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: nht70-2.22OpenDATE: 08/26/70 FROM: AUTHOR UNAVAILABLE; R. A. Diaz; NHTSA TO: International Manufacturing Company TITLE: FMVSS INTERPRETATION TEXT: This is in reply to your letter of August 12 to Mr. Toms requesting an interpretation of Federal Motor Vehicle Safety Standard No. 211 (Wheel Discs, Wheel Nuts, and Hub Caps). This standard does not prohibit projections per see on wheel equipment items; it prohibits winged projections. Thus there is no limitation on how far a cylindrical projection, for example, may extend beyond the outer edge of the tire. On the other hand, any winged projection is prohibited, even if recessed. I hope this answers your question. |
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ID: 3192yyOpen Mr. Martin L. Marinoff Dear Mr. Marinoff: This responds to your letter asking about Federal Motor Vehicle Safety Standard No. 105, Hydraulic Brake Systems. You stated that you believe the standard requires vehicles to have a warning light system that indicates loss of pressure or low fluid level in the braking system and asked if this belief is correct. Your understanding about Standard No. 105 is correct. I have enclosed a copy of that standard for your information. The requirements for brake system indicator lamps are set forth at section S5.3 of the standard. Sincerely,
Paul Jackson Rice Chief Counsel Enclosure /ref:105 d:l0/23/9l |
2008 |
ID: nht95-3.17OpenTYPE: INTERPRETATION-NHTSA DATE: June 15, 1995 FROM: Bryan G. Nelson -- Director, Health And Transporation Services, (Parents In Community Action Inc.) TO: Walt Myers -- NHTSA TITLE: NONE ATTACHMT: ATTACHED TO 9/14/95 LETTER FROM JOHN WOMACK TO BRYAN G. NELSON (RED BOOK 2; A43; PART 571.3) TEXT: Dear Mr. Myers: We spoke briefly about standards for School Buses and I wanted to get your written response. You stated that the school bus color was only a recommendation and not a federal requirement. That color requirements for school buses was up to individual states. I'd appreciate your written response. Thank-you for your assistance. |
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ID: nht72-5.26OpenDATE: 08/31/72 FROM: AUTHOR UNAVAILABLE; Richard B. Dyson; NHTSA TO: Truck Trailer Manufacturers Association TITLE: FMVSR INTERPRETATION TEXT: This is in response to your letter of August 18, 1972, enclosing threesample Certification labels. Each of the three labels contains a line for inserting the gross axle weight rating for four axles. You ask whether the lines representing intermediate axles may be deleted through the use of X's for vehicles that do not have such axles. The use of X's or similar markings to delete superfluous times is Certification labels of the type you enclose, is not prohibited by the Certification regulations. Consequently they may be used for vehicles having up to four axles. |
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ID: 005493drnOpenMr. D. R. Smith Dear Mr. Smith: This responds to your July 14, 2003, request for information whether Federal Motor Vehicle Safety Standard (FMVSS) No. 211, Wheel Nuts, Wheel Discs, and Hub Caps is still in effect. The answer is no. In a Federal Register notice of May 6, 1996, (61 FR 20172, copy enclosed) the National Highway Traffic Safety Administration rescinded FMVSS No. 211. The rescission took effect on June 5, 1996. I hope this information is helpful. If you have any further questions, please feel free to contact Dorothy Nakama of my staff at this address or at (202) 366-2992. Sincerely, Jacqueline Glassman Enclosure |
2003 |
ID: nht94-2.77OpenTYPE: INTERPRETATION-NHTSA DATE: May 10, 1994 FROM: Christopher A. Hart -- Acting Administrator, NHTSA; Signature by Stephen P. Wood TO: The Honorable Doug Bereuter -- U.S. House of Representatives TITLE: None ATTACHMT: Attached To Letter Dated 4/20/94 From Doug Bereuter To Christopher Hart (OCC-9916) And 1/1/94 (EST) Letter From Christopher A. Hart To Doug Bereuter TEXT: Dear Mr. Bereuter: Thank you for your recent letter concerning our rulemaking on compressed natural gas (CNG) vehicle fuel systems and fuel containers. Please be assured that I will keep you fully apprised of the rulemaking's status. I share your concern that the rulemak ing be completed expeditiously as possible and appreciate your interest in this matter. Thank you for your patience. Sincerely, |
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ID: nht91-6.34OpenDATE: October 23, 1991 FROM: Paul Jackson Rice -- Chief Counsel, NHTSA TO: Martin L. Marinoff TITLE: None ATTACHMT: Attached to letter dated 7-30-91 from Martin L. Marinoff to NHTSA (OCC 6511) TEXT: This responds to your letter asking about Federal Motor Vehicle Safety Standard No. 105, Hydraulic Brake Systems. You stated that you believe the standard requires vehicles to have a warning light system that indicates loss of pressure or low fluid level in the braking system and asked if this belief is correct. Your understanding about Standard No. 105 is correct. I have enclosed a copy of that standard for your information. The requirements for brake system indicator lamps are set forth at section S5.3 of the standard. |
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ID: nht69-1.46OpenDATE: 09/10/69 FROM: AUTHOR UNAVAILABLE; C. A. Baker; NHTSA TO: Blue Bird Body Company TITLE: FMVSS INTERPRETATION TEXT: Thank you for your letter of August 8, 1969, concerning the operation of red warning lamps on school buses. Paragraph S3.1.3.2 (b)(2) of Federal Motor Vehicle Safety Standard No. 108 appears to require that the red warning lamps be e-nergized when a school bus door is opened for any purpose. However the intent of the standard is that the red warning lamps be energized only when the bus entrance door is open for the admission or discharge of passengers (i.e. that the red lamps be activated automatically only after manual energization of the amber lamps), and many manufacturers have, in our view, correctly go interpreted S3.1.3.2 (b)(2). |
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ID: nht90-3.61OpenTYPE: Interpretation-NHTSA DATE: August 20, 1990 FROM: Harry B. Skinner -- Chief, Traffic Engineering Division, Office of Traffic Operations, NHTSA TO: Oliver M. Sprangers -- A. T. Kearney, Inc. TITLE: Re HTO-21 ATTACHMT: Attached to letter dated 6-27-90 from Olivier M. Sprangers to James T. Brooks; Also attached to letter dated 1-8-91 from Paul J. Rice to Olivier M. Sprangers (A37; Std. 125) TEXT: We have received your letter of June 27 and forwarded your request to the U.S. Department of Transportation's National Highway Traffic Safety Administration (NHTSA) for response. Personnel from the NHTSA will be able to better evaluate your safety device than our staff member, Mr. James T. Brooks. Your interest in promoting highway safety is greatly appreciated. If we can be of further assistance, please let us know. |
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ID: nht89-1.97OpenTYPE: INTERPRETATION-NHTSA DATE: 06/08/89 FROM: ROBERT J. KNAUFF -- APPLIED RESEARCH AND DESIGN TO: KATHLEEN DEMETER -- ASSISTANT CHIEF COUNSEL FOR GENERAL LAW U.S. DEPARTMENT OF TRANSPORTATION TITLE: NONE ATTACHMT: ATTACHED TO LETTER DATED 07/24/89 FROM STEPHEN P. WOOD -- NHTSA TO ROBERT KNAUFF; REDBOOK A33; FMVSS 108; LETTER DATED 08/16/88 FROM RICHARD H. SCHULTZ -- AMERICAN PULSE LIGHTS INC TO ROBERT KNAUFF; LETTER DATED 12/07/87 FROM RICHARD H. SCHULTZ -- AMERICAN PULSE LIGHTS TO ROBERT J. KNAUFF TEXT: Dear Ms. DeMeter: Confirming our phone conversation relating to your letter dated May 26, 1989, this is to confirm that you have my permission to use the information marked "confidential" in determining if my collision avoidance system will conform to the existing laws. If you have any other questions, please feel free to contact me. Professionally, |
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.