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: nht78-3.47OpenDATE: 04/19/78 FROM: AUTHOR UNAVAILABLE; John Womack; NHTSA TO: Cary C. Boyden TITLE: FMVSR INTERPRETATION TEXT: This is in response to your letter of February 22, 1978, concerning the Federal odometer requirements. The question you raised was whether the lessor can leave the transferee's name and address on the odometer disclosure statement blank in cases where the transferee is a bank who has not yet determined whether the vehicle will be leased or the subject of a secured lending arrangement. As defined in 49 CFR @ 580.3, "Transferee" means "any person to whom the ownership in a motor vehicle is transferred by purchase, gift, or any means other than by creation of a security interest." Therefore, if the bank is taking possession of the vehicle in order to lease it, the lessor should indicate that the bank is the transferee. If the bank is taking possession of the vehicle in order to make it the subject of a secured lending arrangement, the bank's customer, and not the bank, should appear on the disclosure statement as transferee. You indicated that additional paper work would result if the bank were required to be listed as the transferee in both of the above situations until it decided how to dispose of the vehicle. As a result, you suggested that it be acceptable to list as transferee the bank or its customer as their respective interest may appear. You stated that "this alternative would allow the bank either to retain the statement on its own behalf or to forward the disclosures to the ultimate debtor at the time it is determined to consummate the transaction as a secured loan rather than a lease." It is our opinion that your proposed alternative is acceptable under 49 CFR Part 580, so long as the bank transmits the disclosure to the transferee. The lessor, as transferor, would be responsible for furnishing the transferee with the statement. Should the bank fail to transmit the statement, the lessor could be held responsible for the bank's negligence. |
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ID: nht76-3.8OpenDATE: 08/30/76 FROM: AUTHOR UNAVAILABLE; Mark Schwimmer; NHTSA TO: Interpretations File TITLE: FMVSS INTERPRETATION TEXT: SUBJECT: TELEPHONE CALL FROM MR. DAVE HUNT, NADA On August 26, 1976, I spoke with Mr. Dave Hunt of the National Automobile Dealers Association (821-7030). He referred to a letter sent by General Motors Corporation to some of its dealers, concerning the relation between dealer installations of trailer hitches and Federal Motor Vehicle Safety Standard No. 301-75, Fuel System Integrity. Because neither of us had actually seen the letter, we discussed that relationship in general terms. I explained that the installation of a trailer hitch on a used vehcle would be subject to the "knowingly render inoperative" provision -- Section 108(a)(2)(A) -- of the National Traffic and Motor Vehicle Safety Act of 1966, as amended, and referred to Mr. Hunt to our May 18, 1976, letter on this subject to Mr. Larry Henneberger. I explained further that the most relevant portion of that statute concerning the installation of a trailer hitch on a vehicle before its first purchase in good faith for purposes other than resale would be Section 108(a)(1)(A). |
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ID: nht88-2.21OpenTYPE: INTERPRETATION-NHTSA DATE: MAY 7, 1988 FROM: WILLIAM K. BALDWIN TO: NHTSA TITLE: "THE BALDWIN REAR-VIEW MIRROR SAFETY SYSTEM" PARTLY COVERED BY U.S. PAT. #3,667,833 ATTACHMT: ATTACHED TO MEMO DATED 8-26-88, TO WILLIAM K. BALDWIN, FROM ERIKA Z. JONES, STD 111, VSA 108(A) (2)(A) TEXT: My rear-view mirror safety system offers the latest in technology and safety in performance of all types of automotive vehicles. These mirrors in conbination will absolutely and completely eliminate the hazardous blind spots on both sides of the vehicle , not just the right side which is presently being used by auto manufacturers. You do not have to turn your head or twist your body to check out traffic in the blind spot areas not visible in the conventional flat rear-view mirrors. It has always been my contention that convex (reduced image) mirrors should be used in conjunction with flat rear-view mirrors in order to obtain a safe and true rear-view vision. These conbination interior and exterior, (both sides) rear-view mirror s are most effective. The present reduced image only, right side only rear-view mirrors used by most auto manufacturers today are not sufficiently effective. Every motorist needs this rear-view mirror safety system. It increases visibility for safer d riving which in turn saves lives. It is my desire to submit my "BALDWIN REAR-VIEW MIRROR SAFETY SYSTEM" for your evaluation and hopefully your approval. Please respond as soon as possible to this proposal. ENCLOSURES Baldwin Rear View Mirror Safety System PATENT NO. 3,667,833 These products will absolutely and completely eliminate the hazardous blind spots on both sides of your vehicle. You do not have to turn your head or twist your body to check out traffic in the blind spot area not visible in the conventional flat rear v iew mirrors. VEHICLE IN BL/NL SPOT AREA FLAT REAR-VIEW MIRRORS FIELD OF VIEW EXTRA WIDE FULL-VIEW(Illegible Word) REAR-VIEW VISION MIRROR SAFETY SYSTEM" OF VIEW |
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ID: nht92-9.20OpenDATE: February 7, 1992 FROM: Charles Danis, P.Eng. -- Les Entreprises Track Test Inc. TO: Paul Jackson Rice -- Chief Counsel, NHTSA TITLE: Subject: Interpretation of FMVSS 121 - S5.3.3 (as per our phone call with your Mr. Marvin Shaw, on February 6th 1992) ATTACHMT: Attached to letter dated 4/3/92 from Paul J. Rice to Charles Danis (A39; Std. 121) TEXT: We recently performed a compliance FMVSS 121 test on an articulated bus made by MCI Greyhound Canada. For the middle axle of this articulated bus, MCI is using different air pressures than those specified in paragraph S5.3.3. of FMVSS 121 (for reasons of safety). Based on the attached interpretation dated July 23rd 1976 from your Mr. Frank A. Berndt, MCI is using 40 psi as initial service reservoir system air pressure and 28 psi as brake. chamber pressure (at .45 sec. max.). In the case of release, MCI is using 40 psi. We would appreciate very much if you could confirm by return that this attached interpretation is still valid. |
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ID: nht87-1.17OpenTYPE: INTERPRETATION-NHTSA DATE: 07/13/87 FROM: AUTHOR UNAVAILABLE; Erika Z. Jones; NHTSA TO: Dr. Ernst; Hella KG Hueck & Co. TITLE: FMVSS INTERPRETATION TEXT: Dr. Ernst Hella KG Hueck & Co Postfach 28 40 4780 Lippstadt GERMANY Dear Dr. Ernst: This is in reply to your letter of February 5, 1987, to Richard Van Iderstine of this agency's Office of Vehicle Safety Standards. You have asked for an interpretation of Motor Vehicle Safety Standard No. 108 with respect to a new headlamp manufactured by Hella that BMW has installed on a new car which it introduced in the United States around April 1, 1987. The headlamp is of the replaceable bulb type, and as you describe it consists of two additional parts: "the housing, to which the cover lens is bonded by means of a two "component adhesive", and 'the optical module, consisting of the reflector and the convex lens, joined by the lens carrier...." In your words, "The two parts are held together by three screws", and you believe that "the two parts, firmly screwed together, are as effectively joined as would be the case if bonded". Paragraph S3 of Standard No. 108 defines a "replaceable bulb headlamp" in pertinent part as "a headlamp comprising a bonded lens and reflector assembly. . . ." In the Hella design, the lens and reflector assembly are not bonded, and thus the headlamp is not a "replaceable bulb headlamp" that is permissible for use on motor vehicles sold and used in the Unite States. The intent of the definition is to ensure that the headlamp lens and reflector are an integral replaceable unit, since that is the only means to assure a mechanically aimable replaceable bulb headlamp which is capable of using any replacement standardized replaceable light source and meets the necessary photometric performance. The foundation of mechanical aimability is that the beam and aiming pads are manufactured to have a specific relationship. If this relationship is altered by replacement of the lens only, or of the reflector only, there is a high likelihood that the lamp may not meet minimum performance requirements when aimed mechanically. |
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ID: nht95-6.55OpenTYPE: INTERPRETATION-NHTSA DATE: September 25, 1995 FROM: John Womack -- Acting Chief Counsel, NHTSA TO: Dennis G. Moore -- President, Sierra Products, Inc. TITLE: NONE ATTACHMT: ATTACHED TO 7/31/95 LETTER FROM DENNIS G. MOORE TO NHTSA CHIEF COUNCIL (OCC 11123); ALSO ATTACHED TO LETTER DATED 3/4/77 FROM FRANK BERNDT TO DENNIS G. MOORE TEXT: Dear Mr. Moore: This responds to your letter of July 31, 1995, on the subject of "optical combination" as that term is used in Motor Vehicle Safety Standard No. 108. You enclosed a copy of a letter sent to you from this Office on March 4, 1977, and refer to a "Rider" in "a proposed change [around 1990] that had no relevance to this subject, whereas the Rulemakers added the expression, 'NOT TO SHARE THE SAME HOUSING.'" You ask how "[using] the Scientific Argument and discussions I submitted back in 1975, 1976, and 1977, and the Re-Interpretation letter sent me, how can NHTSA support the SAME HOUSING definition they currently support." You are talking of events of 18 to 20 years ago that are no longer relevant today. The definition that NHTSA supports contains no reference to lamp housings. Standard No. 108 was amended four years ago, in 1991, to clarify that the term "optical combination" is to be interpreted as defined by SAE Information Report J387 Terminology - Motor Vehicle Lighting NOV87. Under the SAE definition, optical combination results when a lamp "has two or more separate light sources, or a single light source that operates in different ways (e.g., a two-filament bulb)", and when "its optically functional lens area is wholly or partially common to two or more lamp functions." It is immaterial to this definition whether the light sources are in the same or different housings. I enclose a copy of a rulemaking proposal and final rules dealing with this issue that were published on November 6 and 8, 1990, and June 7 and November 7, 1991. If you have further questions, you may refer them to Taylor Vinson of this Office by FAX (202-366-3820).
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ID: nht79-3.28OpenDATE: 04/27/79 FROM: AUTHOR UNAVAILABLE; F. Berndt; NHTSA TO: B. F. Goodrich Company TITLE: FMVSS INTERPRETATION TEXT: This responds to a January 15, 1979, request from Mr. A. J. Burt to permit adjustment of foundation brakes during the burnish procedures in S6.1.8 and S6.2.6 of Standard No. 121, Air Brake Systems, for any reason. At present, such adjustments can only be made to control brake temperature, as stated in our January 24, 1979, letter to Mr. Burt. The National Highway Traffic Safety Administration is unaware of a reason other than control of brake temperature which would justify adjustments during burnish. Accordingly, we decline to grant your request. The NHTSA would, of course, be willing to consider any data or other information you have which would indicate that the present interpretation of burnish procedures may be too narrow in this respect. SINCERELY, BFGoodrich Engineered Systems Division January 15, 1979 Department of Transportation 400 7th Street S.W. Attention: Tad Herlihy Dear Mr. Herlihy: This letter is to confirm our telephone conversation of January 10th regarding our November 8, 1978 letter from Mr. D. L. Haines to the Chief Cousel, requesting clarification of certain sections of Paragraphs S5.3, S5.4, S6.1.8, and S6.2.6 of FMVSS-121 as pertain to brake adjustment during brake burnish. On November 28, 1978, in answer to my telephone request for a quick response, Mr. Haines was sent a copy of FR Doc. 74-26461 filed 11/7/74. That document states that "brake adjustment can be made during the burnish to control brake temperature". As discussed in our January 10th conversation, BFGoodrich is asking that an additional written response be made to our letter which requests, for the reasons stated in that letter, concurrence with the more general conclusion "that adjustment during burnish prior to road or dynamometer testing is acceptable". Please address the response to Mr. D. L. Haines. A. J. Burt Manager Highway Products Support Engineering CC: D. L. HAINES |
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ID: nht72-1.24OpenDATE: 09/28/72 FROM: AUTHOR UNAVAILABLE; R. B. Dyson; NHTSA TO: Associate Mgt. Services, Inc. TITLE: FMVSS INTERPRETATION TEXT: This is in response to your letter of August 22, 1972, concerning the recently issued amendment to Standard No. 109 (37 F.R. 16604, August 7, 1972) prohibiting the sale of "reclassified" tires. You indicate that you agree with the amendment that such tires should be allowed to be sold as scrap, but suggest that it be only after they are (Illegible Word) completely inoperable for any vehicular use. The amendment to the standard prohibits, in effect, the distribution by a manufacturer of any tire does not conform to the standard, unless it is impossible that the tire (Illegible Word) be used or be repaired for use as motor vehicle equipment (see paragraph S2, Application, of the enclosed copy). Whether cutting the bead on a tire meets this requirement is for each individual manufacturer to determine. We have received some reports that it is possible to repair the bead of a tire so that the tire can still be used on a motor vehicle. If this is the case, cutting a tire's bead may not be sufficient to allow the tire to be sold as scrap under the National Traffic and Motor Vehicle Safety Act. The amendment, then, does achieve the result you suggested in that it does require a noncomplying tire to be "completely inoperable for any vehicular use" before it can be sold as scrap. We appreciate your continued efforts for motor vehicle safety. Enclosure |
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ID: 3150oOpen Mr. Mark Jansen Dear Mr. Jansen: This is in reply to your letter of September 17, 1988, to Taylor Vinson of this Office. You would like to have parking lamp and tail lamp lenses "remanufactured" for use on l947-66 Chevrolet and GMC pickup trucks, and have requested our views. We assume that you wish to have lenses manufactured to replace original equipment lenses on the trucks produced in the years indicated. Essentially, your operation appears unaffected by the requirements of this Department. The Federal motor vehicle lighting standard applies only to lenses intended to replace original lenses on vehicles manufactured on and after January l, l972, and would not cover lenses for use on l947-66 trucks. However, if the lenses you intend to manufacture are interchangeable with those on vehicles manufactured on and after January l, l972, you may have an obligation to ensure that they meet Federal requirements. If this is the case, we would be pleased to advise you further. Notwithstanding the foregoing, all replacement lenses are equipment that is subject to Federal notification and remedy provisions if they incorporate a defect that relates to motor vehicle safety. In your case, this likelihood may be remote as the item concerned is a simple one, but attention should be paid to quality control. Sincerely,
Erika Z. Jones Chief Counsel ref:l08 d:ll/3/88 |
1970 |
ID: nht90-4.77OpenTYPE: Interpretation-NHTSA DATE: December 7, 1990 FROM: Paul Jackson Rice -- Chief Counsel, NHTSA; Signature by S.P.W. TO: Takahiro Maeda -- Assistant to the Vice President, Engineering Division, Yamaha Motor Corporation, U.S.A. TITLE: None ATTACHMT: Attached to letter dated 9-28-90 to Office of Chief Counsel, NHTSA from Takahiro Maeda (OCC 5275) TEXT: This is in reply to your letter of September 28, 1990, requesting an interpretation of Motor Vehicle Safety Standard No. 108. Table IV of the standard establishes a minimum "edge to edge separation distance" between turn signal lamps and tail or stop lamps installed on motorcycles. You have asked whether the edge in question is the outer edge of the lamp assembly itself, or th e edge of the reflector in the lamp. The minimum edge to edge separation distance is measured from the edge of the illuminated surface of one lamp to another, that is to say, from the edge of the effective projected luminous area of one lens to the edge of the effective projected luminous a rea of the other. It is unclear from the drawing you enclosed of the "tail/brake lamp" whether the edge of its effective projected luminous area of the lens is at the edge of the reflector, or at the edge of the lamp (as appears to be the case with the "turn signal"). If the former, the distance is measured between the edge of the tail/stop lamp reflector to the edge of the turn signal lamp assembly as you have initially indicated. |
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.