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: nht72-3.1OpenDATE: 01/25/72 FROM: AUTHOR UNAVAILABLE; E. T. Driver; NHTSA TO: North Carolina Tire Dealers Retreaders Association, Inc. TITLE: FMVSS INTERPRETATION TEXT: Thank you for sending a copy of your December 1971 issue "Tarheel Tire Topics". In a note attached to these topics you asked Dr. E. H. Wallace to clarify whether a tubeless tire casing can be changed to a tube-type retread by identifying it as such during the process. There is no prohibition of this practice mentioned in Standard No. 117 relating to retreaded tires. (Illegible Words) the rule is clear concerning the necessity for maintaining the highest quality in selection of materials and processings during the retreaded process. We would be interested in an explanation of the circumstances where it appears necessary to change a tubeless casing to a tubed tire. The circumstances which we visualize leading to this change seem to us to lead to rejection of the casing for any retread purposes. We also would like to point out that, although not strictly prohibited, the manufacturer who changes a tubeless casing to a tubed tire is liable for penalties if the resulting tire will not perform on compliance tests. |
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ID: nht72-3.10OpenDATE: 09/07/72 FROM: AUTHOR UNAVAILABLE; Robert L. Carter; NHTSA TO: Kennedy, Holland, DeLacy and Svoboda, Attorneys at Law TITLE: FMVSS INTERPRETATION TEXT: Your letter dated July 27, 1972, to the Department of Commerce, regarding information pertaining to the National Traffic and Motor Vehicle Safety Act of 1966, initial standards, was referred to this office for reply. The National Traffic and Motor Vehicle Safety Act of 1966, in establishing the legislative basin for the Federal Motor Vehicle Safety Standards, required that the initial standards, to the maximum extent possible, be based on existing safety standards. An Advance Notice of Proposed Rule Making, soliciting suggestions, opinions, and proposals for consideration in promulgating the initial standards, was published in the Federal Register on October 8, 1966. Paragraph S3.3(d) of the initial Motor Vehicle Safety Standard No. 201 was based on Paragraph S3.2.5 of Federal Standard No. 515/3a, which was published in the Federal Register on July 15, 1966, (31 F.R. 9628), after consideration of the comments received in response to the Advance Notice. I have enclosed a copy of Standard No. 515/3a. Thank you for your letter. Your interest in automotive safety is appreciated. |
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ID: nht72-3.11OpenDATE: 04/03/72 FROM: AUTHOR UNAVAILABLE; Richard B. Dyson; NHTSA TO: Pike Paint & Glass Company, Inc. TITLE: FMVSS INTERPRETATION TEXT: This is in reply to your letter of March 15, 1972, requesting information on requirements for replacing broken glass in campers and trailers. Federal regulations (Motor Vehicle Safety Standard No. 205, "Glazing Materials" (49 CFR 571.205, formerly 571.21)) require glazing materials for use in motor vehicles and motor vehicle equipment such as campers to meet the requirements of the American National Standards Institute Test Z26.1-1966 (July 15, 1966), and other requirements enumerated in the standard. In addition, manufacturers of such materials are required to certify, pursuant to section 114 of the National Traffic and Motor Vehicle Safety Act (15 U.S.C. 1403) that the materials comply with the standard. This requirement applies to both prime manufacturers (those who either fabricate, temper, or laminate the material) and those who cut material from larger sheets. The standard does not apply to trailers. With reference to campers, the standard requires that forward facing windows be constructed of glazing materials meeting tests for AS1, AS2, AS3, AS4, or AS5 glazing materials, which are described in ANS Test Z26.1-1966. Other camper windows may be of any glazing material that meets the requirements of the standard (AS1 through AS11). All of the materials which can be used under the standard are readily available. A notice of proposed rulemaking issued January 9, 1971, would allow additional materials to be used in campers, and the preparation of a final regulation regarding this matter is currently in process. The final regulation will, when issued, be published in the Federal Register. A copy of Standard No. 205 is enclosed. The American National Standards Test Z26.1-1966, which is incorporated into the standard must, however, be obtained directly from the American National Standards Institute. Their address is 1430 Broadway, New York, New York 10018. If you have further questions, please write. |
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ID: nht72-3.12OpenDATE: 06/09/72 FROM: ELWOOD DRIVER FOR ROBERT L. CARTER -- NHTSA TO: S.P.A. Carrozzeria Pininfarina TITLE: FMVSS INTERPRETATION TEXT: Thank you for your letter of May 25, 1972, inquiring about the applicability of Federal Motor Vehicle Safety Standard (FMVSS) No. 205, and FMVSS No. 302, to the rear windows of convertible cars. In FMVSS No. 302, the convertible top is not intended to refer to the rear window, but has reference only to the overhead material. Flammability of the transparent glazing material is regulated by FMVSS No. 205. |
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ID: nht72-3.13OpenDATE: 04/03/72 FROM: Robert L. Carter; NHTSA TO: Fabrica Pisana S.P.A. TITLE: FMVSS INTERPRETATION TEXT: Thank you for your letter of March 10, 1972, concerning marking of your glazing materials intended for the American market. The marking you propose to use satisfied the requirements of Standard No. 205, Glazing Materials. |
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ID: nht72-3.14OpenDATE: 07/05/72 FROM: AUTHOR UNAVAILABLE; Richard B. Dyson; NHTSA TO: Mr. Robert T. Sanders TITLE: FMVSS INTERPRETATION TEXT: This is in reply to your letter of June 1, 1972, requesting an interpretation as to the application of Federal Motor Vehicle Safety Standard No. 205. "Glazing Materials," to certain recreational vehicles and equipment, pictures of which you enclosed. These components consist of slide-in and chassis-mount campers, trailers, and motor homes. In a recently issued amendment to Standard No. 205, the NHTSA has clarified the application of the standard to campers. As amended, the standard applies to campers, both slide-in and chassis-mount, that are designed to transport occupants while in motion. Accordingly, the pick-up cap which you illustrate appears to be except from the standard. In addition, Standard No. 205 does not apply to trailers, and would not apply to the fifth-wheel unit illustrated in the drawing forwarded to us. With reference to the chassis-mount and slide-in campers, any window except forward facing windows, which include both front-facing windows and behind-the-cab windows, may be manufacturered of any glazing material (AS 1 through AS 11) specified in ARS Z26.1-1966, and two additional materials (Items 32 and 33), the requirements for which are specified in the recent amendment. With reference to forward-facing camper windows, all of the above materials may be used, except for AS 6 and AS 7 glazing materials, as specified in ANS Z26.1-1966 and item 13 glazing specified in the new amendment. With respect to motor homes that are not campers, these vehicles are multipurpose passenger vehicles and must meet the glazing requirements for trucks. Accordingly, the windshield must be manufactured of either AS 1 or AS 10 glazing materials, side windows to the (immediate right or left of the driver must be either AS 1, AS 2, AS 10, or AS 11 materials, and other side windows must be either AS 1, AS 2, AS 3, AS 4, AS 5, AS 8, AS 9, AS 10, or AS 11 glazing materials. We would consider the overhead window in the motor home you (illustrate to be an "opening in the roof," and any of the materials allowed in side windows, or the materials allowed to be used by the recent amendment, may be (Illegible Word) in this location. |
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ID: nht72-3.15OpenDATE: 06/12/72 FROM: AUTHOR UNAVAILABLE; Richard B. Dyson; NHTSA TO: Silver-Top Manufacturing Co., Inc. TITLE: FMVSS INTERPRETATION TEXT: This is in reply to your letter of April 26, 1972, inquiring whether you are required to use "laminated safety glass" in the forward-facing window of a pickup cap. You indicate that this window is below the roof line of the cab of the pickup, immediately behind its rear window. Under Federal Motor Vehicle Safety Standard No. 205, "Glaring Materials", (49 CFR 571.205, copy enclosed) windows in campers, pickup caps, pickup canopies, and pickup covers must be manufactured of safety glazing material specified in the standard, Forward-facing windows such as the one you describe must be manufactured of either AS1, AS2, AS3, AS4, or AS5 glazing materials, as those materials are described in the American National Standards Institute Test E26.1-1966. Materials other than "laminated safety glazing" may be used to meet each of these "AS" categories, and we refer you to ANS Test 226.1 for specific requirements. |
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ID: nht72-3.16OpenDATE: 05/08/72 FROM: AUTHOR UNAVAILABLE; Richard B. Dyson; NHTSA TO: Temptation Mfg. Co. TITLE: FMVSS INTERPRETATION TEXT: This is in response to your undated letter, which we received on March 22, 1972, in which you ask what NHTSA requirements are applicable to a truck cover you manufacture, enclosing a picture. The picture appears to show a cover designed for installation over the back of a pickup truck. If this unit is not designed to carry persons when the truck is in motion, there are no requirements applicable to it. If, however, it is designed to transport persons, the glazing materials (glass and plastics) used in it must conform to Motor Vehicle Safety Standard No. 205, "Glazing Materials," (copy enclosed). In addition, the unit must also be certified as conforming to the standard in accordance with section 114 of the National Traffic and Motor Vehicle Safety Act and the enclosed NHTSA notice of November 4, 1967. The ASA Test 226.1-1966 that is incorporated into Standard No. 206 can be obtained from the American National Standards Institute, 1430 Broadway, New York, New York 10018. |
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ID: nht72-3.17OpenDATE: 02/16/72 FROM: AUTHOR UNAVAILABLE; Richard B. Dyson; NHTSA TO: Compact Corporation TITLE: FMVSS INTERPRETATION TEXT: This is in reply to your letter of December 29, 1971, concerning the use of glazing materials in the Kangaroo Camper which your company manufactures. You ask whether Motor Vehicle Safety Standard No. 205, "Glazing Materials" (49 CFR @ 571-205) applies to this item. Because it is impossible for a person to ride in the Kangaroo camper while the vehicle is in motion, we would not consider this item to be a "camper" within the meaning of Standard No. 205, and the standard does not apply to this product. |
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ID: nht72-3.18OpenDATE: 05/31/72 FROM: AUTHOR UNAVAILABLE; Richard B. Dyson; NHTSA TO: GO Industries TITLE: FMVSS INTERPRETATION TEXT: This is in reply to your letter of April 26, 1972, requesting an opinion as to whether "Abcite," a product of the Dupont Company, may be used in campers and "mini-mobile homes." Whether a particular glazing material may be used in motor vehicles or campers depends upon whether the material meets the requirements of Motor Vehicle Safety Standard No. 205, "Glazing Materials" (49 CFR 571.205), which incorporates, as you indicate, the American National Standards Institute Standard Z26.1-1966. That standard also specifies the locations in motor vehicles where specific materials may be used. Standard No. 205 does not apply to trailers. While we are not familiar with the phrase "mini-mobile home," we consider mobile homes to be trailers, and the standard does not apply to them. With respect to campers, Standard No. 205 allows the use of any material meeting the requirements of Z26 in any location except for forward-facing windows. Forward-facing camper windows may not be manufactured of item 6 and item 7 material (AS6, AS7), but may be manufactured of any of the other materials (AS1-AS5, AS8-AS11) that meets the requirements of Z26. Whether Abcite conforms to the requirements for glazing allowed to be used in campers is a determination that should be made in the first instance by its manufacturer, Dupont. If the manufacturer determines that such use is within the requirements of Standard No. 205, he is required by section 114 of the National Traffic and Motor Vehicle Safety Act to certify that the material conforms to the requirements of the standard. He is also required by the marking requirements in Section 6 of Z26.1-1966 to indicate on the material its AS designation. Any material that is so certified can be used in the camper locations listed on the standard as appropriate for that designated type. |
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.