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 |
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ID: nht92-2.27OpenDATE: November 16, 1992 FROM: Terry W. Wagar -- Technical Services Bureau, State of New York, Department of Motor Vehicles, Division of Vehicle Safety Services TO: Paul Jackson Rice -- Chief Council, NHTSA TITLE: None ATTACHMT: Attached to letter dated 1/22/93 from John Womack to Terry Wagar (A40; Std. 205) TEXT: I am writing to you regarding the repair of automotive safety glazing. I would like to know what the NHTSA's legal position is on the repair of glazing on in service motor vehicles that were originally designed to comply with FMVSS 571.205. The company "Ultra B-0-N-D, Inc.", 11151 Pierce Street, Riverside, CA 92505 (1-800-347-2820) requests that the New York State Department of Motor Vehicles establish that windshield glazing repair be accepted and repaired glass meet New York State inspection criteria. The Ultra B-0-N-D repair process is applied to line cracks small bruises and star cracks. Equipment is attached to the glass with suction cups to open the crack. A liquid is injected through the entire crack. Equipment is removed. A lamp is used to cure the chemical. Finally the repaired area is scraped with a razor blade then cleaned with window cleaner. When repaired, the crack is "not as visible". Please guide us with your agencies opinion in this matter. If you have any questions, you may reach me at (518) 474-5176. |
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ID: nht74-4.29OpenDATE: 06/19/74 FROM: AUTHOR UNAVAILABLE; L. R. Schneider; NHTSA TO: Busby, Rivkin, Sherman, Levy, and Rehm COPYEE: DYSON; DUGOFF; CARTER TITLE: FMVSS INTERPRETATION TEXT: This is in response to your letter of June 10, 1974, in which you asked for our interpretation of the preemption provisions of the National Traffic and Motor Vehicle Safety Act (sec. 103(d)) with respect to the Pennsylvania position on brake hose. A letter that you enclosed from the Pennsylvania Department of Transportation advised a manufacturer's representative that "Pennsylvania will continue to approve brake hoses under the SAK Standards for air, hydraulic and vacuum hose," and that the State "will continue to require the hose be identified in the same manner as our present regulations," with the Federally-required labeling placed on "a separate line" from the State's labeling. Section 103(d) of the Act, 43 U.S.C. 1392(d), plainly prohibits any State from establishing or continuing in effect a safety standard applicable to an item of motor vehicle equipment, where there is an applicable Federal standard, unless the State standard is "identical to the Federal standard." This preemption provision takes effect wherever a Federal standard is applicable to the same aspect of performance as the State standard. When the new Federal standard on brake hoses comes into effect, with its testing and labeling requirements, any differing State standards, as Pennsylvania's appear to be, will be preempted and void. |
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ID: nht73-1.1OpenDATE: 02/20/73 FROM: AUTHOR UNAVAILABLE; L. R. Schneider; NHTSA TO: Joe Motley TITLE: FMVSS INTERPRETATION TEXT: March 28, 1973 Mr. Joe Motley 2704 Sparkman Drive, N. W. Huntsville, Alabama 35810 Dear Mr. Motley: This is in reply to your letter of December 15, 1972, regarding requirements applicable to manufacturers of ambulances. Ambulances are considered by NHTSA to be "multipurpose passenger vehicles", a vehicle type to which several Federal motor vehicle safety standards and regulations are applicable. Manufacturers of ambulances, including those who convert other vehicle types to ambulances, are required to manufacture each ambulance in accordance with those standards and regulations applicable to multipurpose passenger vehicles. The enclosed leaflet contains a short list and description of the standards and regulations, indicating which vehicle types are subject to each standard. The NHTSA is reponsible for both the promulgation and the enforcement of these standards. We rely on persons such as yourself to report possible violations of our requirements, and we appreciate your writing to us. I have referred your letter to our Office of Standards Enforcement, which will take steps to see that vehicles are manufactured in accordance with the Federal motor vehicle safety standards and other NHTSA regulations. Sincerely, Lawrence R. Schneider Chief Counsel |
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ID: nht73-1.15OpenDATE: 06/26/73 FROM: AUTHOR UNAVAILABLE; R. B. Dyson; NHTSA TO: Trelleborgs Gummifabriks Aktiebolag TITLE: FMVSS INTERPRETATION TEXT: This is in reply to your letter of May 28, 1973, asking whether you may, consistently with Federal Motor Vehicle Safety Standard No. 109, label maximum load and maximum permissible inflation pressure as follows, using the 165 SR 15 tire size designation as an example: 1. Max Load 1200 Lbs. At 36 psi 2. Max Load 1200 Lbs. At Max Press 36 psi We do not believe alternative 1 to be consistent with Standard No. 109 because it is not clear that 36 psi is the maximum permissible inflation pressure. Alternative 2 does so indicate, however, and we believe that alternative to be consistent with the standard. Yours truly, Secretary of Transportation National Highway Safety Bureau, US Department of Transportation May 28, 1973 MVSS 109 Dear Sirs; Please inform us if we are allowed to use this alternative labelling on our tires, i.e. on tire size 165 SR 15: Alternative 1: "Max Load 1200 Lbs AT 36 psi" Alternative 2: "Max Load 1200 Lbs At Max Press 36 psi" Yours sincerely, TRELLEBORGS GUMMIFABRIKS AKTIEBOLAG Tire Research -- Erik Sundelin |
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ID: nht73-1.45OpenDATE: 02/05/73 FROM: AUTHOR UNAVAILABLE; Robert L. Carter; NHTSA TO: Mr. Harvey E. Schock, Jr. TITLE: FMVSS INTERPRETATION TEXT: Thank you for your memo of January 18, 1973, concerning glazing materials. I am enclosing a copy of Federal Motor Vehicle Safety Standard No. 205,Glazing Materials. Certification of conformance to Standard No. 205 is self-certification. No approval by the Federal Government is required. If you are not aware of State approvals, you may want to contact Mr. Armand Cardarelli of the American Association of Motor Vehicle Administrators, Suite 500, 1828 L Street, N.W., Washington, D.C. 20036. If I can be of further service, please do not hesitate to ask. Sincerely, Enclosure No Control M E M O FROM: Harvey E. Schock, Jr. To The Associate Administrator Motor Vehicle Programs National Highway Safety Administration January 18, 1973. RE:FR Docket 73-644 Prime Glazing Material Manufacturer Codes Gentlemen: I would appreciate information on the requirements and procedures for the certifying that glazing materials conform to Motor Vehicle Safety Standard No 205 "Glazing Materials" I would appreciate a copy of the Standard and any additional information on this subject. Thank you for your cooperation. |
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ID: nht73-2.9OpenDATE: 09/10/73 FROM: Richard B. Dyson; NHTSA TO: Cannon's Cycle Center Inc. TITLE: FMVSS INTERPRETATION TEXT: Robert Aubuchon of this agency has asked us to respond to our recent inquiry whether the Solex motor bicycle is a "motor vehicle" under our regulations, and, if so, how we would categorize it. You are also interested in knowing how our views affect South Carolina's proposed redefinition of bicycle. Since the Solex is manufactured primarily for use on the public roads, it is a "motor vehicle" as defined by the National Traffic and Motor Vehicle Safety Act of 1966, specifically a "motorcycle". As such, it must meet all Federal motor vehicle safety standards applicable to "motorcycles", and be so certified by its manufacturer. The only such standard currently in effect is No. 108, Lamps, Reflective Devices and Associated Equipment, but standards on controls (No. 122) and braking (No. 123) will become effective January 1, 1974 and September 1, 1974 respectively. While the proposed South Carolina redefinition of "bicycle" appears to encompass the Solex, the State by so doing could neither relieve the manufacturer from the obligation of complying with Federal motorcycle safety standards, nor impose requirements different from Standards Nos. 108, 122, and 123 as to those aspects of performance covered by the Federal standards. I hope this answers your questions. |
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ID: nht73-3.21OpenDATE: 02/07/73 FROM: AUTHOR UNAVAILABLE; Richard B. Dyson; NHTSA TO: Mr. Satoshi Nishibori TITLE: FMVSS INTERPRETATION TEXT: This is in reply to your letters of December 15, 1972, and January 3, 1973, concerning paragraph S7.4.3 of Standard 208. As I understand the question, you are positing a situation in which the occupants have correctly operated their belts, thereby permitting the engine starting system to operate, but in which the cranking of the engine by the starter motor does not start the engine and the key is returned to the "on" position. Your question is whether the ignition can thereafter be turned from "on" to "start" in repeated efforts to start the engine, without interference from the interlock. Our reply is that S7.4.3 permits a system in which the initial correct operation of the belts, followed by operation of the starting system, places the system in a "free-start" mode so long as the ignition is not turned to "off". Repeated efforts to start the engine would therefore be permitted, regardless of the status of the belts. If the ignition has been turned off and if the system is not in another of the "free-start" modes allowed by S7.4.3, then the engine starting system will not be operable with an unbelted driver on the seat unless an engine compartment switch is operated pursuant to S7.4.4. |
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ID: 77-5.21OpenTYPE: INTERPRETATION-NHTSA DATE: 12/30/77 FROM: AUTHOR UNAVAILABLE; J. J. Levin, Jr.; NHTSA TO: W. G. Milby TITLE: FMVSS INTERPRETATION TEXT: This responds to your November 14, 1977, letter asking about the applicability of the requirements of Standard 217, Bus Window Retention and Release, to roof exits which use lexan or other glazing materials as part of their structure. You first ask whether these exits would be required to comply with the standard's window retention test. Section S5.1 of the standard requires that each piece of window glazing and each surrounding window frame comply with the requirements of the window retention test. Since the lexan to which you refer is glazing material, a structure using such material would be required to comply with the window retention test. In a second question, you ask whether this type of exit can employ a release mechanism that consists of a gasket filler strip. This gasket releases the exit when pulled, by a single force, in a direction perpendicular to the exit. Since the application of force required to release the exit is in the proper direction as established by S5.3.2 of the standard, the exit would appear to comply with the exit release requirements as long as the release mechanism is within the correct force application zone and requires the proper amount of energy to effect its release.
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ID: nht76-1.10OpenDATE: 06/29/76 FROM: AUTHOR UNAVAILABLE; J. Womack for F. Berndt; NHTSA TO: General Motors Corporation COPYEE: GEORGE NIELD -- AUTOMOBILE IMPORTERS ASSOC. TITLE: FMVSS INTERPRETATION TEXT: This responds to General Motors Corporation's May 27, 1976, petition to commence rulemaking to amend Standard No. 105-75, Hydraulic Brake Systems, in order to return one sentence to the text of S5.1.5.2(a) that was omitted in a September 17, 1975, revision of that section (40 FR 42872). The sentence reads: "However, the maximum control force for the fifth stop in the case of a vehicle manufactured before September 1, 1976, shall be not more than plus 60 pounds of the average control force for the baseline check (but in no case more than 110 pounds)." The National Highway Traffic Safety Administration considers a petition to amend the standard to be unnecessary because the omission was inadvertent and did not constitute a substantive change to the requirements of the standard. Therefore, an interpretative amendment to conform the language to that intended will be forthcoming in the near future. Interested persons are notified that the interim control force value has been in effect for all vehicles of 10,000 pounds gross vehicle weight rating or less despite the omission of the sentence on September 17, 1975. Thank you for bringing this omission to the attention of the agency. |
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ID: nht75-1.50OpenDATE: 11/18/75 FROM: AUTHOR UNAVAILABLE; R. B. Dyson; NHTSA TO: Tong Shin Chemical Products Co., Ltd. TITLE: FMVSS INTERPRETATION TEXT: This is in response to your inquiry concerning the addition of the symbol "DOT" to tires imported into this country, and in confirmation of your telephone conversation with Mr. Schwartz of this office. 49 CFR Part 574, Tire Identification and Recordkeeping, requires tire manufacturers to permanently mold into or onto the sidewall of tires an identification number and the symbol DOT. The position of the identification number and DOT symbol is illustrated in Figures 1 and 2 of the Regulation. The symbol DOT, as stated in Motor Vehicle Safety Standard No. 109, New Pneumatic Tires, 49 CFR 571.109, constitutes a certification that the tire conforms to all applicable safety standards. Neither Standard No. 109 nor Part 574 prohibit the branding of the symbol DOT onto the tire after manufacture, as long as the information becomes part of the actual sidewall material. By branding the symbol DOT onto the tire you are certifying that the tires meet all the requirements of the motor vehicle safety standards based on information which, in the exercise of due care, you know to be accurate. If you have further questions concerning this matter, please do not hesitate to contact me. |
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.