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: aiam0942OpenMr. R. L. Coleman, Assistant Manager, Crawford and Company Insurance Adjusters, 4915 Augusta Avenue, Post Office Box 6473, Richmond, VA 23230; Mr. R. L. Coleman Assistant Manager Crawford and Company Insurance Adjusters 4915 Augusta Avenue Post Office Box 6473 Richmond VA 23230; Dear Mr. Coleman: This is in reply to your letter of September 19, 1972, concerning a accident involving a 1972 International tractor which you maintain was not certified by its manufacturer as complying with applicable Federal standards. You state that the accident may have been due to 'insufficient gross vehicle weight'.; The Certifications regulations (49 CFR Parts 567,568) do requir final-stage manufacturers to certify the conformity of vehicles they complete, by affixing to them a label containing information specified in the regulations. In the case of vehicles manufactured on or after january 1, 1972, the regulations require that such information include a gross vehicle weight rating, and a gross axle weight rating for each axle. These ratings are set by the manufacturer based on definitional criteria found in the regulations (S 568.3, 49 CFR S 571.3). Your definition of a 'final-stage' manufacturer, 'anyone who installs a component that is not readily attachable', is correct only if the component installation is to an incomplete vehicle.; Your letter has been forwarded to our Office of Standards Enforcement who will conduct whatever investigation is appropriate to determine whether violations of NHTSA regulations have occurred. Such an investigation does not include ascertaining the cause of any accident, or whether a particular vehicle may have been overloaded. It concerns only whether the respective manufacturers have complied with NHTSA regulations applicable to them. If you wish to know the results of this investigation when it is completed, you may write our Office of Standards Enforcement, NHTSA, or call Mr. George Shifflett of that office at (202) 426-1693.; Yours truly, Richard B. Dyson, Assistant Chief Counsel |
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ID: aiam2713OpenMr. A. J. Burgess, Vice President, Lucas Industries, 5500 New King Street, Troy, MI 48098; Mr. A. J. Burgess Vice President Lucas Industries 5500 New King Street Troy MI 48098; Dear Mr. Burgess: This responds to Lucas Industries' November 1, 1977, request that th upcoming passive restraint requirements of Standard No. 208, *Occupant Crash Protection*, be amended to provide alternative compliance by means of installation of active lap and shoulder belts equipped with an ignition interlock system.; Section 125 of the National Traffic and Motor Vehicle Safety Act (th Act) provides in relevant part that 'No Federal motor vehicle safety standard may . . . provide that a manufacturer is permitted to comply with such standard by means of . . . any safety belt interlock system.' (15 U.S.C. 1410b(b)(1)). It is the agency's opinion that this provision operates as a strict prohibition on amendments of Standard No. 208 that would have the effect of permitting compliance by provision of an ignition interlock system. This opinion is confirmed by Conference Report language on S 125 which states:; >>>No matter what procedure is followed, the conference substitut prohibits the re-establishment of the safety belt interlock system or continuous buzzer as a mandatory or optional motor vehicle safety standard. H.R. Rep. 93-1452, 93rd Cong. 2d Sess at 45 (1974).<<<; In view of this statutory prohibition, Lucas Industries' request fo amendment of the upcoming requirements of Standard No. 208 cannot be considered by the agency.; Sincerely, Joseph J. Levin, Jr., Chief Counsel |
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ID: aiam4482OpenMr. Brian Hall President, VS Technology 3046 E. Dover St. Mesa, AZ 85213; Mr. Brian Hall President VS Technology 3046 E. Dover St. Mesa AZ 85213; "Dear Mr. Hall: This is in reply to your recent undated letter to Mr Vinson of this Office. You have described a safety apparatus and have requested 'approval' from the Department. The apparatus is a red light that is worn on the back of a rider on small open vehicles such as motorcycles. The light connects to the stop lamp system on the vehicle and is activated at the same time as the vehicle's stop lamp. The Department has no authority to 'approve' or 'disapprove' specific concepts or equipment. However, it can advise whether such is permissible or impermissible under Federal statutes or Departmental regulations. Yours is a unique device, and there are no Federal motor vehicle safety standards that apply to it. Our primary concern is whether its operation would in any way interfere with the effectiveness of the vehicle's stop lamp, such as a power drain that would make that light less bright. Because the apparatus is 'apparel not a system part...which is intended for use exclusively to safeguard motor vehicles, drivers, passengers...from risk of accident, injury, or death', it meets the statutory definition of 'motor vehicle equipment.' This means that the apparatus is subject to Federal notification and remedy provisions in the event a determination is made that it incorporates a defect that relates to motor vehicle safety. Because the Department has no authority to regulate how a vehicle is used on the public roads, you may wish to investigate whether the apparatus is acceptable under the laws of the individual States. The American Association of Motor Vehicle Administrators may be able to provide you with an answer. Its address is 4600 Wilson Boulevard, Arlington, Va. 22203. We appreciate your interest in improving safety. Sincerely, Erika Z. Jones 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: aiam5385Open"M. Guy Dorleans Valeo Vision 34, rue St-Andr 93012 Bobigny Cedex France"; "M. Guy Dorleans Valeo Vision 34 rue St-Andr 93012 Bobigny Cedex France"; Dear M. Dorleans: This responds to your FAX of April 20, 1994, to Mik Perel of this agency, asking for an interpretation of Standard No. 108. The drawing in your letter depicts a four-lamp headlamp arrangement in which the outermost lamps (lower beam) incorporate HB4 light sources, and the innermost lamps (upper beam), HB3 light sources. In operation, the outermost lamps alone provide the lower beam. However, when the upper beam switch is thrown, all lamps are energized. You ask for confirmation of your interpretation that 'outer unit must fulfill table 15a for Low Beam, an (sic) also that inner must fulfill with HB3 alone table 15a High Beam.' Paragraph S7.5 of Standard No. 108 specifies requirements for four-lamp replaceable bulb headlamp systems such as the one you describe. The photometrics that apply to such systems are set forth in paragraph S7.5(b): 'The photometrics as specified in subparagraphs (c) through (e) of this paragraph (depicted in Figure 26) . . . .' Because subparagraph (d) applies to a headlamp equipped with dual filament replaceable light sources and Types HB3 and HB4 are single filament sources, the applicable subparagraph is (e), and, more specifically, the four-headlamp specifications of (e)(3). This will confirm your understanding. Under S7.5(e)(3), the lower beam is to be produced by the outermost lamps and designed to conform to the lower beam requirements of Figure 15, the upper beam by the innermost lamps and designed to conform to the upper beam requirements of Figure 15. This is confirmed in Figure 26. However, the photometrics of Figure 15A will apply on and after September 1, 1994, (Paragraph S7.1). Simultaneous activation of both upper and lower beams is permitted by S5.5.8 of Standard No. 108 for headlighting systems designed to conform to Figure 15. Later this year, we will amend Standard No. 108 to substitute Figure 15A for Figure 15, effective September 1, 1994. Sincerely, John Womack Acting Chief Counsel; |
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ID: aiam2326OpenMr. Leroy E. Mueller, President, Wisconsin Trailer Company, Inc., Manufacturers Machinery Hauling Trailers, Richfield, WI 53076; Mr. Leroy E. Mueller President Wisconsin Trailer Company Inc. Manufacturers Machinery Hauling Trailers Richfield WI 53076; Dear Mr. Mueller: This responds to your June 2, 1976, request for written notificatio that the 'heavy hauler trailer' exclusion of Standard No. 121, *Air Brake Systems*, has been extended to September 1, 1977. You also request confirmation that manufacturers may assign multiple gross vehicle weight ratings (GVWR) and gross axle weight ratings (GAWR) in fulfilling their responsibilities under Part 567, *Certification* (49 CFR Part 567) of our regulations, but that only ratings unqualified by speed restrictions will be permitted after September or October 1976.; I have enclosed a copy of the amendment that extends the 'heavy hauler exclusion of Standard No. 121 from September 1, 1976, to September 1, 1977. The date change in that amendment has been circled.; The NHTSA requires that the GVWR and GAWR placed on the certificatio plate in accordance with Part 567 be unqualified by speed restriction and be based on the 60- mph capabilities assigned to the tire and rims by the United States Tire and Rim Association. Other GVWR and GAWR values may be assigned by the manufacturer, but they must be listed after the information required on the Part 567 certification plate, and they do not form the basis of a vehicle's compliance with safety standards such as Standard No. 121.; In our November 20, 1975, letter to you on the same subject, we note that we were considering a revision of the definition of GVWR and GAWR to conform to this interpretation. That proposal has been issued and a copy is enclosed for your information.; The proposal has not been made final as of the date of this letter Please note that multiple ratings would continue to be permitted under the proposal, so long as the restricted rating appears first on the certification plate.; Yours truly, Stephen P. Wood, Assistant Chief Counsel |
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ID: aiam2654OpenHonorable Lamar Gudger, House of Representatives, Washington, DC 20515; Honorable Lamar Gudger House of Representatives Washington DC 20515; Dear Mr. Gudger: Please excuse the delay in my response to your letter of June 15, 1977 addressed to Mr. Norman Sultan, with a copy to the National Highway Traffic Safety Administration (NHTSA) regarding the Federal requirement for registration of tires.; Mr. Sultan has reported a tire registration of 10 percent in his are of operation which is considerably less than the national figures of 30 percent for retreads and 70 percent for new tire replacements developed in our studies. Mr. Sultan is urging a change in the law to permit voluntary registration of all tires.; Mr. John Snow, my predecessor, reported to the Honorable Warren G Magnuson, Chairman of the Committee on Commerce, U.S. Senate, that consideration would be given to changing Regulation Part 574 allowing voluntary registration of retreaded tires in lieu of mandatory registration. Since taking office, I have devoted considerable attention to reviewing and analyzing the pertinent factors related to tire registration. I am convinced of the safety benefits of registering new tires and I consider the mandatory recordkeeping provision essential to the purpose of the Vehicle Safety Act. However, because retreaded tires are individually manufactured and therefore could not be recalled as are mass produced items, I am considering proposing revocation of the mandatory recordkeeping requirement for retreaded tires.; For your information I am enclosing a copy of my recent letter t Senator Magnuson in response to his questions on this subject.; You may be interested to know that a recent meeting wit representatives of the National Tire Dealers and Retreaders Association (NTDRA) provided an opportunity to discuss basic clerical problems associated with registration. As a result, an interpretation of the regulation was reached which would permit the tire purchaser personally to complete the registration form. Although dealer responsibility remains, the interpretation is considered by NTDRA to provide considerable relief to dealers in time and cost. Hopefully this action will offset much of the objections to the current tire registration process.; Sincerely, Joan Claybrook |
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ID: aiam2653OpenHonorable Lamar Gudger, House of Representatives, Washington, D.C. 20515; Honorable Lamar Gudger House of Representatives Washington D.C. 20515; Dear Mr. Gudger: Please excuse the delay in my response to your letter of June 15, 1977 addressed to Mr. Norman Sultan, with a copy to the National Highway Traffic Safety Administration (NHTSA) regarding the Federal requirement for registration of tires.; Mr. Sultan has reported a tire registration of 10 percent in his are of operation which is considerable less than the national figures of 30 percent for retreads and 70 percent for new tire replacements developed in our studies. Mr. Sultan is urging a change in the law to permit voluntary registration of all tires.; Mr. John Snow, my predecessor, reported to the Honorable Warren G Magnuson, Chairman of the Committee on Commerce, U.S. Senate, that consideration would be given to changing Regulation Part 574 allowing voluntary registration of retreaded tires in lieu of mandatory registration. Since taking office, I have devoted considerable attention to reviewing and analyzing the pertinent factors related to tire registration. I am convinced of the safety benefits of registering new tires and I consider the mandatory recordkeeping provision essential to the purpose of the Vehicle Safety Act. However, because retreaded tires are individually manufactured and therefore could not be recalled as are mass produced items, I am considering proposing revocation of the mandatory recordkeeping requirements for retreaded tires.; For your information I am enclosing a copy of my recent letter t Senator Magnuson in response to his questions on this subject.; You may be interested to know that a recent meeting wit representatives of the National Tire Dealers and Retreaders Association (NTDRA) provided an opportunity to discuss basic clerical problems associated with registration. As a result, an interpretation of the regulation was reached which would permit the tire purchaser personally to complete the registration form. Although dealer responsibility remains, the interpretation is considered by NTDRA to provide considerable relief to dealers in time and cost. Hopefully this action will offset much of the objections to the current tire registration process.; Sincerely, Joan Claybrook |
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ID: aiam2881OpenMr. Joe Henry, Office of the Attorney General, State Capitol, Charleston, WV 25305; Mr. Joe Henry Office of the Attorney General State Capitol Charleston WV 25305; Dear Mr. Henry: This is in response to your telephone conversation with Kathy DeMete of my staff on October 11, 1978, concerning the Federal odometer law. You requested an interpretation of the first sentence in 49 CFR S580.7, which reads as follows:; >>>Each dealer or distributor of a motor vehicle who is required b this Part to execute an odometer disclosure statement shall retain for four years each odometer mileage statement which he receives.<<<; Specifically, you asked whether dealers and distributors are require to retain only those disclosure statements which they actually receive or whether they are under an affirmative duty to obtain a disclosure statement if none is offered by the transferor.; In the opinion of the National Highway Traffic Safety Administration section 408 of the Motor Vehicle Information and Cost Savings Act (15 U.S.C. 1988) creates an affirmative duty on the part of dealers and distributors to obtain disclosure statements. Section 408 states that:; >>>No transferee who, for purposes of resale, acquires ownership of motor vehicle shall accept any written disclosure required by any rule prescribed under this section if such disclosure is incomplete.<<<; Part 580 of 49 CFR requires such written disclosure. If a disclosur statement, as required by Part 580, is provided to the transferee but is not filled out in its entirety, then the disclosure of the mileage the vehicle has been driven is not complete. Likewise, if no information at all is provided as to the mileage, then the disclosure is also incomplete. Therefore, in order for a dealer or distributor to be in compliance with section 408 of the Act, he must take steps to ensure that he receives a written disclosure and that it is complete in all respects prior to executing the transfer of ownership documents.; Part 580.7 of 49 CFR merely requires that those statements which th dealer or distributor is required to obtain are retained.; Sincerely, John Womack, Assistant Chief Counsel |
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ID: aiam0177OpenHonorable William Proxmire, United States Senate, Washington, DC 20510; Honorable William Proxmire United States Senate Washington DC 20510; Dear Senator Proxmire: Thank you for your letter of August 27, 1969, to the Director Legislative Liaison, Department of Transportation, concerning Mr. Eugene J. Shermeister's comments on headlamps for motor vehicles.; Enclosed for Mr. Shermeister's information is a copy of Federal Moto Vehicle Safety Standard No. 108 on lighting requirements for the vehicles specified in the standard. Standard No. 108 is applicable to new vehicles manufactured on or after the effective date of January 1, 1969. In accordance with the National Traffic and Motor Vehicle Safety Act of 1966, the initial safety standards were based on existing standards. Headlighting requirements, as specified in Standard No. 108, were therefore based on existing Bureau of Motor Carrier Safety Regulations, certain State regulations and the Society of Automotive Engineers (SAE) Standards. On this basis, Standard No. 108 specifies that headlamps for all vehicles except motorcycles conform to SAE Standards J579a and J580a, entitled, respectively, 'Sealed Beam Headlamp Units for Motor Vehicles' and 'Sealed Beam Headlamp.' To provide protection from blinding effects to oncoming drivers, SAE Standard J579a specifies a maximum lamp output of 37,500 candlepower. This candlepower value is considerably less than the candlepower output of quartz iodine type headlamps.; As indicated in paragraph S2 of Standard No. 108, the standard i applicable to lighting on new vehicles and not to replacement lighting equipment. Except for vehicles subject to the Bureau of Motor Carrier Safety Regulations, the requirements for replacement lighting equipment, as well as lighting requirements for vehicles in use, are those requirements as set by the regulatory agencies of the individual states.; The National Highway Safety Bureau is sponsoring a research contract o improved forward lighting for motor vehicles. Results of this contract will not only provide us with well-founded data for use in amending the standard, but will also assist us in evaluating the relative merits of sealed beam, quartz iodine and other types of headlamps.; Sincerely, W. M. Jacklin, Jr., Acting Director, Motor Vehicle Safet Performance Service; |
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.