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: 8393aOpen Mr. Berkley C. Sweet Dear Mr. Sweet: This responds to your letter requesting definitions of primary, preprimary, and secondary school students. You write in response to our July 28, 1992 letter to you in which we state that the National Traffic and Motor Vehicle Safety Act, 15 U.S.C. 1581, et seq. (Safety Act), defines a school bus as a vehicle that is "likely to be significantly used for the purposes of transporting primary, preprimary, or secondary school students to or from such schools or events related to such schools" (emphasis added). The terms primary, preprimary, and secondary school are not defined in the Safety Act or in the legislative history of the Act. However, NHTSA has historically interpreted "preprimary school" to refer to kindergarten, nursery schools and Head Start facilities. "Primary school" refers to elementary school, and "secondary school" refers to high school. I have enclosed a copy of our March 20, 1990 letter to Mr. Cadwallader Jones that discusses whether various institutions (e.g., church schools and colleges) are considered "schools" under the Safety Act. The various states may have their own definitions of a "school" for determining the use requirements for school vehicles. Therefore, you should check with the state where questions of school vehicle use are at issue. I hope the above information will be of assistance to you. If you have any further questions regarding this matter, please feel free to contact Walter Myers of my staff at this address or at (202) 366-2992. Sincerely,
John Womack Acting Chief Counsel Enclosure ref:571#VSA d:6/3/93 |
1993 |
ID: nht72-6.45OpenDATE: 06/06/72 FROM: AUTHOR UNAVAILABLE; E. T. Driver; NHTSA TO: International Houseing Incorporated TITLE: FMVSR INTERPRETATION TEXT: This is to acknowledge your letter of May 19, 1972, regarding tire identification and recordkeeping. Regulation Part 574 requires a vehicle manufacturer to maintain a record of tires on each vehicle shipped to a dealer and requires that he maintain a record of the name and address of the first purchaser of the vehicle for a period of three years. The purpose, of course, is to enable him to locate tires in the event of a recall. The name and address of the purchaser is provided by the dealer. The manufacturer is not required by the regulation to record each identification number for each tire, but may do so by group or category. There is a strong possibility that all tires on one vehicle will be of the same brand and will have the same identification number. The manner in which a manufacturer chooses to maintain the tire records is optional and the dealer would be expected to cooperate in his system of recording data. It is primarily a matter of agreement between manufacturer and dealer. In the event the original tires on a vehicle are changed by the dealer prior to sale, he must report the new tire identification numbers and the purchaser's name and address to the manufacturer of the tires sold with the vehicle. We note that your letter refers to registration of serial number rather than identification number. It is the letter that is subject to the regulation. We trust this information answers your questions. |
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ID: 9758Open Ms. Denise Davis Dear Ms. Davis: This responds to your letter asking for help in a matter involving window tinting on your car. I apologize for the delay in responding. You explain in your letter that you asked a window tinting store for a sticker showing that the tint on your windows met Georgia law. The store informed you that it cannot issue you a sticker because your windows only allow 20 percent sunlight through, and the new law requires 35 percent. To get a sticker, you would have to remove the tint, which you explain will be costly. You also state that your windows were tinted seven years ago when you purchased your car, and at the time you had your windows tinted, you were "not breaking any law." I regret that we cannot help you pay to have the tint removed. The primary purpose of this agency is to regulate the manufacture and sale of new motor vehicles and new motor vehicle equipment. We have no authority to provide funds to citizens to help them correct problems with their vehicles or equipment. Please bear in mind that the "35 percent" law was adopted by Georgia to regulate the operation of vehicles. Thus, we suggest that you contact the Georgia Department of Motor Vehicles for information about this matter. We appreciate your efforts to reduce the tint on your vehicle and are sorry that we are unable to assist you. If you have any other questions, please contact Mr. Marvin Shaw of my staff at (202) 366-2992. Sincerely,
John Womack Acting Chief Counsel ref:205 d:8/9/94
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1994 |
ID: 77-4.35OpenTYPE: Interpretation-NHTSA DATE: November 11, 1977 FROM: James Tydings -- Specifications Engineer, Thomas Built Buses, Inc. TO: Roger Tilton -- Office of the Chief Counsel, U.S. Department of Transportation TITLE: Re "Head Start" Buses ATTACHMT: Attached to letter dated 12-21-77 from Joseph J. Levin, Jr. to James Tydings; Also attached to letter dated 3-8-91 from Paul Jackson Rice to Ron Marion (A37; VSA 102(14) Part 571.3); Also attached to letter dated 5-10-82 from Frank Berndt (Signature by Stephen P. Wood) to Martin V. Chauvin; Also attached to letter dated 5-12-81 from Frank Berndt to Doris Perlmutter; Also attached to letter dated 6-11-90 from Ron Marion to Paul Jackson Rice (OCC 4915) TEXT: It is our understanding that the latest definition of a school bus was issued on December 23, 1975, with an effective date of October 27, 1976. This definition was published in the Federal Register Vol. 40, No. 251, Wednesday, December 31, 1975. In the preamble of this notice, the reference is made to the (The Act)- Motor Vehicle and Schoolbus Safety Amendments of 1974. This Act included a definition of a "school bus" wherein this definition used the word "preprimary" as referring to students. If this be true, are we correct that "Head Start" buses used to transport preprimary students to the Head Start Programs, funded by HEW, are school buses as defined in the above notice, and are subjected to all of the Federal Motor Vehicles Standards applicable to school buses? Thanking you in advance, we remain sincerely yours. |
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ID: 9439Open Sgt. Dennis Platt, Supervisor Dear Sgt. Platt: This responds to your letter of December 7, 1993, requesting confirmation of a statement made by a NHTSA officer that there is no federal regulation that requires replacement of a deployed air bag. I am enclosing two letters that explain legal obligations to replace air bags which have been deployed. The first letter, dated January, 19, 1990, is to Ms. Linda L. Conrad. The second letter, dated March 4, 1993, is to Mr. Robert A. Ernst. As explained in those letters, Federal law does not require replacement of a deployed air bag in a used vehicle. In addition, there is no Federal law that prohibits selling a used vehicle with a supplemental restraint that is inoperable because of a previous deployment. However, our agency strongly encourages dealers and repair businesses to replace deployed air bags whenever vehicles are repaired or resold, to ensure that the vehicles will continue to provide maximum crash protection for occupants. Moreover, a dealer or repair business may be required by state law to replace a deployed air bag, or be liable for failure to do so. I am also enclosing a copy of the information sheet referred to in the two letters discussed above. I hope you find this information helpful. If you have any other questions, please contact Mary Versailles of my staff at this address or by phone at (202) 366-2992. Sincerely,
John Womack Acting Chief Counsel Enclosures ref:208 d:12/30/93 |
1993 |
ID: nht71-5.5OpenDATE: 11/22/71 FROM: AUTHOR UNAVAILABLE; Richard B. Dyson; NHTSA TO: Mr. James Eckstein TITLE: FMVSS INTERPRETATION TEXT: This is in reply to your letter of August 27, 1971, which was forwarded to this office October 20, 1971, by the Federal Trade Commission, regarding Government specifications for retreaded tires. You refer to problems you believe result from "out of roundness;" specifically, abnormal wear and blowouts at normal boulevard and highway speeds. You wish to determine whether this problem results from "too lenient" Government requirements, or whether "manufacturers are negligent." Out-of-roundness can occur in a retreaded tire for numerous reasons, and its presence does not necessarily indicate negligence on the part of the manufacturer. Moreover, while an out-of-round tire may affect vehicle handling it generally does not blow out at normal boulevard or even highway speeds, as a result of the out-of-round condition. Thus, a blow out in an out-of-round tire could have resulted from other factors. Many tire dealers, in addition, have machines that can eliminate out-of-roundness by cutting off excess tread. With reference to Federal regulations of retreaded tires, the first such regulation will become effective January 1, 1972. This regulation, Motor Vehicle Safety Standard No. 117, "Retreaded Pneumatic Tires," specifies size and performance requirements for retreaded tires for use on passenger cars. These requirements are similar to those that have been applicable to new passenger car tires since January 1, 1968. None of these requirements specifically concern "out-of-roundness." We do not have evidence that this characteristic, by itself, is a safety problem.
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ID: nht93-8.1OpenDATE: November 8, 1993 FROM: Herman Myburgh -- Executive Vice-President, Allvan Corporation TO: John Womack -- NHTSA TITLE: Re: FMVSS Part 571.108 on conspicuity striping on truck ATTACHMT: Attached to letter dated 11/22/93 from John Womack to Herman Myburgh (A41; Std. 108) TEXT: We are manufacturers of curtainsided trailers where the curtain material wraps around the side rails of the trailer. Currently there are no retroreflective tape manufacturer who makes a tape that can stick to or can be RF. welded to the curtain material itself. Could we attach the conspicuity striping to the trailer frame rail itself in such a manner that it will still comply with the latest amendment of "anywhere from 375mm to 1525mm above the ground"? This will be in the same manner as it will probably be applied to container chassis. Your response to this at your earliest convenience will be appreciated. |
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ID: nht94-5.11OpenTYPE: INTERPRETATION-NHTSA DATE: December 16, 1994 FROM: Mark Warlick -- FMVSS Coordinator, Four Winds International Corporation TO: Philip Recht -- Chief Counsel, NHTSA TITLE: None ATTACHMT: ATTACHED TO 2/27/95 LETTER FROM PHILIP R. RECHT TO MARK WARLICK (REDBOOK (2); PART 302) TEXT: This letter concerns a question of what legal documentation is required for Federal Motor Vehicle Safety Standard No. 302 compliance. Four Winds International Corporation is a manufacturer of Class A and Class C motorhomes. I am in process of organizing our FMVSS letters of compliance from our vendors that supply our interior materials. I have included a sample of a letter that I hav e received from a vendor. Does this letter meet NHTSA requirements for certification of compliance for FMVSS No. 302 as far as proof of compliance by Four Winds? If this letter does not contain sufficient information to prove compliance by Four Winds, can you send me a sample of what we need in our records per vendor to show compliance? enclosure December 9, 1994 We have tested the panel from Northland Enterprise that was made with COR63-AX-40. We used the MVSS302 flame test, and obtained a flame rating of 0.64 inch per minute. If you have any questions regarding this information or on any products in general, please contact us. Sincerely, INTERPLASTIC CORPORATION Rey de la Rosa Group Leader Physical Testing |
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ID: 16845.wkmOpenMr. Harold E. Hutchings Dear Mr. Hutchings: This responds to your letter following up on your earlier request for information under the Freedom of Information Act (FOIA), relating to this agency's rulemaking actions on antilock braking systems (ABS) for light duty vehicles. I apologize for the delay in responding. Your letter discusses problems you have encountered obtaining information on ABS. In your FOIA request, you had asked for, among other things, "a report you received from the General Motors Engineers [sic] who reported after extensive investigations the problems with A.B.S. were unresolvable." In response, Ms. Coleman of my staff stated that the agency was unable to locate this specific report. However, she stated that material provided by General Motors Corporation (GM) to the agency pertaining to the ABS rulemaking can be obtained from the agency's Technical Reference Library (which has since been renamed Technical Information Services (TIS)) , and provided the docket number for the ABS action (Docket No. 93-94). According to your letter, you contacted TIS and received a list of commenters and other entries to that docket. You said you then contacted the National Technical Information Service "regarding those numbers" but were informed that you need to provide "proper D.O.T. and other numbers" to obtain the information you seek. As Ms. Coleman wrote you previously, the agency was not able to locate the GM report in our files. However, all material submitted to the agency by GM pertaining to the ABS rulemaking action is listed on the index you received from TIS. You may obtain copies of any document listed in the index by contacting TIS and referencing the document number shown on the listing. You may contact TIS by visiting, calling or writing to that office at the following address: NHTSA, Room 5108, 400 Seventh St., S.W., Washington D.C. 20590. I hope this information has been helpful. Sincerely, |
1998 |
ID: nht73-1.8OpenDATE: 08/20/73 FROM: AUTHOR UNAVAILABLE; R. B. Dyson; NHTSA TO: Renault, Inc. TITLE: FMVSS INTERPRETATION TEXT: This is in reply to your letter of August 1, 1973, asking for clarification of S5.2.1 and S6.9 of Standard No. 105a. You interpret the parking brake test as allowing "the vehicle to slide down the 30% incline (because of its weight) as long as the wheels remain locked". The parking brake must hold the vehicle on a 30% grade for 5 minutes. If vehicle weight distribution is such that the limit of traction is exceeded and the vehicle slides down the incline, no noncompliance would be indicated unless the parking brake failed to lock the wheels. No skid number is specified for the "clean, dry, smooth, portland cement concrete" incline surface specified in S6.9. Yours truly, August 1, 1973 Lawrence R. Schneider -- Chief Counsel, Nat. Highway Traffic Safety Admins. SUBJECT: FMVSS 105a - Docket 70-27, Notice 8 Dear Mr. Schneider: Regie Nationale des Usines Renault would like to request a clarification regarding section S.5.2.1. and S.5.2.2.1 of the above Docket. It is our understanding that in order for the parking brake to comply with these paragraphs, the wheels of the vehicle must remain locked, but the vehicle may slide down the 30% incline (because of its weight) as long as the wheels remain locked. We would appreciate receiving a written confirmation of our interpretation. In addition, we would appreciate the NHTSA informing us of the skid number of the "clean, dry, smooth, Portland cement concrete" referred to in paragraph S.6.9. Thank you for your cooperation and consideration. Very truly yours, RENAULTINC --[Illegible Words] for Francois Louis, Manager, Technical Standards Dept. |
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.