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: nht72-2.29OpenDATE: 06/12/72 FROM: AUTHOR UNAVAILABLE; C. A. Baker for E. T. Driver; NHTSA TO: Harker Enerprises, Inc. TITLE: FMVSS INTERPRETATION TEXT: This responds to your letter of May 22, 1972, to the Director, National Highway Traffic Safety Administration, concerning your patented Anti-Clare lenses for automotive headlights. Federal Motor Vehicle Safety Standard No. 108 does prohibit the installation of devices in front of the headlamp lens, and also allows only white light from the headlights (Illegible Word) you have correctly concluded. There is no expectation of any future significant change in this area of Standard No. 108 requirements. These requirements of Standard No. 108 are applicable to original equipment furnished on new vehicles; therefore, the allowance of sale of your Anti-Glare lenses in the aftermarket is under the jurisdiction of the Individual States. |
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ID: nht71-2.17OpenDATE: 03/05/71 FROM: AUTHOR UNAVAILABLE; Lawrence R. Schneider; NHTSA TO: Yarbrough Manufacturing Company Inc. TITLE: FMVSR INTERPRETATION TEXT: This is in reply to your letter of January 21, 1971 concerning tire Identification and Record keeping regulations. Enclosed for your information is a copy of the Tire Identification and Record Keeping Regulation (49 CFR 574). The regulation does not provide for exemptions or waivers, however, you will note that under @ 574.10 of the regulation vehicle manufacturers are required to keep records of tires on or in the vehicle when shipped to the dealer. Under the conditions you describe in your letter @ 574.9(b) appears to be the relevant section and requires that the vehicle dealer record the name, address, etc. of the purchaser and forward this information to the tire manufacturer. I hope this letter is responsive to the question you raise. Enclosure |
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ID: nht73-4.19OpenDATE: 05/09/73 FROM: AUTHOR UNAVAILABLE; Richard B. Dyson; NHTSA TO: Southern California Edison Company TITLE: FMVSR INTERPRETATION TEXT: This is in response to your letter of April 13, 1973, in which you ask whether the installation of a truck body or derrick on a new chassis-cab by your company for its own use makes it a final-stage manufacturer subject to the identification and certification provisions implementing the Highway Traffic and Motor Vehicle Safety Act, Public Law 89-563. The answer to your question is yes. The completion of a motor vehicle by a manufacturer for its own use does not relieve it of responsibility for certification. As a final-stage manufacturer, you are required to submit the information specified in 49 CFR Part 566, Manufacturer Identification. I am enclosing a copy of Part 566 for your information. No specific format is required, and a letter report will suffice. ENC. |
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ID: 1983-1.50OpenTYPE: INTERPRETATION-NHTSA DATE: 05/04/83 FROM: AUTHOR UNAVAILABLE; F. Berndt; NHTSA TO: Boschung Company, Inc. TITLE: FMVSS INTERPRETATION TEXT: MAY 4 1983 NOA-30 Mr. James E. Benson Sales Manager Boschung Company, Inc. 530 Armory Drive South Holland, Illinois 60473 Dear Mr. Benson: This is in reply to your letter of March 23, 1983, asking whether a stop lamp is required on a Boschung vehicle which has a top speed of 16 mph. You also asked for a copy of the "Rules for Manufacturer Standard Specs." The agency does not consider a vehicle, which cannot exceed 20 mph and has an abnormal configuration, to be a motor vehicle. These vehicles, typically, are highway maintenance and construction equipment, lane stripers, self-propelled pavers, sod handler, fork lift, and other similar vehicles. It would not appear, therefore, that the low-speed Boschung is a "motor vehicle." The question of whether it is required to have a stop lamp, therefore, is dependent upon the laws of the municipality in which it is operated. I assume the "Rules" you wish are the Federal motor vehicle safety standards. You should write the Superintendent of Documents, U.S. Government Printing Office, Washington, D.C. 20402, enclosing a check for $8, and ask for "Title 49 Code of Federal Regulations Parts 400 to 999." The safety standards are at Part 571, and you will find all other regulations in the 500 series which apply to motor vehicles and their manufacturers. If you have any further questions, we shall be happy to answer them. Sincerely,
Frank Berndt Chief Counsel March 23, 1983
National Highway Traffic Safety Admin. U. S. Dept. of Transportation Legal Council (Mr. Taylor Vinson) Rm. 5219 400 7th Street Southwest Washington, D.C. 20590 Dear sir: I would appreciate some information, regarding The Boschung vehicle, (literature enclosed). This unit is basically used off-road, however, at certain times it would be on the street. One that travels 16 mph does not have a stop light on it, but the faster vehicle (24 mph) does. My question is this, "Is a stop light required on the slower moving vehicle?" I will also appreciate your sending me a copy of the "Rules for Manufacturer Standard Specs". We look forward to hearing from you, regarding the stop light, and thank you, for your help.
Sincerely, BOSCHUNG COMPANY, INC.
James E. Benson Sales Manager
JEB/dd Enclosure
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ID: nht78-2.50OpenDATE: 01/20/78 FROM: AUTHOR UNAVAILABLE; F. Berndt for J. J. Levin, Jr.; NHTSA TO: The Bendix Corporation TITLE: FMVSS INTERPRETATION TEXT: This responds to Bendix Corporation's November 9, 1977, request for confirmation that S5.6.4 of Standard No. 121, Air Brake Systems, does not prohibit the use of a two-valve sequential means to release the parking brakes on a towed vehicle. I have enclosed for your information two interpretations that address this question, stating that a two-valve sequential release is permissible under S5.6.4. I have also enclosed a copy of an outstanding rulemaking proposal that would standardize the parking brake control as specified in the Society of Automotive Engineers Recommended Practice J680b. I am unable to advise you whether the National Highway Traffic Safety Administration intends to make final this proposal. I would also like to remind you of the requirement in S5.6.4 that "[the] control shall be identified in a manner that specifies the method of control operation." So long as different control arrangements are used, it is critical that the means of operation be clearly marked. |
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ID: nht95-3.41OpenTYPE: INTERPRETATION-NHTSA DATE: July 13, 1995 FROM: George E. Walton -- International Manufacturer's Consultants Inc. TO: Mr. John Womack -- Acting Chief Counsel, NHTSA TITLE: Reference: Federal Motor Vehicle Safety Standards No. 205, Glazing Materials - Passenger Cars, Multipurpose Vehicles, Motorcycles, Trucks and Buses. ATTACHMT: ATTACHED TO 08/04/95 LETTER FROM JOHN WOMACK TO GEORGE W. WALTON (REDBOOK 2; STD. 205) TEXT: Dear Mr. Womack: We represent a client who wishes to obtain your written comment on the use of the following glazing material in a motor vehicle: Our client wishes to use laminated "AS-1" Glass for motorcycle windshields. A motorcycle is described as a "Motor Vehicle", and the FMVSS-205 standard indicates by reference in the ANSI Z26.1 standard that "AS-1" glazing for use "Anywhere in a Motor Vehicle". Our client would like to have your written comment prior to producing several thousand motorcycle windshields from AS-1 glazing. Would you kindly address your comment to the undersigned. |
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ID: nht95-5.20OpenTYPE: INTERPRETATION-NHTSA DATE: July 13, 1995 FROM: George E. Walton -- International Manufacturer's Consultants Inc. TO: Mr. John Womack -- Acting Chief Counsel, NHTSA TITLE: Reference: Federal Motor Vehicle Safety Standards No. 205, Glazing Materials - Passenger Cars, Multipurpose Vehicles, Motorcycles, Trucks and Buses. ATTACHMT: ATTACHED TO 08/04/95 LETTER FROM JOHN WOMACK TO GEORGE W. WALTON (REDBOOK 2; STD. 205) TEXT: Dear Mr. Womack: We represent a client who wishes to obtain your written comment on the use of the following glazing material in a motor vehicle: Our client wishes to use laminated "AS-1" Glass for motorcycle windshields. A motorcycle is described as a "Motor Vehicle", and the FMVSS-205 standard indicates by reference in the ANSI Z26.1 standard that "AS-1" glazing for use "Anywhere in a Motor Vehicle". Our client would like to have your written comment prior to producing several thousand motorcycle windshields from AS-1 glazing. Would you kindly address your comment to the undersigned. |
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ID: nht71-1.6OpenDATE: 08/09/71 FROM: AUTHOR UNAVAILABLE; Robert L. Carter; NHTSA TO: Holen Company TITLE: FMVSS INTERPRETATION TEXT: This is in reply to your letters of June 30 and August 2 on the subject of the applicability of Standard No. 210 to multipurpose passenger vehicles, trucks, and buses as amended by notice of March 4, 1971 (36 F.R. 4291). The standard applies to these vehicles effective July 1, 1971, even though the heading published in the Register refers only to passenger cars. The application of the standard is controlled by the application section, S2, and not by the heading of the standard. The heading only reflects the substance of the application section and should automatically change whenever the application is changed. Through oversight, the Federal Register was given no instructions as to handing changes, and therefore inserted the old heading into the March 4 notice. Since the heading has no substantive role, and since the amendment is only in effect until the revised Standard No. 210 becomes effective January 1, 1972, we have not requested the Federal Register to alter the heading. I hope this is responsive to your question. |
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ID: nht72-2.47OpenDATE: 02/14/72 FROM: AUTHOR UNAVAILABLE; Richard B. Dyson; NHTSA TO: North Carolina Automotive Wholesalers Association, Inc. TITLE: FMVSS INTERPRETATION TEXT: This is in reply to your letter of January 19, 1972, concerning brake fluids. A revised Federal Motor Vehicle Safety Standard No. 116, effective March 1, 1972, was published on March 24, 1971 (36 F.R. 11987), based upon a proposal published on September 30, 1970 (35 F.R. 1522O). I enclose a copy of the proposal and the rule for your information: the preambles to these notices explains the relationships between the DOT and SAE terminology in identification of brake fluid. In response to your specific questions, brake fluid must conform to Standard No. 116 at the time it is sold to the ultimate purchaser. This means that the manufacturer is responsible for manufacturing fluid that meets Standard No. 116, and the package and retail seller for insuring that the fluid continues to conform until the time of sale. Brake fluid manufactured before March 1, 1972, may be sold until the supply is exhausted, and no relabeling is necessary. |
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ID: nht72-6.2OpenDATE: 03/23/72 FROM: AUTHOR UNAVAILABLE; Richard B. Dyson; NHTSA TO: The Daystar Motor Homes Inc. TITLE: FMVSR INTERPRETATION TEXT: This is in reply to your letter of February 4 asking for copies of regulations applicable to a "motor home" you wish to manufacture. I enclose a copy of the National Traffic and Motor Vehicle Safety Act of 1966, the basic statute setting forth your obligations as a manufacturer, and the authority for all applicable regulations. A publication titled "Federal Motor Vehicle Safety Standard and Other Regulations" is available from the Superintendent of Documents, Government Printing Office, Washington, D. C. 20402. The price of $ 8.00 includes a subscription of up to one year of supplements. The Federal standards and regulations also appear in Title 49 of the Code of Federal Regulations (Title 19 for the important regulations), generally available at law libraries. Amendments and proposals are published, when issued, in the Federal Register. If you have any questions after obtaining and receiving these materials I will be happy to answer them for you. A "motor home" for your information, is defined as a "multipurpose passenger vehicle" under the Federal standards. |
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.