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: aiam3912OpenMr. Jim Preisler, Senior Vice President, Drag Specialties, P.O. Box 9336, Minneapolis, MN 55440; Mr. Jim Preisler Senior Vice President Drag Specialties P.O. Box 9336 Minneapolis MN 55440; Dear Mr. Preisler: This responds to your letter of January 17, 1985, concerning Standar No. 205, *Glazing Materials*. Your company manufactures an aftermarket replacement motorcycle windscreen, which incorporates auxiliary wind deflectors. Standard No. 205 specifies that the upper portion of the windshield can be made out of item 1, 6, 10, or 11 glazing materials. The glazing used in the auxiliary wind deflectors can be made out of item 1, 2, 4, 10, or 11A glazing materials. You said that the glazing material used in the windscreen and deflector meets the requirements for both item 4 and 6 glazing materials. You asked whether you can mark both those components as item 4/6 glazing materials. The answer is that you can mark them as item 4/6 materials.; Section S6 of the standard sets out the certification and markin requirements for each item of glazing material. It provides that each piece of glazing material shall be marked, in accordance with section 6 of American National Standard Safety Code for Safety Glazing Materials for Glazing Motor Vehicles Operating on Land Highways' Z-26.1 - 1977, January 26, 1977, as supplemented by Z26.1a, July 3, 1980, with a number signifying that it meets the performance requirement set for that particular glazing item number. In your case, the glazing material meets all of the requirements set for two separate item numbers. Since your product conforms to the requirements for both items 4 and 6 the agency has no objection to marking the components with both item numbers.; Sincerely, Jeffrey R. Miller, Chief Counsel |
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ID: aiam5306OpenMr. Andrew Tweddle AV Technology Corp. 2340 Alger Troy, MI 48083; Mr. Andrew Tweddle AV Technology Corp. 2340 Alger Troy MI 48083; Dear Mr. Tweddle: This responds to your request for an interpretatio whether AV Technology's armored vehicle is subject to the Federal Motor Vehicle Safety Standards (FMVSSs). As explained below, a vehicle manufactured to U.S. Army contract specifications, and sold to the Army, is not subject to the FMVSSs. In your letter, you explained that AV Technology is in the process of responding to a Department of the Army draft specification for an armored security vehicle. AV Technology proposes to offer its Dragoon ASV, an armored security vehicle, with a weapon carrying capability. Your letter states that the Dragoon ASV would be built to U.S. Army specification MIL-STD-1180. In a telephone conversation with Dorothy Nakama of my staff, you stated that the Dragoon ASV would also be built to other applicable military specifications. The FMVSSs' applicability to vehicles manufactured for and sold to the U.S. military, is addressed at 49 CFR 571.7(c): (c) Military vehicles. No standard applies to a vehicle or item of equipment manufactured for, and sold directly to, the Armed Forces of the United States in conformity with contractual specifications. You stated the Dragoon ASV would be manufactured to all applicable military specifications, specified by the Army. The Army is part of the 'Armed Forces.' Thus, when manufactured to Army contractual specifications, and sold to the Army, the Dragoon ASV is not subject to the FMVSSs. If you have any questions, please contact Dorothy Nakama of my staff at this address or at (202) 366-2992. Sincerely, John Womack Acting Chief Counsel; |
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ID: aiam2971OpenMr. W. G. Milby, Manager, Engineering Services, Blue Bird Body Company, P.O. Box 937, Fort Valley, GA 31030; Mr. W. G. Milby Manager Engineering Services Blue Bird Body Company P.O. Box 937 Fort Valley GA 31030; Dear Mr. Milby: This responds to your February 1, 1979, letter asking whether any la or regulation prohibits the remanufacture of a school bus with an old chassis and a new body when the completed vehicle does not comply with the new safety standards.; As you are aware, the agency has stated many times that such remanufactured vehicle need only comply with the standards in effect on the date of manufacture of the chassis as long as the remanufacturing process conforms to the guidelines established in Part 571.7(e) of our regulations. The agency does not view the remanufacturing problem as significant, because a vehicle's chassis normally wears out before its body. The recycling of noncomplying buses will cease when the supply of used chassis manufactured prior to April 1, 1977, disappears.; Sincerely, Frank Berndt, Acting Chief Counsel |
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ID: aiam2969OpenMr. W. G. Milby, Manager, Engineering Services, Blue Bird Body Company, P.O. Box 937, Fort Valley, GA 31030; Mr. W. G. Milby Manager Engineering Services Blue Bird Body Company P.O. Box 937 Fort Valley GA 31030; Dear Mr. Milby: This responds to your February 1, 1979, letter asking whether any la or regulation prohibits the remanufacture of a school bus with an old chassis and a new body when the completed vehicle does not comply with the new safety standards.; As you are aware, the agency has stated many times that such remanufactured vehicle need only comply with the standards in effect on the date of manufacture of the chassis as long as the remanufacturing process conforms to the guidelines established in Part 571.7(e) of our regulations. The agency does not view the remanufacturing problem as significant, because a vehicle's chassis normally wears out before its body. The recycling of noncomplying buses will cease when the supply of used chassis manufactured prior to April 1, 1977, disappears.; Sincerely, Frank Berndt, Acting Chief Counsel |
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ID: aiam2736OpenHoward Sturtz, M.D., 1479 Ygnacio Valley Road, Walnut Creek, California 94598; Howard Sturtz M.D. 1479 Ygnacio Valley Road Walnut Creek California 94598; Dear Dr. Sturtz: Mr. Ralph Nader forwarded to me your letter dated November 23, 1977 concerning your difficulty in determining whether your 1977 Ford Econoline van is equipped with an energy absorbing steering column.; Ford Econoline vans are equipped with conventional steering column that are not energy absorbing. Federal Motor Vehicle Safety Standards No. 203, *Steering Control Impact Protection*, and No. 204, *Steering Control Rearward Displacement*, are currently only applicable to passenger cars, so manufacturers are not required to have energy absorbing steering columns on van vehicles. Ford has not voluntarily equipped its vans with such steering systems.; The National Highway Traffic Safety Administration shares your concer in this subject. As a matter of fact, the agency has initiated high priority rulemaking proceedings to extend the applicability of Several passenger car standards, including Standards 203 and 204, to both vans and light trucks.; Please let me know if you would like further information on automotiv safety matters.; Sincerely, Howard J. Dugoff, Deputy Administrator |
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ID: aiam3761OpenMr. I. A. Wuddel, Westfalische Metall Industrie KG, Hueck & Co., Postfach 28 40, 4780 Lippstadt, Germany; Mr. I. A. Wuddel Westfalische Metall Industrie KG Hueck & Co. Postfach 28 40 4780 Lippstadt Germany; Dear Mr. Wuddel: This is in reply to your letter of September 9, 1983, to August Burget of this agency. With reference to the recent amendment to Motor Vehicle Safety Standard No. 108 permitting semi-sealed replaceable bulb headlamp systems, you have asked whether a headlamp assembly would be allowed which also incorporated a European H1 or H2 bulb, 'for an auxiliary driving beam or a front fog lamp, as our customer requests it.'; It is our understanding that the H1 bulbs are commonly used in Europea lamps as the principal lighting source, and that H2 bulbs are used in high intensity supplemental front lamps. Therefore, use of one of these bulbs in a replaceable bulb headlamp would create, in effect, a system of four headlamps. The agency recently denied a petition by Volkswagen for a four- lamp system at this time using the standardized replaceable light source (copy enclosed), because of unresolved issues. We therefore are currently unable to allow a system such as you propose with the H1 or H2 bulb in a common housing with the standardized replaceable light source, creating in effect a four- lamp headlamp system. Further, paragraph S4.1.3 of Standard No. 108, prohibits the installation of additional lighting equipment which impairs the effectiveness of lighting equipment required by Standard No. 108, and there is the distinct possibility that this could occur through incorporation of the H1 and H2 bulbs.; Use of the H1 and H2 bulbs in separate and independent units fo driving or fog lamps remains permissible, subject to regulation by the individual American States, as these items are not covered by Standard No. 108.; You may be interested to know that Volkswagen of America has recentl petitioned us for rulemaking that would allow use of the H4 bulb instead of the standardized replaceable light source in replaceable bulb headlamp systems. A decision is pending whether to grant this petition.; Sincerely, Frank Berndt, Chief Counsel |
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ID: aiam3019OpenMr. Eugene S. Trioli, 24 Wedgemere Road, Malden, MA 02148; Mr. Eugene S. Trioli 24 Wedgemere Road Malden MA 02148; Dear Mr. Trioli: This responds to your recent letter requesting information concernin the Federal requirements that would be applicable to auxiliary propane fuel systems for automobiles, which you would like to market in the United States.; Federal Motor Vehicle Safety Standard No. 301-75, *Fuel Syste Integrity*, (copy enclosed) specifies performance requirements for fuel systems on motor vehicles. Although the standard applies to completed vehicles rather than to fuel tanks or other fuel system components, there are requirements of which you should be aware if you intend to market auxiliary fuel systems. An original vehicle manufacturer that uses your auxiliary system, General Motors for example, has to certify that the entire vehicle complies with all applicable safety standards.; A person who mounts an auxiliary fuel tank or system on a new moto vehicle before the vehicle's first purchase in good faith for purposes other than resale is a vehicle alterer under the National Highway Traffic Safety Administration regulations. That person is required by 49 CFR 567.7 (copy enclosed) to affix a label to the vehicle stating that, *as altered*, the vehicle conforms to all applicable Federal Motor Vehicle Safety Standards--including Standard No. 301-75.; In addition, the mounting of an auxiliary or replacement fuel tank on motor vehicle after the vehicle's first purchase in good faith for purposes other than resale is affected by Section 108(a)(2)(A) of the National Traffic and Motor Vehicle Safety Act of 1966, as amended (15 U.S.C. 1397(a)(2)(A)). That section specifies in relevant part that:; >>>No manufacturer, distributor, dealer, or motor vehicle repai business shall *knowingly render inoperative*, in whole or part, any device or element of design installed on or in a motor vehicle or item of motor vehicle equipment in compliance with an applicable Federal motor vehicle safety standard.... (Emphasis added.)<<<; Therefore, the mounting of an auxiliary fuel tank or system on a use vehicle must be performed in such a way that the vehicles's compliance with Standard No. 301-75 is not knowingly compromised.; Sincerely, Frank Berndt, Chief Counsel |
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ID: aiam1215OpenMr. Keitaro Nakajima, 1099 Wall Street, West, Lyndhurst, NJ 07071; Mr. Keitaro Nakajima 1099 Wall Street West Lyndhurst NJ 07071; Dear Mr. Nakajima: This is in reply to your letter of July 24, 1973, concerning th meaning of the phrase 'remain in adjustment' in S5.3.5 of Motor Vehicle Safety Standard No. 215. You ask whether this criterion, when applied to the alignment of the front wheels, would permit misalignment as a result of the test, so long as the misalignment could be corrected to within the 'inspection limit' under which vehicle operation is considered to be normal.; Our reply is that impact-related misalignment beyond the inspectio limit is considered to be a noncompliance with S5.3.5, even though a mechanic could bring the wheel within the inspection limit without recourse to extraordinary techniques. Some variance in alignment would be permitted, in that tests are begun with the wheels aligned as closely as possible to the manufacturer's nominal adjustment limit which may be tighter than the inspection limit. This variance, however, is considerably less than what you envision in your letter.; Yours truly, Richard B. Dyson, Assistant Chief Counsel |
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ID: aiam0057OpenMr. A. D. Prickett, Chief Engineer - Special Duties, Joseph Lucas Limited, Great King Street, Birmingham 19, England; Mr. A. D. Prickett Chief Engineer - Special Duties Joseph Lucas Limited Great King Street Birmingham 19 England; Dear Mr. Prickett: Thank you for your letter of March 1, 1968, to the Deputy Director National Highway Safety Bureau, concerning your interpretation of certain requirements of Motor Vehicle Safety Standard No. 108.; The installation requirements contained in the SAE Standards that ar referenced in Standard No. 108 are enforceable requirements unless specifically exempted by Standard No. 108. With respect to the installation of license plate lamps, Standard No. 108 provides an exception to the 'Installation Recommendations' contained in SAE Standard J587b, in that Standard No. 108 requires a location 'at rear license plate.' This exception permits installation of the lamp at the top, sides or bottom of the license plate, instead of top and sides only as specified by SAE installation recommendations.; With two exceptions, the lighting devices required by Standard No. 10 must use bulbs conforming to SAE Standard J573b and bulb sockets conforming to either SAE Standard J567b or SAE Standard J822. The two exceptions are (1) motorcycle headlamps conforming to SAE Standard J584, and (2) disposable (throw-away) type lamp assemblies (other than sealed-beam headlamps) that do not use sockets. Sealed-beam headlamps must conform to SAE Standards J579a and J580a which, in turn, require sealed units conforming to SAE Standard J573b, but do not require sockets conforming to SAE Standards J567b or J822. The disposable type lamps((2) above) are excepted from the requirements of SAE Standard J567b since they are equipped with non-replaceable bulbs and electrical connectors rather than sockets. It is to be noted that Standard No. 108 is not applicable to motorcycles until January 1, 1969.; Sincerely, David A. Fay, Office of Standards on Accident Avoidance Motor Vehicle Safety Performance Service; |
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ID: aiam4476OpenMr. Richard W. Ward Vice President K-D Lamp Company 1910 Elm Street Cincinnati, OH 45210; Mr. Richard W. Ward Vice President K-D Lamp Company 1910 Elm Street Cincinnati OH 45210; "Dear Mr. Ward: This is in reply to your letter of September 14, l988 asking for a clarification of Federal requirements for the minimum lens area for turn signal lamps and stop lamps. The understanding expressed in your letter is correct. The SAE materials for turn signal lamps and stop lamps for wide vehicles incorporated by reference in Table I apply to original equipment on vehicles currently being manufactured, and to equipment intended to replace such original equipment. These standards were expressly incorporated to supersede earlier versions of SAE standards for turn signal lamps and stop lamps. However, in recognition that original equipment lamps made to earlier SAE specifications might not be compatible with the electrical systems of vehicles designed to conform to later SAE specifications, the agency adopted paragraphs S4.l.l.6 and 4.l.l.7, allowing the continued manufacture for replacement purposes only, of turn signal lamps and stop lamps designed to conform to earlier specifications. Both sections incorporate in their text portions of the earlier SAE standards. Because the earlier specification for turn signal lamps, J588d, required an effective projected luminous area not less than 12 square inches for turn signal lamps on wide vehicles, this requirement is also specified in S4.1.1.7 for replacement lamps manufactured in conformance with J588d. In short, your interpretation is correct with respect to turn signal lamps manufactured for installation on vehicles whose overall width is 80 inches or more. Single compartment turn signal lamps designed to conform to SAE J588e need meet only a minimum luminous lens area of 8 square inches. But if a turn signal lamp is manufactured to replace a turn signal lamp that was designed to conform to SAE J588d, its minimum luminous lens area is 12 square inches. I hope this clarifies the matter for your customer. Sincerely, Erika Z. Jones Chief Counsel"; |
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.