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: nht75-6.33OpenDATE: 07/10/75 FROM: AUTHOR UNAVAILABLE; Richard B. Dyson; NHTSA TO: Cooney Equipment Company TITLE: FMVSR INTERPRETATION TEXT: Your letter of June 17, 1969, to Mr. Donald Morrison of the Bureau of Motor Carrier Safety, concerning switching arrangements for running lamps, has been transferred to this Office for consideration and reply. Enclosed for your information is a copy of Federal Motor Vehicle Safety Standard No. 108 on lighting requirements for motor vehicles. This standard is applicable to new vehicles manufactured on or after the effective date of January 1, 1969. Special wiring requirements, such as lamp switching arrangements, are included in paragraphs S3.4 through S3.4.7 of the standard. We do not completely understand your usage of the term "running lights." If you are referring only to tail lamps, your attention is invited specifically to paragraph S3.4.3 of the standard which is quoted as follows: "As a minimum the tail lamps shall be illuminated when the headlamps are illuminated except when the headlamps are being flashed." The switching arrangements for other "running lights," such as clearance lamps and identification lamps, are at the option of the vehicle manufacturer. Thank you for writing. |
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ID: nht92-9.38OpenDATE: January 24, 1992 FROM: Larry J. French -- President and CEO, Magnascreen TO: Office of Chief Counsel, NHTSA TITLE: Reference: 49 CFR, Part 571, Docket No. 91-11, Notice 2, RIN2127-AD81, Federal Motor Vehicle Safety Standards; Rearview Mirrors - Reflectance ATTACHMT: Attached to letter dated 3/26/92 from Paul J. Rice to Larry J. French (A39; Std. 111) TEXT: Magnascreen is presently developing electronically controlled dimmable (day/night) rearview mirror products for motor vehicles. Magnascreen has reviewed the revised Code of Federal Regulations, Title 49, 571.111, standard number 111, for motor vehicle rearview mirror requirements referenced above. Upon review, we are requesting that the NHTSA comment on the validity of Magnascreen's interpretation which follows: "When a multiple reflectance level mirror is not powered by the vehicle power source, the reflectance of the mirror can be returned to a minimum of 35% reflectance (either automatically or by driver operated controls) USING AN ALTERNATE POWER SOURCE." (A power source other than the one intended to (illegible) the mirror.) This interpretation allows multiple reflectance mirror designs to use an alternate power source to achieve the specified failsafe operation called out in CFR 49, 579.111, para. S11, Rearview Mirrors. Your timely response will be appreciated, as this interpretation impacts Magnascreen's mirror product designs. |
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ID: 1866yOpen Mr. Rod Willaredt Dear Mr. Willaredt: This is in reply to your letter to Taylor Vinson of this Office, received by FAX on May l7, l989. You have developed a "safety light" that displays right and left turn signals, "and when the caution light/emergency light appears, the formation of such lights indicate a diamond". The device appears intended for installation on large trucks or trailers. The turn signal lamps are supplementary to a vehicle's original equipment turn signal lamps. I assume that the caution/emergency lamp to which you refer is what we call a hazard warning signal, sometimes known as a 4-way flasher. You have asked for written approval of this device. This agency has no authority to "approve" or "disapprove" any motor vehicle or item of equipment. We can, however, advise as to the relationship of equipment to applicable Federal motor vehicle safety standards. I enclose copies of representative letters covering other auxiliary rear lighting for large trucks, such as wide-turn and U-turn indicators, and their relationship to Motor Vehicle Safety Standard No. l08, the National Traffic and Motor Vehicle Safety Act, and State law. These principles are applicable to your safety light as well. If you have any further questions, we shall be happy to answer them. Sincerely,
Stephen P. Wood Acting Chief Counsel Enclosures /ref:l08 d:6/l9/89 |
1970 |
ID: nht90-2.41OpenTYPE: INTERPRETATION-NHTSA DATE: 05/07/90 FROM: JOHN W. GARRINGER TO: STEPHEN P. WOOD -- NHTSA TITLE: NONE ATTACHMT: ATTACHED TO LETTER DATED 6/18/90 FROM PAUL JACKSON RICE -- NHTSA TO JOHN W. GARRINGER; A35; STANDARD 205; LETTER DATED 02/01/90 FROM JOHN W. GARRINGER TO TERRY M. GERNSTEIN TEXT: I am writing this letter to find out if the item that I am in the process of patenting is against the law. It is put on the inside, bottom part of the windshield, on any type vehicle that has a windshield. It is made only for safety, so that you can see better when you are driving on sunny days. It is made to cover the hood area that the driver sees only. It stops the suns glare which is reflected from the hood, from coming into the drivers eyes. This i tem makes it better for the driver to see to drive. I also think it would help to prevent a lot of daytime accidents. The material is four times the darkness of the plastic that is enclosed. This is to perform a better job reflecting the glare. I have also enclosed all items that I have pertaining to this product. If this product is against the law, Federal or State, please send me a copy of the law. Also, please send me a list of the states that it is legal and a list of states that it is illegal in. Please let me know what it is that I would have to do to get it so that this product is legal. |
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ID: nht74-1.32OpenDATE: 05/16/74 FROM: AUTHOR UNAVAILABLE; E. T. Driver; NHTSA TO: Lt. Commander Robert H. Weldman, Jr. COPYEE: LARSON; RANADER TITLE: FMVSS INTERPRETATION TEXT: This response to your letter of April 17, 1974, to the Department of Transportation requesting information on standards for (Illegible Word) Lighting systems. We have me record of your (Illegible Words) In answer to your specific questions -- 1. "Are there any federal or state regulations which specify sealed beam headlamps?" Yes, this requirement has been effective either by Federal or State standards for more than three decades. 2. "Are both acceptable?" A replacable bulb type headlamp is not acceptable. 3. "Is amber a permissible headlight (Illegible Word) No, headlight must white light. 4. "Is white mandatory for backup lights?" Yes, white is mandatory. Sincerely, ATTACH. APRIL 17, 1974 U.S. Department of Transportation, Attn: Federal Standards for Automobiles. Dear Sirs, I wrote you on 12 February 1974 to ask for information on Federal and state standards for automobile lighting systems. I have received no reply, so herewith a repeat of my request: are there any federal or state regulations which specify sealed beam headlamps, or are bulbs acceptable? Is amber a permissible headlight color? Is white mandatory for backup lights? I will appreciate any information you can give me. Sincerely, Robert H. Weidman, Jr. -- LCDR USN, Box 33 B753, FPO NEW YORK 09540 |
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ID: nht78-2.32OpenDATE: 04/05/78 TO: Truck Body and Equipment Association Inc. TITLE: FMVSR INTERPRETATION TEXT: This responds to your February 21, 1978, letter asking whether section 567.5(c)(7) of Part 567, Certification, requires a manufacturer to use all of the described statements on its certification label. The answer to your question is no. That section provides that the listed certification statements are to be used as appropriate. Therefore, it is anticipated that a manufacturer will select for inclusion on its certification labels only those certification statements in subparagraph (c)(7) that are appropriate for the certification of its vehicles. |
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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: nht74-4.16OpenDATE: 07/17/74 FROM: AUTHOR UNAVILABLE; Richard B. Dyson; NHTSA TO: Elgin Sweeper Company TITLE: FMVSR INTERPRETATION TEXT: This is in reply to your letter of June 7, 1974, asking whether NHTSA Certification requirements (40 CFR Parts 567, 568) apply to the mounting of a device called the Elgin Eductor on a used truck. The NHTSA does not consider the Certification requirements to apply to the mounting of a new truck body (based on the information you provide, this includes the Elgin eductor) on a used truck chassis. We consider additions to used chassis to be used vehicles under the National Traffic and Motor Vehicle Safety Act, and no certification is therefore required. |
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ID: nht72-6.49OpenDATE: 12/14/72 FROM: AUTHOR UNAVAILABLE; David Schmeltzer; NHTSA TO: Edgewood Motorcycle Shop TITLE: FMVSR INTERPRETATION TEXT: This is in reply to your letter of November 30, 1972, asking if you have to maintain a record of the tires you sell and register or is it sufficient to mail the requested information to the tire manufacturer or the tire manufacturer's designee. Under Part 574.8 of the Tire Identification and Record Keeping regulation (49 CFR Part 574) a tire dealer is recorded to submit the required information to the tire manufacturer or his designee but is not required to keep a separate record of the tires sold. |
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ID: nht73-3.1OpenDATE: 12/04/73 FROM: AUTHOR UNAVAILABLE; Richard B. Dyson; NHTSA TO: Adolph Kunasicwicz TITLE: FMVSR INTERPRETATION TEXT: Your request for information concerning the existence of penalties for removal of the required certification label from a motor vehicle has been forwarded to us by the Federal Trade Commission. The National Traffic and Motor Vehicle Safety Act requires that a certification label, which under NHTSA regulations includes the name of the manufacturer and the date of manufacture, be permanently affixed to the motor vehicle. Although removal of this lable does not carry a criminal penalty of either fine or imprisonment, a civil penalty of up to $ 1,000 is specified in certain situations. |
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.