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: aiam3143OpenMr. M. Ogata, Branch Manager, Toyo Kogyo U.S.A., 23777 Greenfield Road, Suite 462, Southfield, Michigan 48075; Mr. M. Ogata Branch Manager Toyo Kogyo U.S.A. 23777 Greenfield Road Suite 462 Southfield Michigan 48075; Dear Mr. Ogata: This letter is in response to your October 19, 1979, request for an interpretation of the requirements of Federal Motor Vehicle Safety Standard No. 110 and 49 CFR Part 575. Specifically, you inquired if it is permissible for Mazda to place information concerning the 185SR13 tire size on the tire placard, as required by section 4.3(d) of Standard No. 110, and in the consumer information booklet, as required by 49 CFR S 575.102(c)(2), for vehicles which may have 185HR13 tires installed by dealers at a customer's request. This would be permissible.; A 185SR13 tire and a 185HR13 tire are the same size and have the sam load-carrying capacity. The 'S' and 'H' only denote different high-speed capabilities for what are, otherwise, identical tires.; This agency requires the manufacturer to list recommended tire sizes o the tire placard and in the consumer information booklet for two reasons. First, the information is required to ensure that any replacement tires installed on the vehicle will be a proper size for the rims mounted on that vehicle. Second, the information helps to ensure that the tires installed on the vehicle will have sufficient load-carrying capacity to be used safely on that particular vehicle. Neither of these safety concerns would be frustrated by a manufacturer putting information on the placard and in the booklet about a tire with a lower speed rating. Therefore, your proposed plan would not violate any of our consumer information regulations.; Sincerely, Frank Berndt, Chief Counsel |
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ID: aiam4686OpenMr. Malcolm B. Mathieson Vice President, Engineering Thomas Built Buses, Inc. P.O. Box 2450 High Point, NC 27261; Mr. Malcolm B. Mathieson Vice President Engineering Thomas Built Buses Inc. P.O. Box 2450 High Point NC 27261; Dear Mr. Mathieson: This responds to your letter to former Chie Counsel Erika Jones concerning the application of Federal Motor Vehicle Safety Standard (FMVSS) No. 217, Bus Window Retention and Release to school buses. I apologize for the delay in responding to your inquiry. Your letter expressed concern about a recent opinion from the Federal Highway Administration (FHWA) which states that school buses used in interstate commerce and thus subject to FHWA's Federal Motor Carrier Safety Regulations (FMCSR's) are required by the FMCSR's to comply with the provisions in Standard No. 217 applicable to buses other than school buses. Your letter included copies of a recent letter from Thomas Buses to FHWA on this issue, as well past interpretations by FHWA and this agency. As you are aware, Standard No. 217 contains specific emergency exit requirements for school buses, as well as requirements for other buses. As noted in your letter to FHWA, and in our past interpretations, including the July 5, 1984 letter to Ron Marion that you enclosed, it is NHTSA's position that all buses sold as school buses must comply with the school bus requirements in Standard No. 217. We recognize that this position may conflict with FHWA's interpretation of their regulations, and we are seeking resolution of this issue with FHWA to resolve any inconsistencies between the FMVSS's and the FMCSR's. I hope you have found this information helpful. Please do not hesitate to contact this office if you have further questions. Sincerely, Paul Jackson Rice Chief Counsel; |
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ID: aiam1484OpenMr. Tatsuo Kato, Staff, Safety, Nissan Motor Company, Ltd., 560 Sylvan Avenue, Englewood Cliffs, NJ 07632; Mr. Tatsuo Kato Staff Safety Nissan Motor Company Ltd. 560 Sylvan Avenue Englewood Cliffs NJ 07632; Dear Mr. Kato:#This is in reply to your letter of April 23, 1974 asking for an interpretation of Standard No. 101, as proposed in the *Federal Register* on September 27, 1973. You reference that portion of Paragraph S4.3.3 which states 'If illumination of controls and displays not listed in Paragraph S4.1 is provided, its intensity shall be variable in a manner that complies with this paragraph'.#The basic requirement of S4.3.3 is that 'A control shall be provided to adjust the intensity of control and display illumination. . . .' We interpret the basic requirement as applying to *all* control and display illumination, not just illumination of the minimum number of controls and displays specified in Tables I and II. Thus if the manufacturer chooses to provide illumination for *any* control or display, even those not related to safety such as the radio or clock, its intensity shall be variable in accordance with Paragraph S4.3.3.#Yours truly, Richard B. Dyson, Assistant Chief Counsel; |
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ID: aiam2302OpenMr. Earl M. Hoosline, 109 North 'E' Street, Livingston, MT 59047; Mr. Earl M. Hoosline 109 North 'E' Street Livingston MT 59047; Dear Mr. Hoosline: This is in response to your letter of April 11, 1976, requestin information concerning your daughter's purchase of a 1972 Plymouth whose odometer was allegedly rolled back.; The Motor Vehicle Information and Cost Savings Act (Pub. L. 92-513 prohibits alteration of the mileage indicated on an odometer and requires that a written disclosure of a vehicle's mileage be provided by the seller to the purchaser at the time the ownership of a vehicle is transferred. If the correct mileage is unknown, however, the Act requires a statement to that effect to be furnished in written form to the buyer. There is no requirement that these disclosure statements be retained by either the transferor or the transferee.; Violation of any of the above requirements may subject the violated t civil liability where his actions were intended to defraud the purchaser. The Act makes available to the buyer a remedy in the amount of $1,500 or treble damages, whichever is greater. To obtain this remedy, section 409 of the Act provides that a private civil action be instituted in State or Federal court.; If a vehicle has traveled over 100,000 miles and this is not reflecte on the odometer, the odometer disclosure statement should indicate that the mileage registered on the odometer does not reflect the true number of miles the vehicle has driven. If the suggested Federal form is used in making the disclosure, the following statement should be checked:; >>>'I further state that the actual mileage differs from the odomete reading for reasons other than odometer calibration error and that the actual mileage is unknown.'<<<; However, since the actual mileage would be known in the case where th odometer had simply passed the 100,000 mark, the seller should state what the actual mileage is.; For your information, I am forwarding copies of the relevant portion of the Act and the disclosure requirements, in addition to the consumer information pamphlet on odometers.; Sincerely, John Womack, Assistant Chief Counsel |
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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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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.