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: nht75-2.31OpenDATE: 05/20/75 FROM: AUTHOR UNAVAILABLE; R. B. Dyson; NHTSA TO: Toyo Kogyo co., Ltd. TITLE: FMVSS INTERPRETATION TEXT: In reply to your letter of April 22, 1975, the "wheel nuts" covered by Motor Vehicle Safety Standard No. 211 are large, center-mounted hub nuts, one to a wheel, that lock the tire to the axle. They are not the individual nuts, often six to a wheel, that perform the same function, and which are generally covered by a wheel disc or hub cap. Your hub nuts and hub bolts therefore need not be marked with a manufacturer's identification code. YOURS TRULY, April 22, 1975 James C. Schultz Chief Counsel National Highway Traffic Safety Administration In the Docket No. 73-14; Notice 3 issued in the Federal Register dated on March 19, 1975, S 571.211 S 3.2. says, "Each wheel nut, wheel disc, and hubcap shall be permanently and legibly marked or labeled with the manufacturer's identification code---" As shown in the sketch below, we use two ways to put the wheels on the vehicle, that is either (a) by screwing hub bolts only, or by screwing hub nuts into hub bolts inserted in the dram or disc with the pressure. We are now wondering if these hub nut and hub bolt will be included in above requirement. We would appreciate your view on this issue. Thank you. H. (SPEEDY) Hirai Technical Representative Toyo Kogyo Co., Ltd. (MAZDA) Representative Office (Graphics omitted) |
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ID: nht74-5.42OpenDATE: 03/20/74 FROM: AUTHOR UNAVAILABLE; R. B. Dyson; NHTSA TO: Western Auto Associate Store TITLE: FMVSS INTERPRETATION TEXT: This responds to your request for information on Standard 119, New pneumatic tires for vehicles other than passenger cars, and on a "Petition #2" concerning exemption of "Mopeds" from the motorcycle regulatory category. Standard 119 applies to tires, not vehicles, and therefore it regulates only the manufacturer of the tire, not a retailer of vehicles like yourself. The "Petition #2" to which you refer was filed by Mr. Robert Smith of Ohio Bikes, 631 Broad Street, Columbus, Ohio 43215, asking for a redefinition of "motorcycle" to exclude Moped-type vehicles, and a change in the lighting standard to exclude Moped-type vehicles from the present motorcycle requirements. Yours truly, WESTERN AUTO ASSOCIATE STORE RICHARD B. DYSON A'SST. CHIEF COUNSEL DEPT. OF TRANSPORTATION I thank you for your responsive letter Feb 4, 1974 concerning my inquiry on Status of Solex reports. In your letter you(Illegible Word) to a new standard affecting tires on mopels. Standard #119 effective March 1, 1975. Could you please furnish me with the specific requirements of this standard. Also(Illegible Words) of a new Petition, referred to as Petition #2 which is currently before the D.O.T. asking that some of these requirements on mopels be(Illegible Word) to the extent that they not be classified with motorcycles but more in the cycle classification. Could you please furnished us with more detailed information regarding this Petition. THANK YOU. |
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ID: nht75-3.39OpenDATE: 09/10/75 FROM: AUTHOR UNAVAILABLE; F. Berndt; NHTSA TO: Duo-matic Importers LTD. TITLE: FMVSS INTERPRETATION TEXT: This responds to Duo-matic's August 19, 1975, question whether Standard No. 121, Air Brake Systems, applies to an air brake coupler device that connects air brake hoses from a truck to the trailer it tows. The answer to your question is no. Paragraph S3 (Applicability) of Standard No. 121 states that the standard applies to trucks, buses, and trailers equipped with air brake systems (with some stated exceptions). The standard therefore applies only to vehicles, and does not apply to motor vehicle equipment such as the Duo-matic coupler device. SINCERELY, August 19, 1975 Richard B. Dyson Assistant Chief Council Office of the Chief Council Federal Highway Administration Refer to: A: Your letter N-40-30(MIS) dated 6-3-75 B: Motor Vehicle Safety Standard #121 as amended S5.3.3 Brake Actuation Time. With attached amendments of 11-12-74, 1-7-75, 1-17-75, 3-4-75, 3-21-75, 3-26-75, 5-15-75, and 6-11-75. C: Duo-Matic Double Quick Release Coupling for Semi-Trailers (452-803) D: Duo-Matic Double Quick Release Coupling for Towing Trailers (452 802) The question is if Reference B above applies to our Wabco Westinghouse Duo-Matic coupler, which replaces the Glad Hand coupling now in use. Your interpretation would be very much appreciated. We have enclosed two copies each of references C & D. H. Melvin Strand, President |
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ID: nht67-1.22OpenDATE: 11/27/67 FROM: AUTHOR UNAVAILABLE; Andrew K. Ness; NHTSA TO: Blue Bird Body Company TITLE: FMVSS INTERPRETATION TEXT: This is in response to your letter of November 10, 1967, in which you requested a clarification of the use of the term "combined optically" as used in Motor Vehicle Safety Standard No. 188, Sections S8.3(c) and S3.4.4.3. S3.3(c) Lamp Combinations and Equipment Combinations. Two or more lamps, reflective devices, and items of associated equipment may be combined if the requirements for each lamp, reflective device, and item of associated equipment are Met, except that -- (c) No clearance lamp may be combined optically with any taillamp or identification lamp. This means that no clearance lamp may be combined to use a lense that is common to any other lamp such as a taillamp or identification lamp. The clearance lamp shall have a unique lense. S3.4.4.3 Stoplamps that are combined optically with turn signal lamps need not be operable when the combination is in use as a turn signal or as a vehicular hazard warning signal. This means that stoplamps that have a lense that is common with the turn signal lamps do not have to be operable when the combined stoplamp and turn signal lamp is used primarily as a turn signal or as a hazard warning signal. Stoplamps need not be operable when the combined stoplamp and turn signal lamp unit is used as a hazard warning or turn signal indicator. We trust these comments will be of assistance in clarifying your problems. |
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ID: nht68-1.2OpenDATE: 01/01/68 EST. FROM: R. M. O'Mahoney; NHTSA TO: Ontario Department of Transport TITLE: FMVSS INTERPRETATION TEXT: This is in confirmation of our telephone conversation of August 26, 1968, and in reply to your letter of July 22, 1968, in which you inquire as to the meaning of "manufacturer" in the Tire Standard, No. 109, particularly in light of the practice of concealing the identity of the real maker of the tires. The term "manufacturer" employed in the labeling requirements section of that standard, by the rule set forth in 23 C.F.R. @@255.3, is used in the meaning defined in section 102 of the National Traffic and Motor Vehicle Safety Act of 1966, 15 U.S.C.@@1391: "Manufacturer means any person engaged in the manufacturing or assembling of motor vehicles or motor vehicle equipment, including any person importing motor vehicles or motor vehicle equipment for resale." The clear implication of this definition is that we are to be concerned with the company that is the actual maker of the tires in question, not retail outlets, suppliers who are not manufacturers, or other parties who may misleadingly appear to be the manufacturer. We are not aware of any situation where the ownership or control of the tire manufacturing operation is so fragmented as to leave the relevant identity of the manufacturer unclear, within the meaning of the above. If such a case is brought to our attention, we will deal with it on its own facts. We are happy to be of assistance. |
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ID: nht68-1.24OpenDATE: 05/09/68 FROM: SIGNATURE UNAVAILABLE; NHTSA TO: Counihan, Casey and Loomis TITLE: FMVSS INTERPRETATION TEXT: Thank you for your letter of March 4, 1968, to Mr. Edwin L. Slagle, concerning Federal Motor Vehicle Safety Standard No. 205. Standard No. 205 requires that glazing materials manufactured for use in passenger cars, multipurpose passenger cars, multipurpose passenger vehicles, trucks, buses, and motorcycles for sale in the United States on or after January 1, 1968, meet the requirements of ASA standard 226.1966. In addition, passenger cars, multipurpose passenger vehicles, trucks, buses, and motorcycles manufactured on or after January 1, 1968, for sale in the United States, must contain glazing materials that meet the requirements of ASA Standard 226.1-1966. The following information is offered in answer to your qeustions: Q. "We would appreciate your advice as to whether under Section (sic) 205, our members may install windshields manufactured prior to January 1, 1968, and containing a plastic interlayer of 0.015" subsequent to January 1, 1968?" A. Yes, preformed or presized windshields manufactured prior to January 1, 1968, of 0.015 plastic interlayer may be used as replacement glass in used vehicles after January 1, 1968. Q. "We would also appreciate your advice as to whether the fact that a glass dealer cuts a windshield to size from material manufactured prior to January 1, 1968, would alter your answer to our first question." A. A dealer who cuts a windshield to size is considered a manufacturer, hence after January 1, 1968, 0.015 plastic interlayer [Page 2 Is Missing.] |
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ID: nht68-2.10OpenDATE: 06/04/68 FROM: AUTHOR UNAVAILABLE; Robert M. O'Mahoney; NHTSA TO: Canadian Embassy TITLE: FMVSS INTERPRETATION TEXT: This is in responce to your letters of April 15 and February 15 to Mr. B. A. Boaz of the Office of Public Affairs, Federal Highway Administration. With reference to a Canadian manufacturer of motor buses you have asked "What safety regulations currently apply to importation of motor buses." Federal Motor Vehicle Safety Standards Nos. 102, 107, 205, and 209 currently apply to all motor buses; in addition, Standard No. 108 applies to motor buses 50 inches or more in overall width. I enclose a copy of the Standards for your guidance, together with a copy of the regulations governing importation of these vehicles. You have also asked advice as to placing of lights required, vehicle braking requirements, and propane tank installation for "tent camper trailers" and "truck campers" manufactured by Specialites Capri limited of Montreal. Standard No. 108 applies to all trailers 80 or more inches in overall width, and specifies the lighting requirements for these vehicles. Thus far it is the only standard applicable to trailers. Therte are no Federal braking or propane talk installation requirements for these vehicles. The truck camper manufactured by Capri is considered motor vehicle equipment and must conform to the glazing material requirements of Standard No. 205. I enclose a copy of a recent Notice of Ruling Regarding Campers which will be of assistance to Capri. If there are further questions we shall be glad to answer them, and I am sorry for the delay in responding to you. |
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ID: nht68-2.5OpenDATE: 05/14/68 FROM: AUTHOR UNAVAILABLE; David A. Fay; NHTSA TO: Northern California Ready Mixed Concrete and Materials Association TITLE: FMVSS INTERPRETATION TEXT: Thank you for your letter of April 8, 1968, to Mr. George Nield, concerning the location requirements for clearance lamps as specified by Federal Motor Vehicle Safety Standard No. 108. Enclosed is a copy of the Federal Motor Vehicle Safety Standards (with amendments and interpretations through February 15, 1968). Standard No. 108 appears on page 39 of this publication. The location requirements for clearance lamps are included in Table II (page 50), of the standard. Since the requirements specify locations as near as practicable to the upper left and right extreme edges of the vehicle, the exact locations will vary, depending upon the design and utilization of the vehicle on which the lamps are mounted. When the rear identification lamps are mounted at the extreme height of the vehicle, rear clearance lamps may be mounted at optional heights. I would also point out that Standard No. 108 is applicable to new vehicles manufactured for sale on or after the effective date of the standard. With respect to the requirements of Standard No. 108, I must point out that this Bureau does not issue approvals on items of lighting equipment or on vehicle designs incorporating this equipment. Therefore, the above comments are for your information only and in no way relieve the vehicle manufacturer from his responsibility for certifying that the assembled vehicle meets the requirements of the standard. Thank you for writing. |
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ID: nht68-4.17OpenDATE: 09/17/68 FROM: AUTHOR UNAVAILABLE; William Haddon, Jr.; NHTSA TO: Chrysler Corporation TITLE: FMVSS INTERPRETATION TEXT: Thank you for your letter of September 11, 1968, to Mr. J.E. Leysath of this Bureau, concerning the Chrysler Super Lite which you intend to offer as an optional supplemental light on some of the Chrysler 1969 car lines. You are correct in your understanding that a supplemental light of this type is not required by Federal Motor Vehicle Safety Standard No. 108. Standard No. 108 does, however, specify, in Paragraph S3.1.2, that no additional lamp, reflective device, or associated equipmont shall be installed if it impairs the effectiveness of the required equipment. On the basis of our review of your technical literature on the Super Lite and our observation of limited field demonstrations of the light, it does not appear that the Super Lite will impair the effectiveness of the lighting equipment required by Standard No. 108. It should be noted, however, that, while the incorporation of this lamp in your 1969 automobiles would not be precluded by the Federal Standard, the various States may interpose restrictions as to this lamp. With respect to the requirements of Standard No. 108, I must point out that this Bureau does not issue approvals on items of lighting equipment or on vehicle designs incorporating this equipment. Therefore, the above comments are for your information only and in no way relieve the vehicle manufacturer from his responsibility for certifying that the assembled vehicle meets the requirements of the standard. |
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ID: nht68-4.9OpenDATE: 09/03/68 FROM: AUTHOR UNAVAILABLE; Robert M. O'Mahoney; NHTSA TO: Department of California Highway Patrol TITLE: FMVSS INTERPRETATION TEXT: This is in reply to your letter of August 19, 1968. You state that you do not find any provision which would permit temporary mounting of lighting devices on mobile homes and ask that we inform you what provision in Public Law 89-563 or the Federal motor vehicle safety standards permits installation of temporary devices. There is no provision in P.L. 89-563 or the standards which either permits or prohibits the temporary mounting of devices. The National Highway Safety Bureau has taken the position that, insofar as mobile homes are concerned, temporary lighting devices may be used if they meet the requirements of Standard No. 108. With respect to your request for a copy of Docket No. 26, I enclosed a copy of the notice of request for comments recently issued and published in the Federal Register. This docket was opened several months ago and contains several hundred pages of documents. The docket is scheduled to remain open, for the receipt of additional comments, until September 10, 1968. Our rules require us to charge 50 cents per page, payable in advance for copies of docket material. should you want a copy of the complete docket, please let us know and we will advise you, after September 10, of the fee for this service. Thank you for your continuing interest in motor vehicle safety. |
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.