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: aiam3840OpenMr. Dietmar K. Haenchen, Executive Engineer, Vehicle Regulations, Volkswagen of America, Inc., P.O. Box 3951, Troy, MI 48007-3951; Mr. Dietmar K. Haenchen Executive Engineer Vehicle Regulations Volkswagen of America Inc. P.O. Box 3951 Troy MI 48007-3951; Dear Mr. Haenchen: This is in reply to your letter of April 25, 1984, asking two question with respect to the humidity test for replaceable bulb headlamps specified in Motor Vehicle Safety Standard No. 108.; With reference to paragraph S6.8, you mention the relative humidit figure of 90 *+* 10 percent, and your interpretation that the six-hour cycle of the test should be run at 90 percent and that the 10 percent tolerance 'is intended to cover any drift in the instrumentation, controls and the process of generating this humidity.' We concur that this is a reasonable interpretation of this requirement.; You have also asked when the headlamp must be inspected after th humidity test, as paragraph S4.1.1.36(d)(7) is silent on this point. It is your interpretation that this inspection must occur directly following the test, and before the photometrics of the lamp are measured, even though, in your view, it would be more convenient to check it after the photometric test. Your interpretation is correct, this inspection must occur within the 9 to 11 minutes specified for beginning the photometric test after completion of the humidity test.; Sincerely, Frank Berndt, Chief Counsel |
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ID: aiam5097OpenMr. David M. Hart President Flushsaver 5440 W. Century Boulevard Los Angeles, CA 90045-5992; Mr. David M. Hart President Flushsaver 5440 W. Century Boulevard Los Angeles CA 90045-5992; Dear Mr. Hart: This responds to your letter of November 16 asking fo 'feedback' on your plan to market a decal called 'Flashit' for installation over a center high-mounted stop lamp. I enclose a copy of an agency letter representative of our advice to inquirers on this subject. Though this letter, to David M. Romansky, dates from September 3, 1987, it remains the agency's position today. Should you wish to contact the American Association of Motor Vehicle Administrators on this subject, please note that its new address is 4600 Wilson Boulevard, Arlington, Va. 22203. Sincerely, Paul Jackson Rice Chief Counsel Enclosure; |
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ID: aiam2752OpenG. K. Pilz, Manager, Product Compliance, Mercedes-Benz of N.A., One Mercedes Drive, Montvale, NJ 07645; G. K. Pilz Manager Product Compliance Mercedes-Benz of N.A. One Mercedes Drive Montvale NJ 07645; Dear Mr. Pilz: This responds to your February 1, 1978, letter asking whether you certification label complies with the requirements of Part 567, *Certification*.Your certification would state the gross vehicle and axle weight ratings in both pounds and kilograms. In the past, the agency has permitted this approach for the purpose of international harmonization of measurements. Therefore, your proposed label appears to comply with the requirements.; Sincerely, Joseph J. Levin, Jr., Chief Counsel |
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ID: aiam0295OpenMr. Fred R. Kern, Senior Engineering Scientist, Bolt Beranek and Newman, Inc., 50 Moulton Street, Cambridge, MA 02138; Mr. Fred R. Kern Senior Engineering Scientist Bolt Beranek and Newman Inc. 50 Moulton Street Cambridge MA 02138; Dear Mr. Kern: This is in reply to your letter of February 5, 1971, concernin certification of child seating systems. Your letter asks whether the statement, 'This (child seating system) conforms to all applicable Federal Motor Vehicle Safety Standards in effect on the date of manufacture shown above,' or alternatively the symbol 'DOT,' may be used to certify that a child seating system complies with Standard No. 213. You also ask whether the certification statement may be placed on the label required on the child seat pursuant to S4.1 of the standard.; The statement that you submit is an adequate certification statement Furthermore, this statement or a similar statement may be placed on the label required pursuant to S4.1 of the standard, as the certification would therefore be 'in the form of a label or tag' on the item of motor vehicle equipment as specified in section 114 of the National Traffic and Motor Vehicle Safety Act (15 U.S.C. S1403).; With reference to use of the symbol 'DOT' for certifying child seatin systems, while this symbol is presently used by manufacturers to certify other items of motor vehicle equipment, its use as such is only pursuant to specific provisions of the standards. We cannot approve of its use for child seating systems without prior rulemaking.; We are pleased to be of assistance. Sincerely, Lawrence R. Schneider, Acting Chief Counsel |
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ID: aiam1257OpenMr. C.C. King, Southwestern Transportation Company, P.O. Box 6187, Dallas, Texas 75222; Mr. C.C. King Southwestern Transportation Company P.O. Box 6187 Dallas Texas 75222; Dear Mr. King: This is in reply to your letter of July 18, 1973, requestin information on an NHTSA ruling that you understand prohibits tire companies from surrendering damaged tires to carriers for salvage purposes.; The NHTSA has not issued a ruling in the precise terms you describe However, a recent amendment (copy enclosed) to the Federal motor vehicle safety standard applicable to passenger car tires, Standard No. 109, could be viewed as having that effect. The amendment prohibits the sale, the offer for sale, or the introduction or delivery for introduction in interstate commerce of any tire designed for use on a passenger car that fails to meet the requirements of the standard, unless the tire is altered so that it cannot be used or repaired for use on a motor vehicle (including a trailer). Tire manufacturers may be understandably reluctant to claim that damaged tires will still conform to the safety standard, and when altered so that their use as motor vehicle equipment is prevented. This may reduce their value for salvage purposes. There is no specific prohibition to their surrender for use as salvage, however, and they may have salvage value if a purpose if a purpose, such as scrap, unrelated to motor vehicles is intended for them.; Sincerely, Richard B. Dyson, Assistant Chief Counsel |
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ID: aiam3790OpenMr. A. J. DiMaggio, Manager, Gov. and Customer Relations, The Firestone Tire & Rubber Co., 1200 Firestone Parkway, Akron, OH 44317; Mr. A. J. DiMaggio Manager Gov. and Customer Relations The Firestone Tire & Rubber Co. 1200 Firestone Parkway Akron OH 44317; Dear Mr. DiMaggio: This is in reply to your letter of December 8, 1983, to th Administrator, petitioning for a determination that a noncompliance with Motor Vehicle Safety Standard No. 117, *Retreaded Pneumatic Tires*, be deemed inconsequential as it relates to motor vehicle safety.; The noncompliance consists of omission of the 'DOT' certificatio symbol. You have represented that tires so affected nevertheless meet Standard No. 117 in all other respects.; It has been the policy of this agency since 1977 to treat omissions o the DOT symbol as failures to certify pursuant to Sections 114 and 108(a)(1)(C) of the National Traffic and Motor Vehicle Safety Act rather than as failures to comply with the Federal motor vehicle safety standard that requires or allows that method of certification. The symbol is not considered to establish a minimum standard of motor vehicle performance. This means that manufacturers who fail to provide the symbol are not required to conduct a notification and remedy campaign, and that accordingly the National Highway Traffic Safety Administration is not required to publish notices of petitions requesting inconsequentiality determinations.; Your petition is therefore moot. Thank you for bringing this matter t our attention.; Sincerely, Frank Berndt, Chief Counsel |
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ID: aiam4055OpenFinbarr J. O'Neill, Esq., General Counsel, Hyundai Motor America, 7373 Hunt Avenue, P.O. Box 2669, Garden Grove, CA 92642- 2669; Finbarr J. O'Neill Esq. General Counsel Hyundai Motor America 7373 Hunt Avenue P.O. Box 2669 Garden Grove CA 92642- 2669; Dear Mr. O'Neill: This responds to your letter asking about the requirements of FMVSS No 101, *Controls and Displays*, concerning the color of the highbeam telltale. You stated that while Table 2 of the standard indicates that a manufacturer has the option of choosing a green or blue telltale, your review of competitive vehicles shows that virtually all have chosen blue telltales. You asked whether NHTSA has taken any position as to whether one color is preferable to the other. You also asked for comment on whether NHTSA has any reasonable anticipation of changing this requirement.; I would note that in the past NHTSA required the highbeam telltale t be blue. That color was selected primarily to promote international harmonization of standards regulating vehicle controls and displays. Blue is the color requirement of the International Standards Organization, the Economic Commission for Europe, and the European Economic Community.; On January 21, 1982, NHTSA amended Standard No. 101 to permit green a an alternative to blue (47 FR 2996). The purpose of the change was to allow the use of light emitting diode technology, which at that time could not produce the color blue. While we do not have a preference as such as to how manufacturers choose to meet our standards, we would note that use of the color blue tends to promote international harmonization.; On September 12, 1985, NHTSA published in the Federal Register (50 F 37240) a notice of proposed rulemaking to amend FMVSS No. 101. Among other things, the proposal concerns color requirements for electronic displays. See 50 FR 37244. We have enclosed a copy of the notice for your convenience.; I hope this information is helpful. Sincerely, Erika Z. Jones, Chief Counsel |
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ID: aiam2882OpenMr. Richard H. Attenhofer, Manager - Tire Technical Relations, Dunlop Tire Company, P. O. Box 1109, Buffalo, New York 14240; Mr. Richard H. Attenhofer Manager - Tire Technical Relations Dunlop Tire Company P. O. Box 1109 Buffalo New York 14240; Dear Mr. Attenhofer: This responds to your July 10, 1978, letter asking whether it i permissible to label motorcycle tires with alternate speeds and load ratings appropriate for those speeds. You suggest that your tires be labeled with maximum speeds of 131, 137, and 143 miles per hour with the corresponding load ratings. The labeling of motor cycle (sic) tires is regulated by Standard No. 119, *New Pneumatic Tires for Vehicle Other Than Passenger Cars.*; Standard No. 119 requires that tires be marked with, among othe things, the maximum inflation pressure of the tire and the load rating applicable to that inflation pressure. Speed qualifications are permitted on tires when, for example, the tires are speed restricted. Otherwise, tires are not marked with speed criteria although they may be marked with the symbols S, H, or V as part of the tire identification number. These symbols, established by the European Tyre and Rim Technical Organization (ETRTO), indicate that the tire is an acceptable high-speed tire.; The National Highway Traffic Safety Administration considers i appropriate to permit the symbols S, H, or V to be marked on tires to indicate that such tires are appropriate for high-speed use. This permits, for example, a sophisticated purchaser of tires for emergency vehicles to know that the tires are suitable for the higher operational speeds necessary for those vehicles. The NHTSA, however, considers it inappropriate to mark motorcycle tires with maximum speeds of 131, 137, and 143 miles per hour with the corresponding safe load ratings. Such markings would appear to sanction the use of he tires at these speeds which far exceed the national speed limit.; Since Standard No. 119 regulates the permissible uses of spee designations on nonpassenger car tires, the agency interprets the standard to prohibit the marking of any other speed designations on a tire. The NHTSA considers the only appropriate speed designation on tires to be one that reflects a speed restricted tire or one that uses the symbols established by the ETRTO for tires that have been tested and can be operated at higher speeds.; Sincerely, Joseph J. Levin, Jr., Chief Counsel |
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ID: aiam1607OpenMr. B. J. Smith, President, Nabors Trailers, Inc., P.O. Box 979, Mansfield, LA 71052; Mr. B. J. Smith President Nabors Trailers Inc. P.O. Box 979 Mansfield LA 71052; Dear Mr. Smith: This responds to your August 21, 1974, question whether a 'logging pol trailer', which consists of a beam to which an axle-mounted bolster can be clamped at different points to accomodate (sic) different log lengths, qualifies as a heavy hauler trailer as that term is defined in Standard No. 121, *Air brake systems*:; >>>'Heavy hauler trailer' means a trailer with one or more of th following characteristics:; (1) Its brake lines are designed to adapt to separation or extension o the vehicle frame, or; (2) Its body consists only of a platform whose primary cargo-carryin surface is not more than 40 inches above the ground in an unloaded condition, except that it may include sides that are designed to be easily removable and a permanent 'front-end structure' as that term is used in S 393.106 of this title.<<<; This also acknowledges receipt of your September 5 and September 17 1974, letters on the same subject.; The logging pole trailer you describe is a heavy hauler trailer, and a such, Standard No. 121 does not apply to this trailer until September 1, 1976. The beam or 'reach', together with the bolster, constitutes the frame of the trailer, and the brake lines are designed to adapt to extension of the bolster element along the beam.; This arrangement differs from the standard highway van which has one-piece frame with an adjustable tandem axle. The purpose of this sliding arrangement is unrelated to an extension of the frame itself to accomodate (sic) the transportation of heavy or oversize loads.; Yours truly, Richard B. Dyson, Acting Chief Counsel |
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ID: aiam0915OpenMr. Pundalik K. Kamath, Senior Safety Engineer, Oshkosh Truck Corporation, Post Office Box 560, Oshkosh, WI 54901; Mr. Pundalik K. Kamath Senior Safety Engineer Oshkosh Truck Corporation Post Office Box 560 Oshkosh WI 54901; Dear Mr. Kamath:#In your letter of November 28, 1972, you ask about th applicability of Federal Motor Vehicle Safety Standard No. 101 to a wiper for the 'right-hand window'.#The control location, identification, and illumination requirements of Standard No. 101 apply only to windshield wiping systems, and not to those that may be provided for side or rear windows.#Yours truly, Richard B. Dyson, Assistant 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.