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: nht92-5.14OpenDATE: July 22, 1992 FROM: Arye Addady -- Maaco TO: U.S. Department of Transportation -- NHTSA TITLE: None ATTACHMT: Attached to letter dated 9/11/92 from Paul Jackson Rice to Arye Addady (A39; Std. 105) TEXT: I am working on an idea (patent pending) that will require installation of a device to the hydraulic brake system of a vehicle, (this will not reduce or alter in any way the integrity of the brakes) and I would like to know if a permission from your department is required. (I am aware, however, that in any event as the alteree I am ultimately responsible for anything that may happen due to the alteration.) Would you be kind to advise me if a permission is required. Thank you very much for your swift reply. |
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ID: nht92-7.48OpenDATE: April 6, 1992 FROM: Gonshiro Miyoshi -- Manager, Design Administration Dept., Technical Division Ichikoh Industries, Ltd. TO: Paul Jackson Rice -- Chief Counsel, NHTSA TITLE: Our Reference LO4-11 ATTACHMT: Attached to letter dated 5/8/92 from Paul J. Rice to Gonshiro Miyoshi (A39; Std. 108) TEXT: This letter is in regards to the interpretation of headlamp arrangement in FMVSS No. 108. We would like to know your opinion regarding the below mentioned arrangement of headlamp system consisting of two lamps, each containing two light sources. Is it permissible to have the bulb center of the lower beam lower than that of the upper beam (maximum height difference is 10mm) if they are arranged horizontally? Kindly let us know your opinion concerning the above matter. |
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ID: nht92-6.36OpenDATE: May 26, 1992 FROM: Joe Wos -- A & D Lock & Key TO: Office of Chief Council Nat. Highway Traffic Safety Add. TITLE: None ATTACHMT: Attached to letter dated 6/24/92 from Paul J. Rice to Joe Wos (A39; Std. 208); Also attached to letter dated 1/19/90 from Stephen P. Wood to Linda L. Conrad (Std. 208) TEXT: I am a locksmith. I am in the business of rebuilding steering columns that have been damaged during collisions. I have one question I need an answer to. Is it legal to repair an automobile that has had an air bag deployed and not put the air bag back in. In other words can you put a non air bag type steering column into a car that originally had an air bag? Looking forward to your answer. |
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ID: nht94-3.39OpenTYPE: INTERPRETATION-NHTSA DATE: June 16, 1994 FROM: DOUG BEREUTER -- Member of Congress, House of Representatives TO: Christopher Hart -- Acting Administrator, NHTSA TITLE: NONE ATTACHMT: Attached to Letter Dated 09/16/94 from Christopher A. Hart (for Ricardo Martinez) to Doug Bereuter (A42; Part 303) TEXT: I am writing to you again regarding my continuing interest in the National Highway Traffic Safety Administration's (NHTSA) long-delayed rulemaking concerning compressed natural gas fuel containers. In previous correspondence, you stated that the final r ule would be sent to the Office of Management and Budget for review. Has this happened or is this no longer necessary? Please send me an update on the current status of the rulemaking. Despite past assurances, this matter continues to be stalled. I w ant evidence that progress is being made. This matter is too important to be placed on NHTSA's back-burner. |
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ID: nht93-6.30OpenDATE: September 2, 1993 FROM: John M. Tolliday -- President, Dayman USA, Inc. TO: John Womack -- Acting Chief Counsel, N.A.H.T.S.A. (NHTSA) TITLE: None ATTACHMT: Attached to letter dated 3/16/94 from John Womack to John M. Tolliday (A42; Part 591 Sec 102(3); Also attached to letter dated 8/7/89 from Stephen P. Wood to Clifford Anglewicz (Sec 102) TEXT: We are hoping to import into the United States British Army Ferret Armored Cars of which I enclose two photos. These vehicles were manufactured around 1970. They are in a driveable condition, but all armaments have been removed. I would be selling these on the basis they would only be used for off road purposes. If we did import these vehicles would they be exempt from Federal Motor Vehicle Standards? Thanking you in advance for your assistance. |
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ID: nht75-1.42OpenDATE: 07/14/75 FROM: AUTHOR UNAVAILABLE; J. C. Schultz; NHTSA TO: Hendrickson Mfg. Company TITLE: FMVSS INTERPRETATION TEXT: Please forgive the delay in responding to your letter of March 26, 1975, requesting an interpretation of the masking requirements of Federal Motor Vehicle Safety Standard No. 106-74, Brake Hoses. The requirement that the label on a brake hose remain visible after painting was amended on March 17, 1975, (40 FR 12088, Docket No. 1-5, Notice 16) to permit the label to remain masked if (1) the masking material is affixed in such a way that no adhesive contacts any part of the label and (2) the masking is manually removable. Since the requirement that the label be masked or visible, rather than obscured, is a vehicle requirement, it is not effective until September 1, 1975. Vehicles manufactured before that date may contain hose which has been painted over. |
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ID: nht95-3.7OpenTYPE: INTERPRETATION-NHTSA DATE: June 8, 1995 FROM: David A. Lowell -- Engineering Manager, Bankhead Enterprises, Inc. TO: Chief Counsel, NHTSA TITLE: NONE ATTACHMT: ATTACHED TO 7/25/95 LETTER FROM JOHN WOMACK TO DAVID A. LOWELL (REDBOOK 2; STD. 108) TEXT: Dear Chief Counsel, Bankhead Transportation Equipment designs and manufactures stinger steered automobile transport trailers as defined in 23 CFR Part 658.5 K, M, N. As shown in the enclosed pictures we currently place tail, turn and clearance lights on the back of our truck-tractor. Per 49 CFR Part 571.108 S5.1.1.1 and S5.1.1.2 these items do not seem to be necessary. We are considering removing these lights but realize we have a specialized unit. Please confirm the legality of the necessity of tail, turn and clearance lights on the back of our truck-tractor. Enclosures (photos) omitted. |
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ID: nht89-1.78OpenTYPE: INTERPRETATION-NHTSA DATE: 04/20/89 FROM: GAY M. ARTHUR TO: TAYLOR VINSON -- NHTSA OFFICE OF CHIEF COUNCIL TITLE: NONE ATTACHMT: ATTACHED TO LETTER DATED 07/24/89 FROM STEPHEN P. WOOD -- NHTSA TO GAY M. ARTHUR; REDBOOK A33 [2]; STANDARD 108 TEXT: Dear Mr. Vinson, I am requesting clarification on the restrictions (if any) for the exterior roof on passenger cars. More specifically, I'd like to know if detachable, lighted novelty items are legally allowable on passenger cars. In addition, if your office knows of specific restrictions by state, i.e., size or color, lighted or not, etc., I would also appreciate that information as well. If there is any cost for the photocopies, please let me know and I would be happy to send i t to you. Enclosed you will find a self-addressed stamped envelope for your use. Thank you for your time and consideration in this matter, and for your prompt reply. Sincerely, |
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ID: nht89-2.56OpenTYPE: INTERPRETATION-NHTSA DATE: AUGUST 3, 1989 FROM: W. MARSHALL RICKERT -- ADMINISTRATOR, MARYLAND DEPT. OF TRANSPORTATION TO: TRACEY POWELL -- LEGISLATIVE COORDINATOR, GOVERNMENT RELATIONS, AMERICAN MOTORCYCLIST ASSOCIATION TITLE: NONE ATTACHMT: ATTACHED TO LETTER DATED 11-14-89 TO STEPHEN P. WOOD FROM TRACEY POWELL; [OCC-4154] TEXT: Secretary Trainor has asked me to respond to your July 24 letter concerning modulating headlights. In Maryland, the use of a modulating headlight on a motorcycle is not permitted. By law, "flashing lights" are reserved strictly for emergency vehicles. When the National Highway Traffic Safety Administration approved the use of this type of light, we did consider allowing the use of the modulating light. However, there was a great deal of concern that the "flashing lights" on motorcycles would be confusing to other motorists. Based on this, no changes were made. After you complete your tabulation on States allowing the modulatory light, please send me a copy. This information could be very useful if we again consider making a change. In the meantime, if I can be of further assistance, please contact me. |
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ID: nht74-2.49OpenDATE: MAY 24, 1974 FROM: ALFRED TEVES TO: JAMES B. GREGORY -- ADMINISTRATOR-NHTSA TITLE: INTERPRETATION OF FMVSS NO. 105-75 ATTACHMT: OCTOBER 3, 1988 LETTER FROM JONES TO BURKARD, EBNER, AND TEVES, FEBRUARY 3, 1981 LETTER FROM KAWANO TO BERNDT, JULY 10, 1974 LETTER FROM DYSON TO NAKAJIMA, MAY 27, 1988 LETTER FROM TEVES TO JONES, AND OCTOBER 9, 1988 LETTER FROM JONES TO BURKARD, EBNER, AND TEVES TEXT: We wish to request clarification of our interpretation of S5.4.1, Master Cylinder Reservoirs, of FMVSS No. 105-75, (105a) published in the Federal Register on May 18, 1973. S.5.4.1 reads as follows: Master Cylinder Reservoirs. A master cylinder shall have a reservoir compartment for each service brake subsystem serviced by the master cylinder. Loss of fluid from one compartment shall not result in a complete loss of brake fluid from another compartment. As we understand it, this Section does not prohibit the designs sketched below. See Illustration on Original F: Front R: Rear C: Clutch |
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.