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 |
|---|---|
ID: nht73-6.8OpenDATE: 04/13/73 FROM: AUTHOR UNAVAILABLE; Robert L. Carter; NHTSA TO: R. W. Lillie & Company TITLE: FMVSS INTERPRETATION TEXT: 99:(ILLEGIBLE TEXT) Director DIVISION OF MOTOR CARRIER SAFETY DEPARTMENT OF TRANSPORTATION 400 SEVENTH STREET, S.W. WASHINGTON, D.C. 20590 ENC. R. W. LILLIE & CO. April 3, 1973 Robert L. Carter United States Department of Transportation National Highway Traffic Safety Administration Dear Mr. Carter: Thank you very much for your letter of March 29, 1973 on Motor Vehicle Safety Standards and the very useful information it included. Even though you said that Standard NO. 116 includes silicone brake fluids, the standard itself on the first page under section S-3 says that it does not apply to petroleum based and silicone based brake fluids. Perhaps you can further enlighten me. Regarding Plastic Fuel Tanks, the proposed rule making notice Docket No. MC-34 - Notice 71-26 must have been followed by some further action. Any ideas on this? Very truly yours, R. W. Lillie |
|
ID: nht93-3.39OpenDATE: May 7, 1993 FROM: John W. Schumann -- Manager of Research and Development, Department of Water and Power, The City of Los Angeles TO: All Interested Parties COPYEE: Jeffrey S. Silverstone TITLE: Attachment A -- Request for Proposal (RFP) for Acquisition of Electric Vehicles ATTACHMT: Attached to letter dated 1/11/94 from John Womack to Richard J. Dessert (A42; Part 555) and letter dated 5/28/93 from Richard J. Dessert to NHTSA Administrator (OCC-8731) TEXT: Enclosed for your information and potential response is an RFP for acquisition of electric vehicles. The response deadline for this RFP is June 1, 1993. If it is your intention to respond to this RFP, please provide five copies of your response and deliver to: Los Angeles Department of Water and Power Mr. Jeffrey S. Silverstone Attn: Electric Vehicle RFP 111 North Hope Street, Room 1129 Los Angeles, California 90012-2694 Or mail to: Los Angeles Department of Water and Power Mr. Jeffrey S. Silverstone Attn: Electric Vehicle RFP P.O. Box 111, Room 1129 Los Angeles, California 90051-0100 If additional information is needed, please contact Mr. Jeffrey S. Silverstone at (213) 580-3725. |
|
ID: nht71-1.25OpenDATE: 07/00/71 FROM: AUTHOR UNAVAILABLE; Lawrence R. Schneider; NHTSA TO: Recreational Vehicle Institute, Inc. TITLE: FMVSS INTERPRETATION |
|
ID: nht74-5.55OpenDATE: 08/20/74 FROM: AUTHOR UNAVAILABLE; R. B. Dyson; NHTSA TO: Toyda Gosei Co., Ltd. TITLE: FMVSS INTERPRETATION TEXT: This responds to your August 8, 1974, question whether the effective date of Standard No. 106-74, Brake hoses, is September 1, 1974, for hose (and fittings) and March 1, 1975, for nose assemblies. Your interpretation is correct. The standard requires conforming hose (and fittings) as of September 1, 1974. It requires conforming assemblies (including the label band) only on March 1, 1975, and thereafter. |
|
ID: nht78-3.30OpenDATE: 12/13/78 FROM: AUTHOR UNAVAILABLE; J. J. Levin, Jr.; NHTSA TO: Cars & Concepts, Inc. TITLE: FMVSS INTERPRETATION TEXT: This responds to your December 4, 1978, letter concerning the applicability of Safety Standard No. 205, Glazing Materials, to applied windshield tint bands. I am enclosing copies of two previous letters of interpretation by the agency regarding polyester films that appear to be similar to the product you describe. I think these letters will answer all of your questions. If not, please contact Hugh Oates of my office at 202-426-2992. |
|
ID: nht68-4.21OpenDATE: 11/18/68 FROM: AUTHOR UNAVAILABLE; R. Brenner for William Haddon, Jr., M.D.; NHTSA TO: General Motors Corporation TITLE: FMVSS INTERPRETATION TEXT: Thank you for your letter of September 25, 1968, regarding Federal Motor Vehicle Safety Standard No. 211 and the use of hexagonal wheel nuts. The requirement of this standard that wheel nuts, hub caps and wheel dirce "shall not incorporate vinged projections" apparently applied to all wheel nuts, whether hexagonal or otherwise. I agree that clarification of the standard is needed, but the method of accomplishing this is yet to be resolved. I have asked the Motor Vehicle Safety Performance Service to look into this problem immediately and to take the neccessary steps to relieve any undue burdens. |
|
ID: 11719MLVOpen Mr. Don Bearden Dear Mr. Bearden: This responds to your letter of April 1, 1996, requesting confirmation that a vehicle certified as a "passenger car" would not be subject to the labeling requirements of 49 CFR 575.105. You are correct. Section 575.105(b) states that the requirements apply only to "multipurpose passenger vehicles." I hope this information has been helpful. If you have other questions or need some additional information, please contact Mary Versailles of my staff at this address or by phone at (202) 366-2992. Sincerely,
Samuel J. Dubbin Chief Counsel ref:575.105 d:4/18/96
|
1996 |
ID: nht94-4.39OpenTYPE: INTERPRETATION-NHTSA DATE: September 29, 1994 FROM: Alberto Negro -- Chief Executive Officer, Fiat Auto R&D U.S.A TO: John Womack -- Acting Chief Counsel, NHTSA TITLE: 49 CFR Part 583 - Automobile Parts Content Labeling Request for Interpretation ATTACHMT: ATTACHED TO 3/14/95 LETTER FROM PHILIP R. RECHT TO ALBERTO NEGRO (PART 583; REDBOOK (2)) TEXT: I am writing to ask that you verify whether the 1000 unit threshold of 49 CFR 583.5(g) applies to the Alfa Romeo and Ferrari marques separately or collectively, as those marques are both owned by Fiat S.p.A. Fiat S.p.A. is the stockholder of Fiat Auto S. p.A., which produces Alfa Romeo cars, and of Ferrari S.p.A. which produces Ferrari cars. I thank you for your consideration and I remain at your disposal for all additional information that you require. |
|
ID: nht88-3.72OpenTYPE: INTERPRETATION-NHTSA DATE: 10/17/88 FROM: MELVIN KREWALL -- DIRECTOR TRANSPORTATION SECTION FINANCIAL SERVICES DIVISION OKLAHOMA STATE DEPT OF EDUCATION TO: CHIEF COUNSEL NATIONAL HIGHWAY TRAFFIC SAFETY ADMIN. TITLE: NONE ATTACHMT: ATTACHED TO LETTER DATED 03/31/89 FROM ERIKA Z. JONES -- NHTSA TO MELVIN KREWALL, REDBOOK A33 (2), PART 571.3 TEXT: Dear Sir: The State Superintendent of Public Instruction for the State of Oklahoma asked me to submit two questions to your office for your consideration. 1. May a transit coach-type vehicle, manufactured prior to April 1, 1977, be used on a public school bus route to transport students to and from school? 2. What must be done to a transit coach-type vehicle to bring it into compliance as a standard Type "D" school bus? We would appreciate a reply at your earliest convenience. Sincerely, |
|
ID: nht94-4.81OpenTYPE: INTERPRETATION-NHTSA DATE: November 15, 1994 FROM: Philip R. Recht -- Chief Counsel, NHTSA TO: Clay F. West -- Garvey, Schubert & Barer TITLE: None ATTACHMT: ATTACHED TO LETTER DATED 11/1/94 FROM CLAY F. WEST TO NHTSA CHIEF COUNSEL TEXT: This responds to your letter of November 1, 1994, requesting information on any rules or standards applicable to a "windshield cleaning device." As your letter describes, "(t)he product is a clear strip which is adhered to the windshield of an automobile . The action of the wiper blades passing over the device causes the wiper blades to function more effectively." I am enclosing a copy of a May 29, 1992 letter to Mr. John J. Jacoby concerning a similar device. I believe this letter contains the information you need. If you have any other questions, please contact Mary Versailles of my staff at this address or by phone at (202) 366-2992. |
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.