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: 20294.drnOpenLance Tunick, Esq. Dear Mr. Tunick: This responds to your request for an interpretation of Standard No. 104, Windshield wiping and washing systems. Specifically, you wish to know whether Standard No. 104 has incorporated by reference the durability requirements of SAE Recommended Practice J903a, "Passenger Car Windshield Wiper Systems," May 1966. The answer is no. In Standard No. 104, the National Highway Traffic Safety Administration has selectively incorporated by reference the following provisions of SAE Recommended Practice J903a, May 1966: The "glazing surface reference line" shown in Figure 1; the "plan view reference line" shown in Figure 2; conditions for the test procedures of the frequency and speed of the windshield wiping system (See S4.1.1.4 of Standard No. 104); wet test procedures in determining percentages of areas of the windshield that are wiped (S4.1.2 of Standard No. 104); and establishing areas A, B, and C of the windshield (See S4.1.2.1 of Standard No. 104). None of these incorporated provisions relate to any durability requirements specified in SAE Recommended Practice J903a, May 1966. I hope this information is helpful. If you have any further questions, please contact Dorothy Nakama of my staff at (202) 366-2992. Sincerely, |
1999 |
ID: nht93-3.43Open
DATE: May 13, 1993 EST FROM: Shawn Shieh -- Ventures International USA TO: Office Enforcement -- NHTSA TITLE: None ATTACHMT: Attached to letter dated 6-8-93 from John Womack to Shawn Shieh (A41; Std. 108); Also attached to letter dated 8-17-89 from Stephen P. Wood to Alan S. Eldahr (Std. 108) TEXT: My name if Shau Shieh. My company has a patent pending emergency communication product. It is intended for use inside automobils. It is needs to be mounted in the back window of an automobile permanently. I would like to find out what are the restrictions and specifications I have to follow. The product uses Light Emitting Diodes to form any emergency messages and intend from drivers from behind to read. It is to promote safe driving and to call for speedy help. I know it cannot be read or yellow in color. But I am not sure what is the maximum size of a permanent structure to be installed in an automobil. What about the matterial of the base support and wiring restrictions. Can you please help me? Where can I find these information: What other government agency I have to go through? Are these information available in local central library? I hope to hear from soon. Thank you very much? |
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ID: nht69-1.34OpenDATE: 03/12/69 FROM: AUTHOR UNAVAILABLE; R. M. O'Mahoney; NHTSA TO: Hector J. Rosso, Esq. TITLE: FMVSS INTERPRETATION TEXT: This is in response to your letter of February 14, 1969, in which you seek information concerning possible overloading of Seiberling 8.25-20 ten ply rating truck tires manufactured in approximately 1963. The Federal Highway Administration has issued a Federal motor vehicle safety standard for passenger car tires manufactured after January 1, 1968 requiring them to meet certain tests when loaded to prescribed weights. (49 C.F.R. @ 371.21 Standard 109). Performance requirements for truck tires are presently under consideration. Comments have been received in response to an Advance Notice of Proposed Rule Making on this matter but regulations have not as yet been issued. The Bureau of Motor Carrier Safety regulates the safety and operation of interstate motor carriers. Its regulation regarding tires (49 C.F.R. @ 393.75) is not relevant to your inquiry. One fruitful source of information may be the Tire and Rim Association Yearbook. This publication provides data on tires and suggests standards for tire load limits. It is published by the Tire and Rim Association, Inc., Comend Building, 34 H. Hawkins Avenue, Akron, Ohio 44313. I hope this information will be of value to you. |
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ID: nht70-1.12OpenDATE: 10/29/70 FROM: AUTHOR UNAVAILABLE; R. H. Compton; NHTSA TO: Atlas Supply Company TITLE: FMVSS INTERPRETATION TEXT: Reference is made to your letter of October 8, 1970, requesting an increase in the maximum permissable overall width of the "78" series belted bias passenger car tires covered by Table I-J, Appendix A, of MVSS 109. The dimensional requirements specified in MVSS 109 for passenger car tires are the result of a rule making action in which the tire industry and other interested persons participated. Tire section width and overall width were permitted to exceed the specified section width dimensions by 7% to accommodate differences in manufacturing tolerances, design practice, tire growth patterns when inflated, and to provide for sidewall decorations and protective ribs. The allowance of 7% is considered the maximum desirable for dimensional uniformity and interchangeability among tires of the same size produced by different manufacturers. For this reason, we cannot give favourable consideration to your request at this time. |
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ID: nht88-2.17OpenTYPE: INTERPRETATION-NHTSA DATE: MAY 5, 1988 FROM: I. ROBERT EHRLICH -- ENGINEER TO: RICHARD STROMBOTNE -- NHTSA OFFICE OF SAFETY STANDARDS ATTACHMT: ATTACHED TO MEMO DATED 12-19-88, TO I. ROBERT EHRLICH, FROM ERIKA Z. JONES -- NHTSA, REDBOOK A33, PART 571.3, PART 567 TEXT: Would you please send me a copy of NHTSA Docket 88-06, Notice 1 and Docket 88-07, Notice 1 proposing to strengthen the side impact crash test procedures and performance requirement for passenger cars, as indicated in the attached clipping from Automotive Engineering, APRIL 1988. What I am particularly interested in is whether or not the proposed new standards will include stretch limousines, which are frequently covered by light sheet steel to fill in the gap created by lengthening a conventional passenger car. This leaves a wide, unprotected gap in the center. Side Impact Protection -- The January 27, 1988, Federal Register contained NHTSA Docket 88-06, Notice 1 (page 2239), and Docket 88-07, Notice 1 (page 2254), proposing to strengthen the side impact crash test procedures and performance requirements for pa ssenger cars, and specifying a new side impact test dummy. The amendments would require a test procedure to simulate a severe side crash, a barrier to represent a striking vehicle, a test dummy specially designed for side impacts, and maximum injury crit eria for the dummy. Ten percent of a manufacturer's production would be required to meet the standard during the first year, which would begin two years after publication of the final rule. The percentage would increase to 25% the next year, 40% the thi rd year and 100% thereafter. Comments on both Notices are due October 24, 1988. For further information contact Dr. Richard Strombotne, NHTSA Office of Vehicle Safety Standards (202) 366-4916. |
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ID: 86-4.12OpenTYPE: INTERPRETATION-NHTSA DATE: 07/11/86 FROM: ERIKA Z. JONES -- CHIEF COUNSEL NHTSA TO: FRANCISCO DEE TAN -- PRESIDENT FRG INDUSTRIAL CORPORATION TITLE: NONE TEXT: Dear Mr. Tan: This is in reply to your letter of April 15, 1986, asking for our approval of different types of rear stop lamps you wish to import. The lighting devices depicted in the brochures that you enclosed are not intended as original or replacement motor vehicle equipment, and therefore are not coverd by Federal Motor Vehicle Safety Standards No. 108, Lamps, Reflective Devices, and Associated Equipment. If you are required to execute a Form HS-7 at the time of entry, the proper declaration is that provided by Box 1: the equipment was manufactured on a date when no Federal standards applied to it. In any event, this agency has no authority to approve or disapprove items of motor vehicle equipment since the National Traffic and Motor Vehicle Safety Act provides for self-certification by manufacturers of their products subject to Federal standards. In the absence of Federal requirements, whether the devices you wish to import are legal for installation and use would be determinable under the laws of the individual States where the devices will be sold and installed. I hope that this answers your question. Sincerely |
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ID: nht91-7.19OpenDATE: November 26, 1991 FROM: H. Ino -- Manager, Quality Assurance, Diamond Star Motors TO: Paul Jackson Rice -- Office of Chief Counsel TITLE: NHTSA'S VIN Requirements (FMVSS 115) ATTACHMT: Attached to letter dated 2/11/92 from Paul Jackson Rice to H. Ino (A39; VSA 108(b)(3); Std. 115) TEXT: In a telephone conversation on Friday, Nov. 22nd, Ms. Dorothy Nakama informed Diamond-Star Motors that FMVSS 115 is only applicable to vehicles manufactured for sale in the United States. She also recommended that in order to receive this in writing I must send a written request for an interpretation of FMVSS 115. Please send an interpretation of FMVSS 115 which addresses to whom this standard is applicable and any exceptions that are applicable. Thank you very much. |
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ID: 86-4.20OpenTYPE: INTERPRETATION-NHTSA DATE: 07/23/86 EST FROM: ERIKA Z. JONES -- CHIEF COUNSEL NHTSA TO: FRANCISCO DEE TAN -- PRESIDENT FRG INDUSTRIAL CORPORATION TITLE: NONE ATTACHMT: LETTER DATED 04/15/86 RE HS7 FORM APPLICATION APPROVAL FOR REAR WINDOW 3RD STOP LIGHT, TO NHTSA FROM FRANCISCO DEETAN, OCC-0606 TEXT: Dear Mr. Tan: This is in reply to your letter of April 15, 1986, asking for our approval of different types of rear stop lamps you wish to import. The lighting devices depicted in the brochures that you enclosed are not intended as original or replacement motor vehicle equipment, and therefore are not covered by Federal Motor Vehicle Safety Standard No. 108, Lamps, Reflective Devices, and Associated Equipment. If you are required to execute a Form HS-7 at the time of entry, the proper declaration is that provided by Box 1: the equipment was manufactured on a date when no Federal standards applied to it. In any event, this agency has no authority to approve or disapprove items of motor vehicle equipment since the National Traffic and Motor Vehicle Safety Act provides for self-certification by manufacturers of their products subject to Federal standards. In the absence of Federal requirements, whether the devices you wish to import are legal for installation and use would be determinable under the laws of the individual States where the devices will be sold and installed. I hope that this answers your question. Sincerely, |
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ID: 11655DRNOpen Mr. Roger Wilk Dear Mr. Wilk: This responds to your letter asking for information on regulations Apertaining to the horn used as a warning device on an automobile.@ The National Highway Traffic Safety Administration (NHTSA) does not require a horn on motor vehicles. Our safety standard for motor vehicle controls and displays (Safety Standard No. 101, 49 CFR '571.101) specifies requirements for a horn if one is provided. The horn must be operable by the driver, and must be identified as specified in the standard. I am enclosing a copy of Standard No. 101 for your information. Our sister agency in the Department, the Federal Highway Administration (FHWA), has operational and equipment requirements for commercial vehicles used in interstate commerce. For further information about FHWA requirements, you can contact that agency's Chief Counsel's office at (202) 366-0650. In addition, some States regulate the use of horns. You have provided an excerpt (Section 12-401 "Horns and other Warning Devices") from the Uniform Vehicle Code and Model Traffic Ordinance. The Code is not a Federal statute, but is available for enactment by the States. You may be able to determine whether Illinois or any other State has enacted Section 12-401 by contacting: Automotive Manufacturers Equipment Compliance Agency, Inc. 888 16th St., NW, Suite 700 Washington, DC 20006 Tel.: (202) 898-0145; FAX (202) 898-0148 I hope this information is helpful. If you have any further questions, please contact Dorothy Nakama of my staff at (202) 366-2992. Sincerely,
Samuel J. Dubbin Chief Counsel Enclosure ref:571#101 d:4/5/96
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1996 |
ID: nht74-5.8OpenDATE: 02/21/74 FROM: AUTHOR UNAVAILABLE; Richard B. Dyson; NHTSA TO: Bridges and Collins TITLE: FMVSR INTERPRETATION TEXT: In reply to your request of January 30, 1974, I am enclosing a copy of the regulation issued to implement the odometer disclosure requirements of Public Law 92.513. Although there are a variety of ways to determine whether a vehicle's actual mileage is greater than shown on the odometer, I know of only one method to establish the exact amount by which the indicated mileage has been exceeded: the testimony of a witness who knew the exact mileage on the car at the time the odometer was changed and who knows the accuracy of the odometer's performance after the change. I would be most interested to learn of the progress of your action. BRIDGES AND COLLINS January 30, 1974 Department of Transportation National Highway Traffic Safety Administration IN RE: Odometer Disclosure Requirements Dear Administrator: I am at the present time attempting to prosecute a civil action under Section 408 (a) of Title IV of the Motor Vehicle Information and Cost Savings Act (Public law 92-513). (This statute may be found in 15 U.S.C.A. @ 1988.) Please send me a copy of the current rules regulating this statute. I am having some difficulty determining the true mileage of the vehicle in question. If you know of a procedure for determining the actual mileage of a motor vehicle, please pass that information along to me. I would be most appreciative. I can use the above-requested information as quickly as you can supply it. Thank you for your prompt assistance and cooperation. James B. Steward |
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.