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
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ID: nht68-3.46OpenDATE: 07/31/68 FROM: AUTHOR UNAVAILABLE; J. R. O'Gorman; NHTSA TO: Associazione Nazionale Fra Industrie Automobilistiche TITLE: FMVSS INTERPRETATION TEXT: Thank you for your letter of June 3 to the National Highway Safety Bureau asking "whether the solution given in the enclosed drawing N. 591-1559 of Ferrari is in line with the requirements" of Federal motor vehicle safety standard No. 211. This standard states that "wheel nuts, hub caps, and wheel discs for use on passenger cars . . . shall not incorporate winged projections". The Ferrari plan appears to incorporate such a projection, even though it is recessed. Accordingly the proposed solution by Ferrari does not meet the requirements of Federal standard No. 211. ASSOCIAZIONE NAZIONALE FRA INDUSTRIE AUTOMOBILISTICHE U.S. Department of Transportation Federal Highway Administration National Highway Safety Bureau June 3 1968 Motor Vehicle Safety Standard n. 211 Reference is made to your letter of December 21st 1967 and we wish to thank you very much for the explanations about the standard N. 211. Further we would appreciate it very much your letting us know whether the solution given in the enclosed drawing N. 591-1559 of Ferrari is in line with the requirements concerning "wheel nuts, hub caps and wheel discs". Thanking you in advance, we remain Faithfully Yours, (Illegible Word) Direttore (Francesco Palazzi) |
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ID: nht90-1.2OpenTYPE: INTERPRETATION-NHTSA DATE: 01/01/90 EST FROM: DAVID R. MARTIN TO: NHTSA OFFICE OF PUBLIC AFFAIRS TITLE: NONE ATTACHMT: ATTACHED TO LETTER DATED 05/17/90 FROM STEPHEN D. WOOD -- NHTSA TO DAVID R. MARTIN; REDBOOK A35; STANDARD 301; STANDARD 217 TEXT: I have which to me, is a very urgent and important question. To preface my question, I'd like to tell you that I was in the Navy in the early 1940's and was aboard a ship that exploded, and burned fiercely when strucks by a tarpedo. Unfortunately, at the present time, I'm in the custody of the Florida Department of Corrections, the reason for which I do not believe is pertenant to my question. The Department of Corrections operates a huge fleet of vans. The inmates of the system, when transported in these vans, rear handcuffs, waist-chains, and leg-irons. The vans themselves have steel mesh welded to all the windows, and a steel mesh part ition between the passenger compartment and the driver area. The vans are also padlocked from the outside, when in transit. Having had first hand experience with a fuel (Illegible Word) fire, I am wondering how could the compliance by the department of Corrections with the Federal Motor Vehicle Safety Standard 301 be ascertained? Is thero any way that your department can verify compliance? I would appreciate your checking this out for me, and advising me as to your findings. (Illegible Lines) |
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ID: nht72-6.53OpenDATE: 04/28/72 FROM: AUTHOR UNAVAILABLE; E.T. Driver; NHTSA TO: Tiny's Tire Center TITLE: FMVSR INTERPRETATION TEXT: Thank you for your recent letter regarding tire identification and recordkeeping, and your suggestions for promotion of safety on the highways. As you know the Congress set forth the requirements for tire identification and recordkeeping as a part of the National Traffic and Motor Vehicle Safety Act of 1966, amended May 22, 1970. The Safety Act specifically places responsibility for tire identification and recordkeeping upon the (Illegible Words) with the assistance of dealers and distributors. We believe Regulation Part 574 implements this mandate of the Congress in an effective and workable manner. Hopefully it will prove to be a protective measure to the great majority of conscientious industry members who are maintaining high safety standards in their products. This Administration, by authority of the National Highway Safety Act of 1966, is also deeply involved in a program of traffic safety standards. Periodic Motor Vehicle Inspection is the first standard in the program. Details concerning the standard are contained in the Highway Safety Program Mannual Volume I, copy enclosed. Another standard in the program entitled "Alcohol in Relation to Highway Safety" is described in the Highway Safety Program Mannual Volume 8, copy enclosed. As you know, State and local enforcement plays a major role in the success of this type of program. We acknowledge, however, that much work at the Federal level is yet to be done in this area of safety. Standardizing automotive switches and controls is related to accident avoidance and is covered in the series-100 of Federal motor vehicle safety standards. Please note Standards No. 101 and No. 102 in the enclosed publication. With regard to consumer information and protection, special attention is being given to this subject by the White House's Office of Consumer Affairs. We are enclosing a pamphlet that contains an index of Federal publications on how to buy and use consumer products. Your interest in consumer safety and protection is very much appreciated. |
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ID: nht72-6.24OpenDATE: 11/16/72 FROM: AUTHOR UNAVAILABLE; R. B. Dyson; NHTSA TO: Nippondenso Company, Ltd. TITLE: FMVSS INTERPRETATION TEXT: This is in reply to your letter of October 25, 1972, telling us that you have tested turn signal flashers in accordance with Motor Vehicle Safety Standard No. 108a, which you believe is a more severe test than Standard No. 108, and asking our views as to whether you should retest in accordance with Standard No. 108. The important question is not whether one standard establishes a more severe test than another, but whether a flasher meets all performance requirements applicable to it on the date of its manufacture. The legal obligation of a manufacturer is to insure that it does. The requirements currently applicable to flashers are those of Standard No. 108. It is true that Standard No. 108a has been "repealed" and No. 108 "reinstated". The reason for this action is a judicial decision that the NHTSA did not provide adequate public notice and opportunity to comment on the flasher requirements in Standard No. 108a. However, the NHTSA has proposed that the flasher performance requirements of Standard No. 108a be re-adopted, and is offering the public an opportunity to comment. I enclose a copy of the notice for your information. |
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ID: nht90-4.14OpenTYPE: Interpretation-NHTSA DATE: September 18, 1990 FROM: Erika Z. Jones -- Mayer, Brown & Platt TO: Stephen P. Wood -- Assistant Chief Counsel, NHTSA TITLE: Re Fidelity Tire notification ATTACHMT: Attached to letter dated 12-6-90 to E.Z. Jones from S.P. Wood (A36; Std.119) TEXT: This letter confirms our telephone conversation of today in which you advised me that NHTSA is in receipt of notification dated January 5, 1990 from Fidelity Tire Manufacturing Company of Natchez, Mississippi regarding their manufacture of a tire, size P 155/8ODl3 Load Range C (41 psi and 1047 lb. load carrying capacity), with a specified wheel rim of 4 1/2 JB, 13". You advised me that the notification from Fidelity contains all the information necessary to comply with the notification requirements of Fe deral Motor Vehicle Safety Standard 119 (S.5) for tires and rims not listed in the publication of a recognized tire and rim association. Please advise me as soon as possible if my understanding of our conversation is not correct, as our client who has purchased these tires from Fidelity, will be proceeding to offer for sale a product employing these tires in reliance on our understanding that the notification requirements have been satisfied. Thank you for your attention to this matter. |
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ID: nht73-3.13OpenDATE: 01/22/73 FROM: AUTHOR UNAVAILABLE; R. B. Dyson; NHTSA TO: Wesbar Corporation TITLE: FMVSS INTERPRETATION TEXT: This is in reply to your letter of January 3, 1973, to Mr. Schneider concerning Motor Vehicle Safety Standard No. 108. Your first question is whether the standard requires items of lighting equipment to be marked according to SAE Standard J759a. The answer is no. A manufacturer, at his option, may mark equipment items with the symbol DOT as a certification of compliance with Standard No. 108. Standard No. 108 neither prohibits nor requires other marking of equipment. The NHTSA proposed in 1972 that equipment be marked in a manner somewhat similar to J759a but no definitive action has been taken on the proposal. You also asked whether a clearance lamp could be mounted at 45 degrees to serve the functions of both a clearance and side marker lamp, and whether it must bear the SAE designation "PC" indicating its combination function. Your understanding is correct, that a combination lamp mounted at 45 degrees is permissible if it is successfully tested at that mounting angle for conformance to both clearance and side marker requirements. The designation "PC" is not a current requirement of Standard No. 108 but has been proposed as the required marking symbol in the rulemaking action referred to earlier. |
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ID: nht73-3.19OpenDATE: 02/06/73 FROM: AUTHOR UNAVAILABLE; Richard B. Dyson; NHTSA TO: Mr. Robert L. Scates TITLE: FMVSS INTERPRETATION TEXT: This is in reply to your letter of January 6, 1973, requesting information on requirements regarding the manufacture of truck-mounted campers. You specifically mention requirements dealing with wiring. There are several Federal requirements applicable to campers. Campers are items of motor vehicle equipment under the National Traffic and Motor Vehicle Safety Act (15 U.S.C. 1381 et seq.) and are required to conform to certain motor vehicle safety standards and regulations. Briefly, each camper must meet requirements applicable to the glazing materials (glass and plastics used in windows, doors, and interior partitions) used in the camper (Federal) Motor Vehicle Safety Standard No. 205, "Glazing Materials", 49 CFR 571.205). Each slide-in camper must, in addition, have affixed to it a label that indicates among other things its loaded weight. (Federal Motor Vehicle Safety Standard No. 126, "Truck-Camper Loading", 49 CFR 571.126). All campers must also be certified in accordance with Section 114 of the National Traffic and Motor Vehicle Safety Act (15 U.S.C. 1403) as conforming to applicable standards. Each camper manufacturer must submit certain information concerning his company pursuant to NHTSA regulations, "Manufacturer identification" (49 CFR Part 566). You may obtain copies of NHTSA standards and regulations as explained on the enclosure. We understand that certain states also have requirements, including requirements for wiring, that apply to campers. Information regarding these requirements should be obtained from State authorities. Trade associations that represent recreational vehicle manufacturers may be of help in obtaining this information. ENC. |
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ID: nht78-3.49OpenDATE: 04/24/78 FROM: AUTHOR UNAVAILABLE; John Womack; NHTSA TO: Alliance of American Insurers TITLE: FMVSR INTERPRETATION TEXT: This is in response to your letter of March 22, 1978, requesting that the National Highway Traffic Safety Administration (NHTSA) interpret "primary place of business" under 49 CFR Part 580 to include regional offices and other places of business where companies' records are customarily maintained. It is our opinion that "primary place of business" includes, in the case of a business with multiple offices, a regional or local office where transactions involving the subject vehicles took place and the records are maintained, in addition to the home office or headquarters of the business. For example, if a vehicle is repossessed by an insurance company that has its home office in New York, but the regional office in Chicago handled and retained all the paperwork on the repossessed vehicle, then the Chicago office would be the primary place of business for that transaction and the odometer disclosure statements should be retained in the Chicago office. The office that the purchaser dealt with would be the one he would contact if a problem arose at a later time. Therefore, it would be the logical office to maintain the records. If, however, the Chicago office handled the paperwork but upon completion forwarded it to the New York office, the New York office, as the repository for all paperwork, would be the primary place of business and odometer statements, like all other documents should be forwarded to that office. The place of retention, like the manner of retention, must be consistent so that systematic retrieval is possible.
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ID: nht94-1.52OpenTYPE: Interpretation-NHTSA DATE: February 11, 1994 FROM: Jerry L. Steffy -- Triumph Designs, Ltd. TO: Taylor Vinson -- NHTSA TITLE: None ATTACHMT: Attached to letter dated 3/16/94 from John Womack to Jerry L. Steffy (A42; Std. 108; Part 555) TEXT: Since I faxed you with my question regarding FMVSS 108 and ECE Reg. 20, I received Part 555 of 49 CFR from Luke Loy. 555.5 implies that we could apply for an exemption from FMVSS 108 for this headlamp since there exists "an equivalent overall level of motor vehicle safety." This is of course, if NHTSA recognizes the worthiness of the testing under ECE Reg. 20. This exemption would only be for the first model year as afterwards we will change to a headlamp already FMVSS 108. Can you please confirm for the if this is a route we can employ in this instance? Best regards. 2-10-94 fax from J.L. Steffy to Taylor Vinson: Dear Taylor: Luke Loy suggested that I contact you with a specific query I have. Recently, in Canada, we were able to use ECE Reg. 20 in lieu of FMVSS 108 for a particular headlamp system use. Is it possible to substitute ECE 20 for FMVSS 108 in the states in some instances? Of course the majority of our suppliers fulfill testing according to FMVSS 108 however, there are individual exceptions. Some cases may require significant investment in order to have individual cases comply, so it is important to know. Best regards |
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ID: nht72-1.12OpenDATE: 04/25/72 FROM: AUTHOR UNAVAILABLE; R. B. Dyson; NHTSA TO: Nissan Motor Co., Ltd. TITLE: FMVSS INTERPRETATION TEXT: This is in reply to your letter of April 5 to Mr. Schneider asking for an interpretation of Standard No. 106. You ask whether it is permissible to use a rubber protector on a brake nose which masks in part the identification marking required by Standard No. 106. SAE Standard J40b, Automotive brake Hoses, incorporated by reference in Standard No. 106, requires hose working to be permanent in nature. Therefore, use of this protector is permissible, provided that its rubbing effect, if any, does not oblitorate in time the required marking. You have also asked whether you may conduct the whip test with the rubber protector removed. We have no objection to this method of conducting the whip test. Standard No. 106 is silent as to how the test may be conducted. Paragraph 57.1.4 of our proposal to amend Standard No. 106 (Docket No. 1-5; Notice 7, 36 F.R. 5855, March 30, 1971) represents our view that "protective armor" should be removed for the fatigue test, and you may interpret this as including the rubber protectors also. YOURS TRULY, NISSAN MOTOR CO., LTD. April 5, 1972 Lawrence Schneider National Highway Traffic Safety Administration SUBJECT: Interpretation of MVSS 106. We would like to have your interpretation regarding MVSS 106-Hydraulic Brake Hoses, (1) whether or not we may use the rubber protector which would hide the marking on brake hose in part. (Protector itself is not glued, but envelopes the hose tightly so it could be movable when relatively strong force is applied.) (2) whether or not we may conduct the whip test with the rubber protector removed. Your assistance in this matter would be greatly appreciated. Satoshi Nishibori Engineering Representative Liaison Office in U. S. A. |
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.