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: nht71-5.61OpenDATE: 09/15/71 FROM: AUTHOR UNAVAILABLE; C. A. Baker for E. T. Driver; NHTSA TO: E. R. Buske Mfg. Co., Inc. TITLE: FMVSS INTERPRETATION TEXT: Your letter of September 3, 1971, to the Bureau of Motor Carrier Safety concerning the mounting of lamps on a body backplate has been referred to this Office for consideration and reply. Federal Motor Vehicle Safety Standard No. 108 requires that lamps meet the applicable SAE Standards (including the photometric specifications) when tested as mounted on the vehicle. (See SAE J575c, Paragraph J.) The maximum angle from a line perpendicular to the longitudinal centerline of the vehicle that a lamp can be mounted and meet the applicable requirements depends upon the design and configuration of the lamp. We therefore recommend that you contact the manufacturer of your lamps for this maximum angle information. |
|
ID: nht90-4.26OpenTYPE: Interpretation-NHTSA DATE: September 28, 1990 FROM: Takahiro Maeda -- Assistant to the Vice President, Engineering Divison, Yamaha Motor Corporation, U.S.A.; Signature by Michael Schmitt TO: Office of Chief Counsel, NHTSA TITLE: Re FMVSS 108 ATTACHMT: Attached to letter dated 12-7-90 to T. Maeda from P.J. Rice (A36; Std. 108) TEXT: The purpose of this correspondence is to obtain your interpretation of minimum "edge to edge" separation between the tail/stop lamp and turn signals pursuant to FMVSS 108 Table IV. Tail/stop lamp design may feature a housing whereby the bulb reflector subassembly does not extend outward to the edge of the entire assembly. Can "edge to edge" be construed as the edge of the bulb reflector or is it necessarily the outer edge of the en tire tail/stop lamp assembly. Please refer to the attached illustration. We thank you for your insight into this question. Attached illustration. (Graphics omitted) |
|
ID: nht89-1.96OpenTYPE: INTERPRETATION-NHTSA DATE: 06/06/89 FROM: MICHAEL F. TRENTACOSTE -- DIRECTOR, OFFICE OF MOTOR CARRIER STANDARDS TO: STEPHEN P. WOOD -- ACTING CHIEF COUNSEL, NHTSA TITLE: REQUEST FOR INTERPRETATION OF FHWA AND NHTSA REGULATIONS ATTACHMT: ATTACHED TO LETTER DATED 06/19/89 FROM STEPHEN P. WOOD -- NHTSA TO GARRY O. MCCABE; REDBOOK A33 (2); STANDARD 301 LETTER DATED 01/25/89 FROM GARY O. MCCABE TO MIKE TRENTACOSTE TEXT: On February 27, 1989, you provided Mr. Ralph Hitchcock of NHTSA's Office of Vehicle Safety Standards a letter and drawings from Mr. Garry McCabe asking for information on a testing program for a "rapid fueling system" for trucks. Our response to Mr. McC abe discusses how NHTSA's regulations and motor vehicle safety standards may affect his product. Having reviewed the materials you forwarded to us, we are returning the letter and drawings to you. Please note that our response to Mr. McCabe addresses NHTSA's regulations only, and does not seek to interpret the applicable FHWA requirements. Attachment |
|
ID: nht93-7.14OpenDATE: October 7, 1993 FROM: John Womack -- Acting Chief Counsel, NHTSA TO: Erika Z. Jones -- Esq., Mayer, Brown & Platt TITLE: None ATTACHMT: Attached to letter dated 8/17/93 from Erika Jones to John Womack (OCC-9017) TEXT: This responds to your request for an interpretation of Federal Motor Vehicle Safety Standard No. 213, Child restraint systems. S5.2.3.2(b) of Standard No. 213 specifies a minimum thickness for materials of a certain compression-deflection resistance. You ask whether more than one piece of material may be used to meet the thickness requirement. The answer is yes. S5.2.3.2(b) does not require the material to be of a single piece, and the final rule that incorporated the requirement into Standard No. 213 did not address the issue. 44 FR 72131, December 13, 1979. Accordingly, more than one piece of material may be used. I hope this information is helpful. If you have any further questions, please contact us. |
|
ID: 9017Open Erika Z. Jones, Esq. Dear Ms. Jones: This responds to your request for an interpretation of Federal Motor Vehicle Safety Standard No. 213, Child restraint systems. S5.2.3.2(b) of Standard No. 213 specifies a minimum thickness for materials of a certain compression-deflection resistance. You ask whether more than one piece of material may be used to meet the thickness requirement. The answer is yes. S5.2.3.2(b) does not require the material to be of a single piece, and the final rule that incorporated the requirement into Standard No. 213 did not address the issue. 44 FR 72131, December 13, 1979. Accordingly, more than one piece of material may be used. I hope this information is helpful. If you have any further questions, please contact us. Sincerely,
John Womack Acting Chief Counsel ref:213 d:10/7/93 |
1993 |
ID: 86-2.5OpenTYPE: INTERPRETATION-NHTSA DATE: 03/04/86 FROM: GEORGE W. KEELEY -- HALFPENNY, HAHN & ROCHE TO: DIANE K. STEED -- ADMINISTRATOR U.S. DEPARTMENT OF TRANSPORTATION NATIONAL HIGHWAY TRAFFIC SAFETY ADMINISTRATION TITLE: NONE ATTACHMT: ATTACHED TO LETTER DATED 07/25/86 EST, TO GEORGE W KEELEY FROM ERIKA Z. JONES, REDBOOK A29(3), VSA 102; LETTER DATED 02/25/86 EST, TO RICHARD F HAHN FROM DIANE K STEED TEXT: Dear Ms. Steed: Thank you for your reply of February 25, 1986 to Mr. Hahn's letter to Secretary Dole on behalf of the Construction Industry Manufacturers Association. From your letter it is my understanding that the "interpretation letter" at issue does not constitute an NHTSA advisory opinion, nor does it have any legal precedential force or value. If my understanding is incorrect please advise. I would like to receive copies of correspondence and other documents if an advisory opinion is requested by, or issued to, Mr. Pennells, Pilington Glass Limited on this issue. Very truly yours, |
|
ID: nht94-3.5OpenTYPE: INTERPRETATION-NHTSA DATE: May 24, 1994 FROM: Carmen Colet -- Vice President, John Russo Industrial, Inc. TO: Dorothy Nakama, NHTSA TITLE: NONE ATTACHMT: Attached to letter dated 7/11/94 from John Womack to Carmen Colet (A42; VSA 102(3)) TEXT: WE ARE CONSTRUCTING AN AIRCRAFT RESCUE AND FIRE-FIGHTING VEHICLE TO SATISFY PROPOSED U.S.A.F. AND D.O.D. SPECS. FOR NEW TYPE YF AND YZ AIRCRAFT. 1. WE UNDERSTAND THAT FMVSS DOES NOT COVER THIS VEHICLE WHICH IS NOT PRIMARILY INTENDED FOR PUBLIC HIGHWAY USE. IT IS MADE TO OPERATE ON AIR FIELDS. ITS TIRES ARE 54" HIGH AND OVER 2 FT. WIDE AND MADE TO RUN FOR 20 MINUTES AR 65 MPH AS A GUIDELINE. T HE SMALL VEHICLE WEIGHS 20 TONS FULL OF WATER AND FOAM. BUMPERS ARE SPECIFIED AT 5 FT. HIGH. COCKPIT IS SIMILAR TO 117A STEALTH FIGHTER. IT CARRIES A POWER WATER TURRET ON TOP. ENCLOSED IS A CONFIDENTIAL PICTURE. 2. DO WE NEED TO USE THE 17 DIGIT FORMULA? 3. DO WE HAVE TO NOTIFY NHTSA SINCE THE VEHICLE IS NOT COVERED? |
|
ID: nht94-1.21OpenTYPE: INTERPRETATION-NHTSA DATE: January 19, 1994 FROM: Donald F. Lett -- Lett Electronics Co. TO: Department of Transportation -- NHTSA TITLE: None ATTACHMT: Attached To Letter Dated 5/18/94 From John Womack To Donald Lett (A42; Std. 109; Std. 110; Part 575.104) TEXT: Dear Sir, I was directed to your department by Mr. Duane Perrin to resolve any legal responsibility, if any, for the following question; Is there any pre-necessary authorization needed to modify an existing passenger tire, for instance a 215-70-R15 blackwall radial tire? Proposed Modification Grind down the existing sidewall 1/8 to 3/16 inch deep by 2 1/2" wide. Then vulcanizing white rubber into this recess making a 2 1/2" whitewall radial tire out of a previously D.O.T. approved radial blackwall tire. Thereupon we would merchandise this tire Nation wide to a specific classic car buff of the 1955-1960 era. Your kind attention to this matter would be greatly appreciate. Thank you, |
|
ID: nht91-4.15OpenDATE: June 5, 1991 FROM: Steven M. Healy; Morris G. Healy TO: Richard Van Eiderstein -- NHTSA TITLE: None ATTACHMT: Attached to letter dated 7-8-91 from Paul Jackson Rice to Steven M. Healy and Morris G. Healy (A38; Std. 108; VSA (a)(2)(A)) TEXT: Enclosed please find a brief description and drawing relative to monitoring lights that attach to bug deflectors (or shield) and/or to other appropriate mounting areas on vehicles. The primary purpose of these lights is to bring indicator lights up and into the line of vision of the vehicle operator. Mainly, directional signals and high beam indicator (or other appropriate applications desired by the operator). The need of focusing and refocusing the eyes is eliminated through their use. The existing indicator lights on the dash board are left undisturbed. A patent pending was obtained approximately two months ago. An opinion from your agency relative to the legality would be appreciated.
Attached to drawing of directional signal attached to bug deflector. (graphics omitted) |
|
ID: 2836oOpen Robert L. Bernard Dear Mr. Bernard: This letter responds to your inquiry of August 21, 1987, where you asked for this agency's opinion on whether Federal motor vehicle safety standard 115 (49 CFR 571.115) requires a manufacturer's chrome script name on the trunk of vehicles it manufactures. It does not. Standard 115, Vehicle Identification Number- Basic Requirements, directs a vehicle manufacturer to place a discrete vehicle identification number (VIN) on each vehicle it manufactures. Under paragraph S4.5, the VIN for any motor vehicle must appear indelibly on a part of the vehicle other than the glazing, that is not designed to be removed except for repair. Paragraph S4.6 states that the VIN for passenger cars must appear inside the passenger compartment. Title 49 CFR Part 565, VIN-Content Requirements, states that among other things, the VIN's first three characters must identify the vehicle manufacturer. However, neither Standard 115 nor Part 565 require a manufacturer's name plate to appear on the vehicle. I hope you find this information helpful. Sincerely,
Erika Z. Jones Chief Counsel ref:115#115 d:3/7/88 |
1988 |
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.