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: aiam4742OpenJoseph R. Wheeler, Esq. P.O. Box 2808 424 Church St., Suite 2900 Third National Financial Center Nashville, TN 37219; Joseph R. Wheeler Esq. P.O. Box 2808 424 Church St. Suite 2900 Third National Financial Center Nashville TN 37219; "Dear Mr. Wheeler: This is in response to your letter to Kennet Weinstein of my staff requesting information about actions by the Secretary of Transportation pursuant to Federal Motor Vehicle Safety Standard No. 208, Occupant Crash Protection (49 CFR 571.208). More specifically, you noted that S4.1.4.1 of Standard No. 208 states that, 'Except as provided in S4.1.5 and another section not relevant to your inquiry , each passenger car manufactured on or after September 1, 1989 shall comply with the automatic restraint requirements .' S4.1.5 of Standard No. 208 provides that: 'If the Secretary of Transportation determines, by not later than April 1, 1989, that state mandatory safety belt usage laws have been enacted that meet the criteria specified in S4.1.5.2 and that are applicable to not less than two-thirds of the total population . . ., the automatic restraint requirements will not go into effect .' You asked whether the Secretary ever made a determination under S4.1.5 regarding State safety belt use laws. The answer is no. Under S4.1.5, the Secretary was not required to make any determination about any State safety belt laws. In fact, the Secretary never did so. Because no determination was made under S4.1.5, the automatic restraint requirements are now in effect for all passenger cars. This letter expresses no opinion about the implications under Tennessee law of the absence of a determination by the Secretary of Transportation regarding any State's safety belt law. Sincerely, Paul Jackson Rice Chief Counsel"; |
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ID: aiam3290OpenMr. Donald E. Boyd, Donald Boyd & Associates, Inc., 5617 W. 6th Street, Stillwater, OK 74074; Mr. Donald E. Boyd Donald Boyd & Associates Inc. 5617 W. 6th Street Stillwater OK 74074; Dear Mr. Boyd: This responds to your recent letter requesting confirmation that larg commercial truck tractors do not have to comply with Federal Motor Vehicle Safety Standard No. 216, *Roof Crush Resistance*. You also asked whether large trucks should be designed to comply with the 'belt system' option under Safety Standard No. 208, *Occupant Crash Protection*.; You are correct in your assumption that large commercial trucks woul not have to comply with Safety Standard No. 216 since that standard only applies to passenger cars. You are also correct in stating that trucks with a GVWR greater than 10,000 pounds may meet the seat belt option of Safety Standard No. 208 found in paragraph S4.3.2 Under S4.3.1, manufacturers do have the option of meeting the crash protection requirements of S5 by means that require no action by vehicle occupants (with current technology this means air cushion restraints or automatic seat belts). Further, vehicles manufactured prior to August 15, 1977, were permitted to comply with Safety Standard No. 216 in lieu of the 'rollover' requirements of Standard No. 208, and for large trucks this would have been a simple test to meet. However, since the vehicle would also have been required to meet the 'frontal' and 'lateral' requirements by automatic means if option S4.3.1 were taken, no truck manufacturer chose to comply with the 'rollover' requirements of Standard No. 208 via the Standard No. 216 option. Rather, seat belts were installed on all large trucks.; Sincerely, Frank Berndt, Chief Counsel |
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ID: aiam3793OpenMr. J. N. White, 1300 California Drive, Rolla, MO 65401; Mr. J. N. White 1300 California Drive Rolla MO 65401; Dear Mr. White: This is in response to your January 3, 1984, letter to Roger Fairchil of this office regarding Federal Motor Vehicle Safety Standard No. 111 (Rearview Mirror Systems). You have requested information on the applicability of that standard, particularly in regard to aftermarket mirrors.; FMVSS 111 is a rule or regulation (the terms are generally use interchangeably) establishing requirements for rearview mirrors on new passenger cars, multipurpose passenger vehicles, trucks, buses, school buses, and motorcycles. Aftermarket mirror manufacturers do not have to certify compliance with our standards. However, the addition of an aftermarket mirror to a motor vehicle may be subject to certain legal requirements. Section 108(a)(2)(A) of the National Traffic and Motor Vehicle Safety Act prohibits any manufacturer, distributor, or dealer of motor vehicles or motor vehicle equipment, or any motor vehicle repair business from knowingly rendering inoperative any device or element of design installed on a vehicle in compliance with a safety standard. Thus, manufacturers, distributors, dealers, and repair businesses cannot remove a rearview mirror installed as original equipment in compliance with our standard and replace that mirror with a noncomplying aftermarket mirror. Replacement by other individuals or organizations or replacement with a complying aftermarket mirror would be permitted.; With regard to your final question as to requirements applicable to th use of non-glare glass in mirrors, this agency issued on November 6, 1978, a notice of proposed rulemaking on possible upgrading of rearview mirror requirements (copy enclosed). One part of this proposal would establish image luminance criteria for rearview mirrors. The agency has not yet determined whether this requirement should be implemented, and no action is imminent on that proposal.; Sincerely, Frank Berndt, Chief Counsel |
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ID: aiam1401OpenHonorable Leonor K. Sullivan, House of Representatives, Washington, DC 20515; Honorable Leonor K. Sullivan House of Representatives Washington DC 20515; Dear Mr. Sullivan: In response to your February 11, 1974, request in behalf of constituent, Mr. Frank Mills of Saint Louis, I would like to discuss the legal implications of modifications to the ignition interlock system on 1974 model passenger cars. I am not familiar with the booklet to which Mr. Mills refers.; The interlock is one part of Standard 208, which like any other safet standard issued under the National Traffic and Motor Vehicle Safety Act of 1966, applies to new vehicles only. Once a vehicle is sold for purposes other than resale and the buyer takes delivery, he may modify the system or legally have the system modified by an automobile repair service to accommodate circumstances, such as physical incapacity, which make use of the belts unwise or inconvenient.; Whether or not a dealer's disconnection of an interlock system unde any given specified set of circumstances would be legally permitted is a conclusion which the courts would determine if called upon to decide such an issue. The position of this agency is that any act by a dealer to disconnect an interlock system which could be related to a sales transaction or the introduction into interstate commerce of a motor vehicle is prohibited. In this respect, we support H.R. 5529 which would prohibit any motor vehicle manufacturer, distributor, dealer, or repair business from removing or rendering inoperative any Federally-required safety equipment, including interlocks, from new or used vehicles. The prohibition would not apply to vehicle owners.; I have taken the liberty of forwarding a copy of this letter to Mr Mills at his St. Louis address to assure receipt of the information by February 21, 1974.; Sincerely, Lawrence R. Schneider, Chief Counsel |
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ID: aiam3578OpenRegal Tire Corporation, 4309 County Line Road, Chalfont, PA 18914; Regal Tire Corporation 4309 County Line Road Chalfont PA 18914; Dear Sir: At the request of the office of the Honorable Peter Peyser, M.C., w are writing this letter to you to explain the significance of certain items of information molded on the sidewall of new tires.; Part 574, *Tire identification and recordkeeping* (49 CFR 574) requires that each new tire to be sold in the United States have a serial number molded on one of its sidewalls. That number identifies the tire's manufacturer, date of manufacture, and size. This information is designed to ensure the proper identification of all tires subject to a recall by the manufacturer for correction of a safety-related defect or of a failure to comply with a safety standard. The serial number is not a guarantee of quality or of compliance with any safety standard.; Each new tire is also required by Federal Motor Vehicle Safet Standards Nos. 109, *New pneumatic tires*, and 119, *New pneumatic tires for vehicles other than passenger cars* (49 CFR 571.109 and 571.119), to have the symbol 'DOT' appear on one of its sidewalls. This symbol is a certification by the tire's manufacturer that the tire fully complies with all requirements of the applicable safety standard. The symbol does not guarantee the quality of a tire in areas of performance unregulated by the safety standards.; Neither the serial number nor the DOT symbol constitute representation that a tire is free from any safety- related defect.; If you have any questions regarding these matters, please contact me. Sincerely, Frank Berndt, Chief Counsel |
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ID: aiam2539OpenMr. Jeffrey L. Link, Supervisor, Product Safety, Safety and Legislation Department, U.S. Suzuki Motor Corporation, 13767 Freeway Drive, Santa Fe Springs, California 90670; Mr. Jeffrey L. Link Supervisor Product Safety Safety and Legislation Department U.S. Suzuki Motor Corporation 13767 Freeway Drive Santa Fe Springs California 90670; Dear Mr. Link: This responds to your February 23, 1977, letter asking whether thre proposed labeled satisfy the requirements for label identification found on Standard No. 120, *Tire Selection and Rims for Motor Vehicles Other Than Passenger Cars*.; The National Highway Traffic Safety Administration (NHTSA) does no issue advance approval of compliance by manufacturers with motor vehicle safety standards or regulations. The agency, however, will give an informal opinion as to whether your sample labels appear to comply with the requirements of Standard No. 120. A review of the labels you supplied indicates that you have used a different format than illustrated in our notice of February 7, 1977 (42 Federal Register 7140). For example, the amended Standard No. 120 does not require the words 'with the tires listed below' or even the word 'with' before the tire size. The deletion of such superfluous words from the label requirements of Standard No. 120 resulted from comments by manufacturers, particularly motorcycle manufacturers, that unnecessary word needlessly increase the size of the label.; The example of label information shown in S5.3 of the standard i intended only as a guide to manufacturers. A manufacturer can vary the illustrated format somewhat as long as the requirements of S5.3 are satisfied. Since the additional words on your label do not obfuscate the certification statement, the labels appear to comply with the requirements of Standard No. 120 and Part 567.; Sincerely, Frank Berndt, Acting Chief Counsel |
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ID: aiam2430OpenMr. Kerry G. Lund, United Recreational Products, Inc., Country Road & Highway 35, Webster, WI 54893; Mr. Kerry G. Lund United Recreational Products Inc. Country Road & Highway 35 Webster WI 54893; Dear Mr. Lund: This responds to your July 16, 1976, request for information on th requirements for a manufacturer of a light utility trailer which is designed to carry snowmobiles. I regret that we have not responded sooner.; The information you request appears in Title 49 of the Code of Federa Regulations, and I enclose an information sheet which explains how this material may be acquired.; Part 566, *Manufacturer Identification (49 CFR Part 566), specifie identification information which must be submitted to the NHTSA by manufacturers of vehicles and equipment regulated by our standards.; Part 567, *Certification* (49 CFR Part 567), specifies the content an location of the certification label or tag which must be attached to motor vehicles regulated by our standards.; At this time the only Federal safety standards applicable to al trailers are Standard No. 108, *Lamps, Reflective Devices, and Associated Equipment*, and Standard No. 120, *Tire and Rim Selection for Vehicles Other Than Passenger Cars*. The enclosed information sheet also explains how to acquire those regulations.; Standard No. 121, *Air brake systems*, became effective on January 1 1975, in the case of trailers which the manufacturer has decided to equip with air brakes. Thus trailers which you manufacture on or after January 1, 1975, which utilize air brakes must meet the air brake standard.; After you have reviewed the regulations I have referred to, pleas contact me if you have any further questions.; Yours truly, Frank A. Berndt, Acting 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: aiam1810OpenMr. E. J. O'Reilly, Vice President, Sales, YKK ZIPPER (U.S.A.), Inc., Illinois Division, 2165 Shermer Road, Northbrook, IL, 60062; Mr. E. J. O'Reilly Vice President Sales YKK ZIPPER (U.S.A.) Inc. Illinois Division 2165 Shermer Road Northbrook IL 60062; Dear Mr. O'Reilly: This is in response to your letter of February 13, 1975, in which yo ask whether zippers fall under the purview of Federal Motor Vehicle Safety Standard No. 302.; S4.1 of the standard states that the following components of passenge cars, multipurpose passenger vehicles, trucks, and buses must meet its requirements:; >>>Seat cushions, seat backs, seat belts, headlining, convertible tops arm rests, all trim panels including door, front, rear, and side panels, compartment shelves, head restraints, floor coverings, sun visors, curtains, shades, wheel housing covers, engine compartment covers, mattress covers, and any other interior materials, including padding and crash-deployed elements, that are designed to absorb energy on contact by occupants in the event of a crash.<<<; To the extent that a zipper is a part of any of these components, i would fall within the ambit of the standard. While recreational vehicles are not currently covered by Standard No. 302, the National Highway Traffic Safety Administration issued on November 15, 1974, a Notice of Proposed Rulemaking to extend the coverage of the standard to include recreational vehicles (copy enclosed).; You should also be aware that other rulemaking relevant to the coverag of the standard is underway and will soon be published in the *Federal Register*. For this reason, we recommend you subscribe to either the Government Printing Office Safety Standard subscription service or an equivalent commercial service as detailed in the enclosure.; Sincerely, James C. Schultz, Chief Counsel |
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ID: aiam1492OpenMr. Peter Dakin, 733 spartan Drive, Rochester, MI 48063; Mr. Peter Dakin 733 spartan Drive Rochester MI 48063; Dear Mr. Dakin: This is in response to your letter of May 4, 1974, requestin information concerning Federal safety standards applicable to the assembly of kit cars.; The National Traffic and Motor Vehicle Safety Act of 1966 prohibits th manufacture for sale or introduction into interstate commerce of any motor vehicle that does not comply with all applicable Federal motor vehicle safety standards. therefore, if the vehicle you are building is going to be used as a means of transportation on the road, it must be certified as conforming with all applicable safety standards. The mere use of a vehicle on public highways constitutes an introduction into interstate commerce and is prohibited unless compliance with the safety standards has been achieved.; Part 567.4(g)(1)(ii) of the certification regulations provides th producer of the kit with an option as to whether or not he certifies that the vehicle will comply with all applicable safety standards if completed according to his instrucitons. We would urge you to avoid undertaking the assembly of a kit that does not give assurance as to its ultimate ability to comply. If the producer of the kit takes the responsibility of certifying the completed vehicle, you as the asembler of the vehicle must exercise reasonable care in following the instructions he provides.; For your information I have enclosed a sheet entitled 'Where to Obtai Motor Vehicle Safety Standards and Regulations' which will direct you to the proper source for obtaining a copy of the safety standards and regulations.; Yours truly, Richard B. Dyson, Assistant 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.