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: nht95-4.23OpenTYPE: INTERPRETATION-NHTSA DATE: September 18, 1995 FROM: Ben Ray TO: John Womack TITLE: NONE ATTACHMT: ATTACHED TO 11/28/95 LETTER FROM Samuel J. Dubbin to Ben Ray (A43; Std. 121; Part 571.7) TEXT: Dear Mr. Womack, This letter is in regards to brake adjusters for log trailers. I am currently building log trailers for resale. These trailers are used mostly in the woods transporting logs from the woods to the mills. I am using used axles under them. These used ax les already have regular brake adjusters on there when I buy them. What I would like is some paperwork saying if this is alright to use these regular brake adjusters instead of automatic adjusters. I was referred to you by Richard Carter, (202-366-5274 ). Mr. Carter said there was a fine line in regards to which one to use because of the fact that the axles that I use are used. He also said being that the trailer is not considered new, that I could use a regular brake adjuster. I would really apprec iate it if you could send me some paperwork stating that it is alright to use these regular brake adjusters. If you should have any questions, please call me at home, 901-925-2727 or work, 901-925-1893. Sincerely, |
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ID: 12259.drnOpen Mr. Andreas Geis Dear Mr. Geis: Thank you for your letter about Standard No. 104, Windshield Wiping and Washing Systems. You note several typographical errors in your version of the standard that you would like us to correct. The version of the standard to which you refer is not the National Highway Traffic Safety Administration's version. The official version of Standard No. 104 is set forth in Title 49 of the Code of Federal Regulations, Parts 400 to 999, dated October 1, 1995 (copy enclosed). This version does not contain the errors you found. Please note that English system measurements in Standard No. 104 have been converted to the metric system. The metric measurements took effect on March 14, 1996. The conversions are not intended to change the stringency of Standard No. 104. If you have further questions or need additional information, please contact Dorothy Nakama of my staff at (202) 366-2992. Our fax number is (202) 366-5820. Sincerely, John Womack Enclosure |
1996 |
ID: nht71-2.3OpenDATE: 02/10/71 FROM: R.A. DIAZ -- NHTSA; SIGNATURE BY CLUE D. FERGUSON TO: The Yokohama Rubber Company Inc. TITLE: FMVSR INTERPRETATION TEXT: This will acknowledge your letter of December 30, 1970, requesting exemption from the requirements of Section 374,4, concerning the location of the required labeling between the maximum section width and the based, of Regulation Fact 374. Tire Identification and Recordkeeping. Your request is being(Illegible Word) as a petition for rulemaking under @ 353.551 of title 42 and by way of this letter is denied. The National Highway Traffic Safety Administrative is requiring the location of the identification number because the maximum sections width and the based for two reasons. As you have currently cited the location is such as this labeling will not be remove in the retreading(Illegible Words). The second reason is that such a location will provide the maximum protection to(Illegible Word) that the number is not scuffed or(Illegible Word) off during the operation. In view of these reasons, you are not allowed to put the identification number in the space above the regular section width. Your question concerning the height of the "DOT" for motorcycle tires is not applicable at this time. The symbol "DOT" cannot be used as motorcycle tires until there is an applicable standard. The(Illegible Word) for the standard covering these tires will be issued later this calender year and probably will not be effective until January 1, 1972. |
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ID: nht91-3.37OpenDATE: May 3, 1991 FROM: Richard E. Wright -- Richard E. Wright Associates TO: Chief Council, NHTSA TITLE: None ATTACHMT: Attached to letter dated 7-1-91 from Paul Jackson Rice to Richard E. Wright (A38; Std. 205) TEXT: As a glass consultant, I periodically get asked questions concerning the use of safety glazing materials. A question arose recently concerning the use of tempered glass products in motor homes (self-contained motorized vehicles) and mobile homes (non-motorized travel trailers, etc.). The area of concern is interior applications (not the windows to the exterior), namely shower doors, tub enclosures, interior partitions, mirrors, etc. When safety glazing products (tempered or laminated glass, plastics) are used in each of these applications, do they have to meet the architectural test requirements (CPSC 16 CFR 1201/ANSI Z97.1) or the automotive test requirements (ANSI Z26.1)? To my knowledge, you are the governing body for use of safety glazing materials in vehicles and, therefore, have the ability to give me an official and legally binding ruling on my question. If this is not true, please let me know who I should contact. If you need any further clarification of my question or wish to discuss this topic by phone, please call me. I would appreciate knowing that this letter has been received and approximately how long it will take to get a written response. Thank you for your time and consideration. |
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ID: nht91-1.14OpenDATE: January 5, 1991 FROM: Chris Lawrence -- Chang & Lawrence TO: August L. Burgett -- Safety Standards Engineer, NHTSA TITLE: None ATTACHMT: Attached to letter dated 3-21-91 from Paul Jackson Rice to Chris Lawrence (A37; Std. 108; VSA 108(a)); Also attached to letter dated 8-17-89 from Stephen P. Wood to Alan S. Eldahr (VSA 108(a)(2)(A)) TEXT: I got your name from Mr. Patrick Maguire, Director of the Minnesota Trade Office in Taiwan. He said you might be able to answer questions I have concerning safety regulations for automobiles in the United States. I am considering producing a new product, an electronic sign board for cars, that would display messages on the outside of the vehicle. The driver would select one of several pre-programmed messages by voice command; a voice recognition unit on the sign board would interpret the command and initiate display of the appropriate pre-programmed message. A voice output unit would confirm that the right message was selected by announcing the fact on a voice output unit. My questions concern safety regulations that would restrict the use of lights to form messages on the outside of cars or from a window. The "Federal Register" (Standard 108 of Part 571 of Chapter 49) explains what lamps are specifically required on motor vehicles, and states that additional lamps that impair the effectiveness of the required lamps are prohibited. What is meant by "impairing the effectiveness of the required lamps"? And are there restrictions about what can be mounted in a window of a vehicle? Your assistance is greatly appreciated. |
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ID: nht91-5.1OpenDATE: July 16, 1991 FROM: Vel McCaslin -- Director, Grace After School TO: Mary Versailles -- United States Department of Transportation TITLE: None ATTACHMT: Attached to letter dated 9-6-91 from Paul Jackson Rice to Vel McCaslin (A38; Part 571.3) TEXT:
Please refer to the attached letter, last sentence in paragraph 2, from Paul Jackson Rice dated May 29, 1991. In order for you all to determine if we would be considered a school or school-related event, let me explain what Grace After School does. We operate under the auspicies of Grace Presbyterian Church from 3:00 p.m. until 6:00 p.m. daily. Our 3 vans (15 passenger) pick up children Kindergarten through 5th grade from three different area schools and bring them over to Grace Church. We provide snacks, have a period of about 1 hour for homework, and then go into acitivities like roller skating, art, music, and religion classes. We also have Ballet and Gymnastics here at the Church if they wish to participate. These children are from single parent families or working parents' children. We do accept Grace School children into our program but they are already here at the Church and need no transportation. I am enclosing one of my brochures for you to view. Please accept my many thanks for all your kind help in this manner.
Attachment Grace After School Brochure. (Text and graphics omitted.) Attachment Letter dated 5-29-91 from Paul Jackson Rice to Vel McCaslin. (Text omitted.) |
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ID: nht72-6.3OpenDATE: 10/06/72 FROM: EUGENE B. LASKIN FOR FRANCIS ARMSTRONG -- NHTSA TO: Clay Equipment Corporation TITLE: FMVSR INTERPRETATION TEXT: This is in reply to your letter of September 5, 1972, in which you enclose a copy of your brochure describing a "Honey Wagon" and ask what our requirements are. The "Honey Wagon" described in your brochure appears to be manufactured primarily for off-road use. The National Traffic and Motor Vehicle Safety Act and the Federal Motor Vehicle Safety Standards do not apply to off-road use vehicles. If you have further questions, I will be pleased to answer them. |
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ID: nht74-1.28OpenDATE: 07/15/74 FROM: C. BAKER FOR E. T. DRIVER -- NHTSA TO: Stanley Electric Co., Ltd. COPYEE: L. C. OWEN TITLE: FMVSS INTERPRETATION TEXT: This is in reply to your letter of June 27 concerning the location of motorcycle turn signal lamps relative to a combination stop lamp and reflex reflector. The minimum edge to edge separation distance specified in Table IV of FMVSS No. 108 for motorcycle turn signal lamps is to be measured from the edge of the illuminated surface of both lamps. The answer to your question 2 is therefore applicable, "2. edge to edge of tail and stop lamp so drawn in sketch C?" |
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ID: nht68-3.23OpenDATE: 04/16/68 FROM: AUTHOR UNAVAILABLE; David A. Fay; NHTSA TO: Bayerische Motoren Werke TITLE: FMVSS INTERPRETATION TEXT: Thank you for your letter of February 21, 1968, to Mr. J. E. Leysath of this Bureau, concerning the use of tubular type bulbs in license plate lamps. Motor Vehicle Safety Standard No. 108 requires that license plate lamps conform to Society of Automotive Engineers (SAE) Standard J587b. SAE J587b in turn requires that bulbs and bulb sockets conform to SAE Standards J573b and J567b, respectively. Since tubular type bulbs and sockets for these bulbs do not conform to these SAE Standards, their use in license plate lamps would not be permitted under the requirements of Standard No. 108. Thank you for writing. |
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ID: 21376.ztvOpenMr. Ray Lugo Dear Mr. Lugo: This is in reply to your request of February 16, 2000, asking our views on lamps mounted on the front of vehicles that would indicate when the brakes are applied. I enclose copies of two notices that we published in the Federal Register which address this subject. The first is a notice dated December 13,1996, in which we requested comments from the public on four signaling ideas, one of which was front brake lamps (61 FR 65510; see text beginning on page 65515). The second is a notice published on November 4, 1998 (63 FR 59482; see text on page 59486 and beginning on page 59491) reporting the public's comments and our conclusions. Sincerely, |
2000 |
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.