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: aiam2338OpenMr. K. Nakajima, Director/General Manager, Factory Representative Office, Toyota Motor Sales, U.S.A., Inc., 1099 Wall Street, West Lyndhurst, NJ 07071; Mr. K. Nakajima Director/General Manager Factory Representative Office Toyota Motor Sales U.S.A. Inc. 1099 Wall Street West Lyndhurst NJ 07071; Dear Mr. Nakajima: This is in response to your March 24, 1976, letter concerning the labe required by S 567.4(g) of 49 CFR Part 567, *Certification*.; The certification label is required by paragraph (g)(3) to includ ''GROSS VEHICLE WEIGHT RATING' or 'GVWR' followed by the appropriate value in pounds...' Paragraph (g)(4) specifies a similar requirement for Gross Axle Weight Ratings.; You have pointed out that the Canadian motor vehicle safety regulation require a similar certification label with these weight ratings expressed in kilograms. You have asked whether a single label that expresses the weight ratings in both pounds and kilograms would be permitted by 49 CFR Part 567. The answer is yes, provided that each kilogram rating, which is optional, appear after the corresponding pound rating, which is required.; Please note that these two ratings differ in legal status. The ratin that is expressed in pounds is the official rating for the purposes of the United States Federal motor vehicle safety standards and regulations. The accompanying equivalent kilogram rating, however, will be considered as optional, supplementary information provided for the guidance of the reader. This distinction is necessary, because the measurement values, including weights, that appear in our safety standards and regulations are specified in exact terms, without tolerances. While a measurement in English units can be 'equal' to one in metric units to any preselected number of significant figures, the two can never be exactly equal.; Yours truly, Frank Berndt, Acting Chief Counsel |
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ID: aiam5107OpenMr. Curtis J. Crist Product Development US Marine P.O. Box 9029 Everett, WA 98206; Mr. Curtis J. Crist Product Development US Marine P.O. Box 9029 Everett WA 98206; Dear Mr. Crist: This responds to your letter of December 10, 1992, i which you ask for confirmation that the provisions of paragraph S4.3.1.3 of Motor Vehicle Safety Standard No. 108 relating to front side marker lamps for boat trailers remain unchanged from interpretations provided by this Office in 1976 and 1977. I am pleased to confirm that these requirements remain the same. Paragraph S4.3.1.3, however, was renumbered S5.3.1.3 several years ago. You have also asked as to what action you must take for elimination of the requirement for rear identification lamps on boat trailers 80 or more inches in overall width. You may file a petition for rulemaking requesting this change. I enclose a copy of 49 CFR Part 552, the regulation governing these petitions, which will advise you as to these procedures. Section 552.4 sets forth the information that the petition should contain, and the address to which it must be sent. Sincerely, Paul Jackson Rice Chief Counsel Enclosure; |
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ID: aiam0755OpenMr. Herbert O. Staiger, Jr., Secretary-Treasurer, Airport Truck Center, Inc., 50 Murphy Road, Hartford, CT 06114; Mr. Herbert O. Staiger Jr. Secretary-Treasurer Airport Truck Center Inc. 50 Murphy Road Hartford CT 06114; Dear Mr. Staiger: This is in response to your letter of May 23 to Mr. Schneider regardin incomplete vehicle certification and your responsibility as a truck dealership.; The regulation to which you refer is 49 CFR Part 568, *Vehicle Manufactured in Two or More Stages*. It applies to incomplete vehicle manufacturers, intermediate manufacturers, and final-stage manufacturers of vehicles manufactured in two or more stages. Truck dealers who perform these manufacturing functions are required to meet these requirements, a copy of which is enclosed for your information. The regulations do not apply to a truck dealer who does not modify completed vehicles received from a manufacturer or distributor.; Other Federal motor vehicle safety regulations and standards ar codified in Chapter V of Title 49, Code of Federal Regulations.; Yours truly, Richard B. Dyson, Assistant Chief Counsel |
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ID: aiam2768OpenMr. Joe Devane, Dorsey Trailers, Inc., Hickman Avenue, Elba, Alabama 36323; Mr. Joe Devane Dorsey Trailers Inc. Hickman Avenue Elba Alabama 36323; Dear Mr. Devane: This responds to your telephone request of February 9, 1978, to Roge Tilton of my staff asking whether Standard No. 120, *Tire Selection and Rims for Motor Vehicles Other Than Passenger Cars*, requires that you mount on your vehicles only retreaded tires containing the DOT symbol.; The standard in paragraph S5.1.3 requires that after January 1, 1978 all used tires mounted on vehicles covered by the standard be manufactured in accordance with Standard No. 119 as evidenced by the symbol DOT on the sidewall. Therefore, you would not be permitted to mount used tires on your vehicles that do not contain the DOT symbol.; Retreaded tires are not used tires. Retreaded tires must comply wit all applicable Federal requirements pertaining to them. In the case of retreaded nonpassenger car tires, there are no applicable Federal standards. The DOT symbol is only marked on those tires to which a Federal standard applies. Therefore, retreaded nonpassenger car tires do not need to be marked with the DOT symbol and, in fact, should not be marked with that symbol. Retreaded nonpassenger car tires without DOT Symbols can be mounted on your vehicles in full compliance with Standard No. 120. If the tires in your possession have the DOT symbol on them, they can still be mounted on your vehicles. The tire retreader would be responsible for the misapplication of the DOT symbol to these tires.; Sincerely, Joseph J. Levin, Jr., Chief Counsel |
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ID: aiam1847OpenHonorable Stuart Symington, United States Senate, Washington, DC 20510; Honorable Stuart Symington United States Senate Washington DC 20510; Dear Senator Symington: This is in response to your letter of March 5, 1975, requesting ou comment on inquiries you have received concerning a proposed weakening of the 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 1979 model year. The impact requirements would then be increased to 4 mph for 1979 and later model year cars.; The proposal was based primarily on the results of two agency-sponsore 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 on March 12, 1975 (Docket No. 74-11, Notice 7, Docket No. 73-19, Notice 6).; Your interest in this matter is appreciated. Sincerely, Robert L. Carter, Associate Administrator, Motor Vehicl Programs; |
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ID: aiam5557OpenMr. Douglas Helbig Vice President Spencer Testing Services P.O. Box 429 Spencer, WV 25276; Mr. Douglas Helbig Vice President Spencer Testing Services P.O. Box 429 Spencer WV 25276; Dear Mr. Helbig: This responds to your letter asking me to confirm you belief that the National Highway Traffic Safety Administration (NHTSA) lacks the authority to require the periodic reinspection of Compressed Natural Gas (CNG) containers used as fuel tanks on alternative fuel motor vehicles. You are correct. NHTSA has no authority to require the reinspection of motor vehicles or items of motor vehicle equipment. Congress has authorized NHTSA to issue Federal motor vehicle safety standards (FMVSSs) for new motor vehicles and new items of motor vehicle equipment. The agency has used this authority to issue FMVSS No. 304, Compressed natural gas fuel container integrity, (49 CFR 571.304) which specifies requirements for the integrity of new CNG containers used to fuel motor vehicles. Each new CNG container manufactured on and after March 27, 1995 (the date the standard took effect) must comply with FMVSS No. 304 and be certified as complying with that standard when it is sold. However, after the first consumer purchase of a motor vehicle or an item of motor vehicle equipment, NHTSA's authority is much more limited and does not extend to the reinspection of motor vehicles or such equipment. I wish to note that another agency of the U.S. Department of Transportation, the Research and Special Programs Administration (RSPA), is authorized by Congress to issue standards for containers, including CNG containers, used to transport hazardous materials. RSPA, however, does not have the statutory authority to regulate CNG containers that are used to fuel a motor vehicle. In other words, there are no Federal requirements applicable to the reinspection of CNG containers designed to fuel a motor vehicle. I hope you find this information helpful. If you have any other questions, please contact Marvin Shaw at this address or by phone at (202) 366-2992. Sincerely, John Womack Acting Chief Counsel; |
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ID: aiam2292OpenMr. John Eckhold, Automotive Safety Director, Ford Motor Company, The American Road, Dearborn, MI 48121; Mr. John Eckhold Automotive Safety Director Ford Motor Company The American Road Dearborn MI 48121; Dear Mr. Eckhold: I am writing to inform you that the National Highway Traffic Safet Administration (NHTSA) will, for a limited time, refrain from enforcing one portion of 49 CFR Part 575, *Consumer Information Regulations*.; Subpart B of Part 575 specifies certain items of consumer informatio that apply to motor vehicles and their tires. Section 575.6 in Subpart A requires this information to be delivered to first purchasers (paragraphs (a) and (b)), made available to prospective purchasers (paragraph (c)) and submitted to the NHTSA (paragraph (d)). In particular, S 575.6(d) requires that:; >>>Each manufacturer of motor vehicles...shall submit to th Administrator 10 copies of the information specified in Part B of this part that is applicable to the vehicles or tires offered for sale, at least 30 days before that information is first provided for examination by prospective purchasers pursuant to paragraph (c) of this section.<<<; I understand that the strike by the United Rubber Workers has, b cutting off the supply of new tires, created an emergency situation within the motor vehicle industry, making it difficult for a manufacturer to know more than several days before it completes a vehicle which tires will be available for installation on the vehicle. I understand further that the provision of such information to the NHTSA 30 days before it is made available to prospective purchasers has become virtually impossible.; In view of the impracticability under the current circumstances of th 30-day-notice requirement, the NHTSA has concluded that enforcement of the requirement at this time is inappropriate. Accordingly, with respect to vehicles offered for sale during the strike and the 60-day period following its settlement, the NHTSA will refrain from enforcing the 30-day-notice requirement in S 575.6(d). Submittals of information to the agency must continue to be made, however, not later than the time the information is made available to prospective purchasers. With respect to vehicles that will be offered for sale at the expiration of the 60-day period, the NHTSA expects to begin receiving submittals after the thirtieth day following settlement of the strike.; Please note that the requirements of paragraphs (a), (b), and (c) of 575.6, as well as Federal Motor Vehicle Safety Standard No. 110, *Tire Selection and Rims--Passenger Cars*, are not affected by this letter.; Sincerely, James B. Gregory, Administrator |
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ID: aiam2787OpenMr. Donald L. Fowler, Ullman, Fowler & Jeffries, Inc., 2231 Devine Street, Columbia, SC 29205; Mr. Donald L. Fowler Ullman Fowler & Jeffries Inc. 2231 Devine Street Columbia SC 29205; Dear Mr. Fowler: This responds to your March 6, 1978, letter asking about the complianc responsibilities of a final-stage manufacturer who mounts a body on a motor vehicle chassis. In the situation you describe, the chassis would have been tested for compliance with the standards by the chassis manufacturer and the body would have been tested by the body manufacturer. You ask whether the final assembler would be required to crash test the vehicle as assembled.; The chassis manufacturer has responsibilities for compliance wit Federal safety standards that are outlined in Part 567, *Certification*, and Part 568, *Motor Vehicles Manufactured in Two or More Stages*, of our regulations. The chassis manufacturer must include with its chassis an incomplete vehicle document that describes how to complete the vehicle without impairing the compliance of the chassis with Federal safety standards. Although not required by our regulations, body manufacturers often provide documents addressing the compliance of their vehicle bodies with applicable safety standards. If a body that complies with Federal standards is mounted in accordance with the instructions of the incomplete vehicle document, the final-stage manufacturer can ordinarily assume that the completed vehicle complies with the safety standards. Based upon this assumption, it can certify that the vehicle complies with all applicable standards.; By following the instructions of the incomplete vehicle manufacture and relying upon the statements of the body manufacturer, the final-stage manufacturer would be considered to have exercised due care in ensuring that the vehicle complies. However, if the final-stage manufacturer does not follow the incomplete vehicle manufacturer's instructions or in some way makes a major modification that would affect the compliance of the vehicle, it might become necessary for it to undertake some further testing to ensure continued compliance. The amount of further testing, in these instances, would depend upon the extend of modification of the vehicle body or chassis.; For your information, our safety standards and regulations are locate in Volume 49 of the Code of Federal Regulations Parts 501 *et seq*. I am enclosing a sheet which details the applicability of Federal standards to various vehicles.; If after reading this letter, you still have questions that require meeting, contact Roger Tilton of my staff.; Sincerely, Joseph J. Levin, Jr., Chief Counsel |
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ID: aiam5042OpenMr. R.J. Misorski Director, Maintenance & Repair Maersk Inc. 231 Tyler Street Port Newark, NJ 07114; Mr. R.J. Misorski Director Maintenance & Repair Maersk Inc. 231 Tyler Street Port Newark NJ 07114; "Dear Mr. Misorski: This responds to your letter of August 6, 1992 asking for an interpretation of Federal Motor Vehicle Safety Standard No. 108. You write with reference to an amendment that became effective December 1, 1991, requiring a minimum of 12 square inches of lens area for rear stop or turn signals on vehicles over 80 inches wide, regardless of the separation between lamps. You request confirmation of your feeling that 'equipment manufactured prior to December 1, 1991 would be exempt from this ruling', and that 'it only applies to equipment that is manufactured after December 1, 1991.' You have asked for this interpretation to 'ensure compliance with our equipment fleet.' What the amendments require is that multipurpose passenger vehicles, buses, trucks, and trailers whose overall width is 80 inches or more, which are manufactured on and after December 1, 1991, be equipped with stop and turn signal lamps that meet the new requirements. Stop and turn signal lamps which were manufactured prior to that date that do not meet the new requirements are permissible to replace original equipment of the same type on vehicles manufactured before December 1, 1991, but they cannot be used as either original or replacement stop and turn signal lamps on vehicles manufactured on and after December 1, 1991. Furthermore, Standard No. 108 continues to allow manufacture and sale on and after December 1, 1991, of the old type of stop and turn signal lamps for replacement of original equipment on vehicles manufactured prior to December 1, 1991. I hope that this assists you with your compliance question. We shall be pleased to answer any further questions you may have. Sincerely, Paul Jackson Rice Chief Counsel"; |
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ID: aiam3895OpenMr. Giorgio Kirchner, Segreteria Generale, Federazione Italiana Fuoristrada, 20131 Milano, Via Capranica, 4, ITALY; Mr. Giorgio Kirchner Segreteria Generale Federazione Italiana Fuoristrada 20131 Milano Via Capranica 4 ITALY; Dear Mr. Kirchner: This responds to your letter asking for information about U.S. Federa laws covering tires. For your information, I have enclosed a copy of a letter I sent to a Brazilian tire manufacturer last year, explaining all of the requirements which must be satisfied by a foreign manufacturer selling tires in the United States and enclosing copies of the pertinent regulations.; You stated that you were particularly interested in knowing th meanings and the corresponding values of identification symbols required to appear on sidewalls of tires subject to Standard No. 119. You listed as examples of symbols you were interested in load range and 'P.R.'; The load range is a letter between 'A' and 'N', with an A being th lowest load range and N being the highest. Load ranges are assigned to tires for use on motor vehicles other than passenger cars because such tires may have identical physical dimensions and, therefore, identical size designations, but widely differing load-carrying capabilities. To ensure that these ties are used only in situations where their load-carrying capability is sufficient, section S6.5(j) of Standard No. 119 requires a letter designating the load range to appear on the sidewall of each tire for use on motor vehicles other than passenger cars. If you are interested in learning the load-carrying capability of the load ranges assigned to a particular tire size, you should contact one of the standardization organizations listed in section S5.1(b) of the enclosed copy of Standard No. 119.; I believe that the symbol 'P.R.' refers to the ply rating for a tire The ply rating is an older system which performed the same function now served by the load range. Under the ply rating system, tires were rated from 2 to 24 plies, with the lower numbers indicating a less load- carrying capability. Standard No. 119 does *not* require that a ply rating appear on the sidewall of tires. I have enclosed a copy of a page from the most recent yearbook published by the American standardization organization, the Tire & Rim Association, which shows how to convert a ply rating to the appropriate load range.; If you need further information or have any questions on the enclose materials, please feel free to contact me.; 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.