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: nht88-4.22OpenTYPE: INTERPRETATION-NHTSA DATE: 12/01/88 EST FROM: ERIKA Z. JONES -- NHTSA CHIEF COUNSEL TO: M. IWASE -- TECHNICAL ADMINISTRATION DEPT. - KOITO MFG. CO. LTD. TITLE: NONE TEXT: This is to provide you with a clarification of my letter to you dated March 16, 1988. Your second question was whether the minimum edge to edge separation distance between turn signal lamps and tail/stop lamps is required on a rear lighting array for mo torcycles. I responded that "The answer is yes, and the separation distance you have depicted in your drawings appears to comply with this requirement." In actuality, the agency has required this separation only where a single motorcycle stoplamp/taillamp is mounted on the vertical centerline, and not when dual lamps are mounted on either side of the vertical centerline, the configuration depicted in you r letter of January 25, 1988. Therefore, I am advising you that there is no legal requirement that the 4-inch separation distance be maintained in the configurations you depicted, and that we appreciate your continuing efforts to understand and comply w ith Federal Motor Vehicle Safety Standard No. 108. I enclose a copy of a letter from this Office dated November 21, 1984, which explains our views on motorcycle rear lighting configurations in more detail. Enclosure |
|
ID: nht90-1.99OpenTYPE: Interpretation-NHTSA DATE: April 5, 1990 FROM: Richard E. Portors -- Vice President and General Manager, Royale Limousine Manufacturers TO: Zachary R. Fraser -- NHTSA TITLE: None ATTACHMT: Attached to letter dated 8-30-90 from P.J. Rice to R.E. Portors (A36; Std. 108) TEXT: Please give me an advisory on my understanding of requirement 571.108 - S4.1.1.41 high mounted stop lamps section (a) projected area of not less than 4 1/2 square inches. The 90 Cadillac stop lamps measure 6 sq. inches of area. When installing a boomerang TV antenna the shaft area displaces 1.125 sq. inch of area, this would leave an exposed area of 4 7/8" of light and would exceed the minimum requirements of section (a) . Also, section (b) would not be affected by the boomerang. Without window glazing, section (c) would not be affected either. I feel the boomerang antenna positioned properly would not affect the requirements of 571.108. Please advise me on your findings as soon as possible. Attached is a copy of the Federal Register, section 571.108, 49 CFR Ch. V (10-1-85- Edition), page 218 (text omitted) |
|
ID: nht91-5.51OpenDATE: September 17, 1991 FROM: Jeffrey P. Shimp -- Engineer, Fleet Engineering & Q.A., Transportation Department, Baltimore Gas and Electric TO: Mary Versailles -- NHTSA, Office of Chief Counsel TITLE: None ATTACHMT: Attached to letter dated 10-9-91 from Paul Jackson Rice to Jeffrey P. Shimp (A38; VSA S108(a)(2)(A)) TEXT: In order to better serve our customers, we have found it necessary to increase the size of our work crews from two men to three men in one of our departments. Due to the amount of material required for these crews, we have typically utilized (two passenger) cargo vans for this operation. In view of the above, we would like to install a third seat in our cargo vans (mini and/or short wheel base), which are delivered by the manufacturers as a certified completed vehicle. We would greatly appreciate it if you could provide a written response advising us on this issue so that we can be in compliance with the Federal Motor Vehicle Safety Standards and any other governing regulations. If I can be of any assistance to you, please feel free to contact me (301/281-3630).
|
|
ID: nht92-4.48OpenDATE: August 6, 1992 FROM: R.J. Misorski -- Director, Maintenance & Repair, Maersk Inc. TO: Legal Council, NHTSA COPYEE: A. Petrizzo, W. Drozd TITLE: None ATTACHMT: Attached to letter dated 8/21/92 from Paul J. Rice to R.J. Misorski (A39; Std. 108) TEXT: Attached is a copy of the Federal Register outlining your rule change that went into effect December 1, 1991. The new rule now requires a minimum of 12 square inches of lens area for rear stop or turn signals on vehicles over 80" wide, regardless of the separation between lamps. We feel that equipment manufactured prior to December 1991 would be exempt from this ruling. Our interpretation of this new rule is that it only applies to equipment that is manufactured after December 1, 1991. We would highly appreciate if you could confirm our understanding in writing in order that we may ensure compliance with our equipment fleet. Attachment Copy of page 20158 of the 5/15/90 Federal Register pertaining to 49 CFR Part 571, Federal Motor Vehicle Safety Standards; Lamps, Reflective Devices, and Associated Equipment (action: final rule). (Text omitted) |
|
ID: nht94-9.7OpenTYPE: Interpretation-NHTSA DATE: January 10, 1994 FROM: Adam A. Freund -- Manager, Testing Services, Standards Testing Laboratories, Inc. TO: Walter Myers -- Office of Chief Counsel, NHTSA TITLE: Table II Minimum Static; Breaking Energy (inch pounds) D.O.T. 119 ATTACHMT: Attached to letter dated 4/12/94 from John Womack to Adam A. Freund (A42; Std. 119) TEXT: Further to our telephone conversation of this date, please find enclosed a copy of subject matter for your perusal. As we had discussed I believe there is a typo in the highlighted columns marked respectively MOTORCYCLE and ALL 12 INCH OR SMALLER RIM SIZE. If I am correct the first column MOTORCYCLE should show a plunger diameter of 5/16" and the column marked ALL 12 INCH OR SMALLER RIM SIZE should show a plunger diameter of 3/4". I would appreciate your qualifying my interpretation of above subject matter. If my interpretation is incorrect, please advise me how the respective columns should be marked. Standards Testing Laboratories, Inc. would greatly appreciate any expedited consideration you may allow us on this request.
ATTACHMENT (Table omitted.) |
|
ID: nht94-4.53OpenTYPE: INTERPRETATION-NHTSA DATE: October 14, 1994 FROM: Randal Busick -- President, Vehicle Science Corporation TO: Mary Versailles, Esq. -- Office of the Chief Counsel, NHTSA TITLE: Re: Request for interpretation of FMVSS 208 S7.1.2 ATTACHMT: Attached to 1/5/95 letter from Philip R. Recht to Randal Busick (A43; Std. 208; Std. 210) TEXT: Dear Ms Versailles: This is to request a clarification of FMVSS 208 S7.1.2. More specifically, would a seat belt system as shown on the attached drawing be in compliance with S7.1.2 as a so-called "semi-integrated" seat belt? As shown on the drawing, the inboard lower FMVSS 210 anchorage, n1 is located on the seat frame and thus, as the seat moves fore and aft, the system allows a minimum of two seat belt adjustment positions and the distance between the two extreme adjustmen t positions of the system is more than 5 cm. n1 The belt which holds the buckle is attached to this inboard anchorage. We look forward to your response. If you have any questions, kindly contact the undersigned. Sincerely Enclosure (Drawing omitted.) |
|
ID: nht95-4.75OpenTYPE: INTERPRETATION-NHTSA DATE: November 13, 1995 FROM: B. Michael Korte, Esq. -- Law Firm of John B. Schwabe II TO: NHTSA TITLE: Airbag Safety ATTACHMT: 1/29/96 letter from Samuel J. Dubbin to B. Michael Korte (A44; Std. 208) TEXT: To Whom It May Concern: I am a lawyer in St. Louis, Missouri who represents a client who injured in a rearend collision with another driver. The other driver's airbag deployed, but the other driver claims that she was travelling less than 15 miles per hour at impact. I have, as best as I can, reviewed 49 CFR 571.208 and other sections of the Code of Federal Regulations regarding federal standards as to the deployment of airbags. After doing so, however, I am unable to determine whether or not any federal standard s exist as to the deployment of airbags. In other words, I am unable to determine whether or not federal regulations establish a minimum speed that vehicles must be travelling, below which an airbag will not deploy. I would appreciate it if you would contact me and let me know whether or not any such regulations or guidelines exist. Thank you for your cooperation, courtesy and attention to this request. |
|
ID: 3235oOpen Mr. M. Iwase Dear Mr. Iwase: This is to provide you with a clarification of my letter to you dated March l6, l988. Your second question was whether the minimum edge to edge separation distance between turn signal lamps and tail/stop lamps is required on a rear lighting array for motorcycles. I responded that "The answer is yes, and the separation distance you have depicted in your drawings appears to comply with this requirement." In actuality, the agency has required this separation only where a single motorcycle stoplamp/taillamp is mounted on the vertical centerline, and not when dual lamps are mounted on either side of the vertical centerline, the configuration depicted in your letter of January 25, 1988. Therefore, I am advising you that there is no legal requirement that the 4-inch separation distance be maintained in the configurations you depicted, and that we appreciate your continuing efforts to understand and comply with Federal Motor Vehicle Safety Standard No. l08. I enclose a copy of a letter from this Office dated November 2l, l984, which explains our views on motorcycle rear lighting configurations in more detail. Sincerely,
Erika Z. Jones Chief Counsel Enclosure Ref:l08 d:l2/l/88 |
1970 |
ID: nht81-1.13OpenDATE: 02/11/81 FROM: AUTHOR UNAVAILABLE; F. Berndt; NHTSA TO: Toyoda Gosei Co., Ltd. TITLE: FMVSS INTERPRETATION TEXT:
Mr. Katsuhiko Yokoi Assistant Manager - Tech. Dept. Toyoda Gosei Co., Ltd. 1, Nagahata, Ochiai, Haruhi-mura Nishikasugai-gun Aichi-pref., 452 JAPAN Dear Mr. Yokoi: The answers to the questions in your letter of January 20, 1982, are "yes" to both questions. 1. The "adjacent layers" referenced in Federal Motor Vehicle Safety Standard (FMVSS) No. 106, paragraphs S7.3.7, are (a) the inner tube and braided layer and (b) the braided layer and outer tube. 2. The adhesion requirements are met if both the tensile strengths measured between (a) the inner tube and braided layer and (b) that between the braided layer and the outer cover are equal to or greater than 8 lbs/inch as determined using the FMVSS No. 106 procedure. It should be noted that the 8 lbs/inch value is an absolute minimum value as indicated in paragraph S8.6.4(a) standard. A copy of FMVSS No. 106 is included for your information. Sincerely, Vernon G. Bloom Safety Standards Engineer Enclosure FMVSS No. 106 |
|
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. |
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.