaz, Acting Associate Director, Motor Vehicl Programs; |
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ID: aiam1849OpenMr. Robert Marx, State Representative, District No. 34, Polk-Benton, House of Representatives, Salem OR 97310; Mr. Robert Marx State Representative District No. 34 Polk-Benton House of Representatives Salem OR 97310; Dear Mr. Marx: This is in response to your letter of March 10, 1975, requestin information concerning correspondence from one of your constituents, Mr. Jim Lee Martin, commenting on a proposed amendment to the Federal Bumper Standard.; On January 2, 1975, the National Highway Traffic Safety Administratio (NHTSA) issued a Federal Register notice (copy enclosed) proposing to reduce the current 5 mph bumper impact requirements to 2.5 mph until the 1970 (sic) model year. The impact requirements would have been increased to 4 mph for 1979 and later model year cars.; The proposal was based primarily on the results of two ageny- sponsore (sic) studies which indicated that the cost and weight of many current production bumpers, in light of inflation and fuel shortages, made the bumpers no longer cost beneficial. Information presented at public hearings on the bumper notice and comments submitted to the docket in response to the proposal have brought to light additional data. The NHTSA has carefully examined all of this evidence and reviewed its studies in light of the new information. As a result, the agency has concluded that the 5 mph protection level should not be reduced. This decision is contained in a Federal Register notice that was published March 12, 1975, which is enclosed (Docket No. 74-11, Notice 7, Docket No. 73-19, Notice 6).; Mr. Martin has directed his comments to what he believes to be proposed requirement that vehicles manufactured in the future be equipped with plastic bumper systems. Such an understanding of the proposal is incorrect. The January 2, 1975 proposal was aimed at enabling a reduction in vehicle weight. In the preamble to that notice, the NHTSA cited soft face bumpers as one type of system that could produce a significant weight reduction. However, no proposal was made to require the use of soft face (plastic) systems. The March 12, 1975 notice reiterates the agency's position that bumpers which are lighter in weight than those currently in mass production could and probably would be developed. The requirements proposed in the March notice, however, ensure that a wide variety of materials could continue to be used in bumper systems.; Yours truly, Richard B. Dyson, Assistant Chief Counsel |
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ID: aiam5519OpenMr. Paul Pinoski Project Engineer SLP Engineering, Inc. 1501 Industrial Way North Toms River, NJ 08755; Mr. Paul Pinoski Project Engineer SLP Engineering Inc. 1501 Industrial Way North Toms River NJ 08755; "Dear Mr. Pinoski: This responds to your letter to me in which yo requested an interpretation of the term 'vehicle capacity weight,' as defined in Federal motor vehicle safety standard (FMVSS) No. 110, Tire selection and rims (49 CFR 571.110). I apologize for the delay in our response. FMVSS No. 110 applies to passenger cars. Section S4.3 of the standard requires a placard to be placed on the door of the glove compartment or other accessible place on which shall be displayed, among other things, the 'vehicle capacity weight.' This term is defined in S3 as meaning 'the rated cargo and luggage load plus 150 pounds times the vehicle's designated seating capacity.' You asked how to obtain the 'rated cargo and luggage load,' so that you can calculate vehicle capacity weight. The agency does not define the term 'rated cargo and luggage load' or otherwise regulate how that load is determined. The term simply refers to the vehicle manufacturer's determination of the cargo and luggage carrying capacity of the vehicle. The choice of methodology to be used in making that determination is left to the discretion of the vehicle manufacturer. From a safety standpoint, the important issue is the overall value specified by the vehicle manufacturer as the loaded weight of a vehicle. That value is also known as the gross vehicle weight rating (GVWR). The GVWR informs a vehicle owner how heavily he or she can load a vehicle. The only express regulatory limitation on the GVWR manufacturers may assign to their vehicles is set forth in 49 CFR 567.4(g)(3), which provides that the assigned GVWR 'shall not be less than the sum of the unloaded vehicle weight, rated cargo load, and 150 pounds times the vehicle's designated seating capacity.' (Emphasis added.) 'Rated cargo load' and 'rated cargo and luggage load' are interchangeable terms. I hope this information is helpful to you. Should you have further questions or need additional information, please feel free to contact Walter Myers of my staff at this address or at (202) 366-2992. Sincerely, Philip R. Recht Acting Chief Counsel Enclosure"; |
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ID: aiam1080OpenMr. T. Hiramine, Director, Takata Kojyo Co., Ltd., No. 10 Mori Building, 28 Sakuragawa-Cho, Nishikubo, Shiba, Minato-Ku, Tokyo, Japan; Mr. T. Hiramine Director Takata Kojyo Co. Ltd. No. 10 Mori Building 28 Sakuragawa-Cho Nishikubo Shiba Minato-Ku Tokyo Japan; Dear Mr. Hiramine: Thank you for your letter of February 24, 1973, to Mr. Franci Armstrong, requesting various interpretations of Standards No. 208 and No. 209, with respect to safety belt systems.; Your first question, referenced to Figure No. 1 of the enclosure wit your letter, relates to the required strength of the webbing in the case where two widths are connected together in an upper torso assembly. Under the webbing strength requirements of S4.2(b) of Standard No. 209, both pieces of webbing in the upper torso restraint must, individually, meet a 4,000 pound strength test. Under the assembly performance requirements of S5.3(b) of Standard NO. 209, a common pelvic and upper torso restraint must meet a 3,000 pound strength test. The latter would be true regardless of whether sewing or other means is used to make the belt assembly.; Your second question, referenced to Figure 2 of the enclosure, relate to the bolt strength required in the belt assembly anchorage. Under the provisions of S4.1(f), 'equivalent hardware' is permissible in lieu of the 7/16 inch bolts. In such a case, the tests required under S4.3(c), as prescribed under S5.2(c), would be performed on the entire equivalent hardware, rather than on the individual components (bolts).; With respect to your third question, concerning the acceptability o belts that do not conform to the elongation requirements of Standard No. 209, our reply is that under the present circumstances such webbing would not conform to either Standard No. 208 or Standard No. 209. As a result of the decision by the United States Court of Appeals for the Sixth Circuit in *Ford* v. *NHTSA*, belts installed under Standard No. 208's third option in 1973 (S4.1.2.3) will have to conform to Standard No. 209. Unless Standard No. 209 is amended with respect to its elongation requirements, therefore, energy absorbing webbing of the type you describe will not be permitted in 1974 cars,; Yours truly, Richard B. Dyson, Assistant Chief Counsel |
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ID: aiam2263OpenMr. G.E. Adams, Technical Manager, Dunlop Limited, Engineering Group, Holbrook Lane Coventry CV6 4AA, England; Mr. G.E. Adams Technical Manager Dunlop Limited Engineering Group Holbrook Lane Coventry CV6 4AA England; Dear Mr. Adams: This is in response to your letter of March 17, 1976, requestin information concerning steps which you, as a manufacturer of wheel equipment which will be offered for importation into the United States, must take in order to comply with all applicable National Highway Traffic Safety Administration regulations.; You should be aware of 49 CFR Part 566, *Manufacturer Identification* and 49 CFR Part 573, *Defect Reports*. In addition, Federal Motor Vehicle Safety Standard No. 119, *New Pneumatic Tires for Vehicles Other Than Passenger Cars*, may be of interest to you. Copies of these rules and an information sheet entitled 'Where to Obtain Federal Motor Vehicle Safety Standards and Regulations' are enclosed for your convenience.; Section 110(e) of the National Traffic and Motor Vehicle Safety Act (1 U.S.C. S1399(e)) requires every manufacturer who offers a motor vehicle or item of motor vehicle equipment for importation into the United States to designate a permanent resident of the United States as his agent, upon whom service of all processes, orders, notices, decisions, and requirements may be made.; The procedural regulations (49 CFR 551.45) for designation of agen pursuant to the Act requires that it include:; >>>(1) A certification by its maker that the designation is binding o Dunlop Limited under the laws, corporate bylaws, or other requirements governing the making of the designation at the time and place where it is made,; (2) The full legal name, principle place of business and mailin address of Dunlop Limited,; (3) Trade names or other designations of origin of the products o Dunlop Limited that do not bear its legal name,; (4) A provision that the designation of agent remain in effect unti with drawn or replaced by Dunlop Limited,; (5) A declaration of acceptance duly signed by the agent appointed which may be an individual, a firm, or a U.S. Corporation, and (6) The full legal name and address of the designated agent.<<<; A copy of the procedural regulation for designation of agent i enclosed for your convenience.; Sincerely, John Womack, Assistant Chief Counsel |
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ID: aiam0541OpenMr. Howard E. Ballard, Ballard Manufacturing Company, 1063 E. Third Street, Pomona, CA, 91766; Mr. Howard E. Ballard Ballard Manufacturing Company 1063 E. Third Street Pomona CA 91766; Dear Mr. Ballard: This is in reply to your letter of July 17, 1972, concerning th application of Motor Vehicle Safety Standard No. 302, 'Flammability of Interior Materials.' You raise several questions in your letter which are restated below.; >>>1. 'What is the 'grace' period after the law comes into effect. .?'; Standard No. 302 was issued on December 9, 1970, and became effectiv with respect to vehicles manufactured on or after September 1, 1972.; 2. 'Are we correct in assuming that slide-in campers and trave trailers are not affected by this law. . .?'; The Standard applies to passenger cars, multipurpose passenge vehicles, trucks, and buses. It does not apply to trailers (including 'fifth-wheel trailers') or slide-in (including 'cab over') campers.; 3. 'Does the foam in quilted plastic material need to b flame-retardant if the plastic itself (non-quilted) is already flame-proofed?'; 4. 'If the 1/4 inch foam used in quilted material is flame-proofed must a 5 inch core of foam used in a fabricated cushion be flame-proofed, also?'; The Standard provides a detailed description of the components require to meet its requirements, and of the depth of the materials in those components that are required to be tested. Generally, the answer to both of these questions is yes, material within 1/2 inch of the surface of an item is subject to the requirements.; 5. 'On recover jobs, must we replace customer's old foam wit flame-retardant foam?'; Standard No. 302 does not apply to replacement parts of aftermarke materials.; 6. 'Must the plywoods used for backs in dinettes be flame-proofed i the plastic or cloth used to upholster them is already flame-proofed?'; You should note that the Standard does not require 'flame-proofing, rather that the specimens must not burn at more than 4 inches per minute. The test specimens are determined by depth, as stated in our preceding answer, not by the nature of the material. The answer would therefore depend on whether the plywood is within 1/2 inch of the surface.<<<; Yours truly, Richard B. Dyson, Assistant Chief Counsel |
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ID: aiam1859OpenMr. Cleatis Mitchell, State Representative, District No. 52, House of Representatives, Salem, OR 97310; Mr. Cleatis Mitchell State Representative District No. 52 House of Representatives Salem OR 97310; Dear Mr. Mitchell: This is in response to your letter of March 3, 1975, requestin information concerning correspondence from Mr. Jim Lee Martin, commenting on a proposed amendment to the Federal Bumper Standard.; On January 2, 1975, the National Highway Traffic Safety Administratio (NHTSA) issued a Federal Register notice (copy enclosed) proposing to reduce the current 5 mph bumper impact requirements to 2.5 mph until the 1970 (sic) model year. The impact requirements would have been increased to 4 mph for 1979 and later model year cars.; The proposal was based primarily on the results of two ageny-sponsore (sic) studies which indicated that the cost and weight of many current production bumpers, in light of inflation and fuel shortages, made the bumpers no longer cost beneficial. Information presented at public hearings on the bumper notice and comments submitted to the docket in response to the proposal have brought to light additional data. The NHTSA has carefully examined all of this evidence and reviewed its studies in light of the new information. As a result, the agency has concluded that the 5 mph protection level should not be reduced. This decision is contained in a Federal Register notice that was published March 12, 1975, which is enclosed (Docket No. 74-11, Notice 7, Docket No. 73-19, Notice 6).; Mr. Martin has directed his comments to what he believes to be proposed requirement that vehicles manufactured in the future be equipped with plastic bumper systems. Such an understanding of the proposal is incorrect. The January 2, 1975 proposal was aimed at enabling a reduction in vehicle weight. In the preamble to that notice, the NHTSA cited soft face bumpers as one type of system that could produce a significant weight reduction. However, no proposal was made to require the use of soft face (plastic) systems. The March 12, 1975 notice reiterates the agency's position that bumpers which are lighter in weight than those currently in mass production could and probably would be developed. The requirements proposed in the March notice, however, ensure that a wide variety of materials could continue to be used in bumper systems.; Yours truly, Richard B. Dyson, Assistant Chief Counsel |
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ID: aiam3555OpenMr. Gary M. Ceazan, Vice President, Riken America, Inc., P.O. Box 3698 Terminal Annex, Los Angeles, Californian 90051; Mr. Gary M. Ceazan Vice President Riken America Inc. P.O. Box 3698 Terminal Annex Los Angeles Californian 90051; Dear Mr. Ceazan:This responds to your recent letter inquiring whethe it would be permissible for your company to label your tires in both the European metric size and the domestic P-metric size. Dual markings of sizes in the manner you have described are specifically prohibited by Federal Motor Vehicle Safety Standard No. 109 (49 CFR S 571.109).; Paragraph S4.3(a) of Standard No. 109 specifies that each tire shall b labeled with '*one* size designation, except that equivalent inch and metric size designations may be used.' A European metric size and its comparable domestic P-metric size are assigned different maximum load carrying capacities and different recommended maximum inflation pressures, because different formulae are used to calculate the load carrying capacities of the tires at the different inflation pressures. Because of the different load carrying capacities and recommended inflation pressures, substituting a European metric tire for a P-metric tire might cause the European metric tire to be unsafely overloaded. Dual markings could lead to such substitutions.; The dual-size markings you have requested were explicitly prohibite when this agency amended the labeling requirements of Standard No. 109 at 36 FR 1195, January 26, 1971. The prohibition has been expressly repeated in subsequent amendments addressing the question of tire labeling under the standard, *see* FR 10162, March 18, 1974, and 42 FR 12869, March 7, 1977. The agency s reasoning is that these dual size markings are a representation by the manufacturer that a particular tire meets all requirements of Standard No. 109 for both listed sizes, which is not true. In fact, dual-size markings represent a marketing effort by tire manufacturers to persuade consumers to change the size and/or type of tires mounted on their cars, i.e., by representing that the manufacturer's tire is an appropriate replacement for either European metric or P-metric tires. It is inappropriate to extend this marketing effort to the Federally required label on the tire. The only purpose of that label is to provide the consumer, in a straightforward manner, with technical information necessary for the safe operation of the consumer's automobile.; 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.