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: aiam2990OpenMr. Thomas E. Cole, Vice President, Tire Division, Rubber Manufacturers Association, 1901 Pennsylvania Ave., N.W., Washington, DC 20006; Mr. Thomas E. Cole Vice President Tire Division Rubber Manufacturers Association 1901 Pennsylvania Ave. N.W. Washington DC 20006; Dear Mr. Cole: In your letter of March 19, you pointed out that the tire industry ha printed tire tread labels and consumer information materials based on Figure 2 of the Uniform Tire Quality Grading (UTQG) Standards (49 CFR 575.104), as published in the National Highway Traffic Safety Administration's (NHTSA) Docket 25, Notice 24 (43 FR 30542, July 17, 1978). That notice contained a typographical error in the text of Figure 2, which was corrected in Notice 31 (44 FR 15721, March 15, 1979) by substitution of the word 'are' in place of the word 'of' in the first line of the third section of Figure 2.; The labels and other materials printed prior to the issuance of Notic 31 may be technically in noncompliance with the UTQG regulation. To avoid the waste which would result if use of these materials were prohibited, however, NHTSA will permit use of tread labels and information materials containing the Figure 2 text as stated in Notice 24, where orders for printing of these materials were submitted prior to March 15, 1979, the date of publication of Notice 31.; Sincerely, Michael M. Finkelstein, Associate Administrator fo Rulemaking; |
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ID: aiam0104OpenMr. Harry G. Seitz, Driver Education Coordinator, Cleveland Public Schools, 1380 East Sixth Street, Cleveland, Ohio 44114; Mr. Harry G. Seitz Driver Education Coordinator Cleveland Public Schools 1380 East Sixth Street Cleveland Ohio 44114; Dear Mr. Seitz: Your letter of July 3, 1968, addressed to Mr. George C. Nield, of th National Highway Safety Bureau has been forwarded to my office for reply.; The installation of dual controls on driver education cars is not *pe se* in violation of the Federal motor vehicle safety standards. However, the secondary equipment must meet the same safety standards established or the primary controls. The secondary steering column must fulfill the same requirements made for the primary column as set forth in Federal Motor Vehicle Safety Standards Nos. 203 and 204. The installation of an additional foot brake must not affect compliance with Standard No. 105. However, duplicate compliance with the control location and identification requirements of Standard No. 101 is not required since the 'driver' of such a vehicle remains the person seated behind the primary controls. For the same reason the 'driver' mirror requirements of Standard No. 111 apply only with respect to the person seated at the primary controls.; Changes may be made to original equipment when necessary fo installation of secondary controls but none of the standards requirements specified may be eliminated or adversely affected by the alteration.; You may make available copies of this letter to dealers and intereste parties.; Sincerely, Eugene B. Laskin, Acting Director, Office of Standard Preparation; |
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ID: aiam2139OpenMr. Robert L. Webber, Vice President, American Sports Co. Inc., P. O. Box 5603, 2970 East Maria Street, Compton, CA 90221; Mr. Robert L. Webber Vice President American Sports Co. Inc. P. O. Box 5603 2970 East Maria Street Compton CA 90221; Dear Mr. Webber: This is in response to your request of November 21, 1975, for a opinion regarding requirements for certifying universal sized helmets pursuant to Federal Motor Vehicle Safety Standard No. 218.; The requirements of Standard No. 218, *Motorcycle Helmets*, apply t helmets that fit headform size C. This includes the case where, by means of an adjusting mechanism supplied by the manufacturer for the purpose of permitting adjustment to headform size C, the helmet can readily be made to fit headform size C. Thus, any helmet that the manufacturer intends for use by persons with heads in the size C range must meet the requirements of the standard, including the requirement to affix the label required by section 5.6.1 of the standard.; The 'universal' helmet described in your letter seems to fall withi these guidelines in that it is intended to fit, *inter* *alia*, the size C headform. Therefore, notwithstanding the fact that it may also be adjusted to fit other size headforms, it should meet the requirements of FMVSS No. 218, including the labeling requirements.; Yours truly, Richard B. Dyson, Assistant 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: aiam0554OpenMr. H. Braun, Engineering Supervisor - Production, Motor Coach Industries, Inc., Pembina, ND 58271; Mr. H. Braun Engineering Supervisor - Production Motor Coach Industries Inc. Pembina ND 58271; Dear Mr. Braun: This is in reply to your letter of October 23, 1972, in which you as whether it is permissible under the Certification regulations for you to list alternative tire sizes and gross axle weight ratings on certification labels for vehicles which you sell without tires, but on which you apparently install them before delivery. You indicate that the tires are supplied by the customer, which he either owns, leases, or purchases from you.; Under the Certification regulation, you may if you wish lis alternative tire sizes, and alternative gross vehicle or gross axle weight ratings, as you described in your letter. If you install the tires, regardless of whether they are owned by the vehicle purchaser, leased, or purchased from you, the tire you install should be one of the alternative sizes listed on the certification label.; Yours truly, Richard B. Dyson, Assistant Chief Counsel |
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ID: aiam2569OpenHonorable John W. Wydler, House of Representatives, Washington, DC 20515; Honorable John W. Wydler House of Representatives Washington DC 20515; Dear Mr. Wydler: Thank you for your letter of April 21, 1977, requesting informatio concerning Federal regulations regarding school bus safety on behalf of your constituent, Mrs. Peter Peugeot of Rockville Centre, New York.; I have enclosed a document, 'Summary Description of Motor Vehicl Safety Standards Applicable to Buses,' which should be helpful to Mrs. Peugeot. I have also enclosed an informational summary, 'Where to Obtain Motor Vehicle Safety Standards and Regulations,' along with a set of forms from our Technical Reference Branch indicating how specific information may be retrieved through computer assisted literature searches along with an outline of fees for this service.; In addition to the above material, I have enclosed an order form fo the entire set of Federal motor vehicle safety standards and regulations, in case Mrs. Peugeot desires this specific volume. I would call her attention to the fact that although this document is relatively expensive, it is furnished in loose-leaf form and is updated periodically for an indefinite period with the latest amendments and changes at no additional cost.; I trust this information and material will be of value to Mrs. Peugeot If I can be of further assistance, please do not hesitate to contact me.; Sincerely, Robert L. Carter, Associate Administrator, Motor Vehicl Programs; |
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ID: aiam2093OpenMr. C. Brad Woodford, Swan and Woodford, 325 West Southern Avenue, Suite 9, Tempe, Arizona 85282; Mr. C. Brad Woodford Swan and Woodford 325 West Southern Avenue Suite 9 Tempe Arizona 85282; Dear Mr. Woodford: #This responds to your August 27, 1975, request fo standard applicable to glass-belted tires with the size designation H78-15 which were standard equipment on a 1973 Ford automobile. Such tires are subject to Federal Motor Vehicle Safety Standard No. 109, *New Pneumatic Tires--Passenger Cars*, a copy of which is enclosed. #Yours truly, Richard B. Dyson, Assistant Chief Counsel; |
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ID: aiam4844OpenMr. Leonard M. Anderson Vice President, Engineering Miller Trailers, Inc. P. O. Box 511 Bradenton, Florida 34206; Mr. Leonard M. Anderson Vice President Engineering Miller Trailers Inc. P. O. Box 511 Bradenton Florida 34206; "Dear Mr. Anderson: This responds to your request for an interpretatio of 49 CFR Part 565, Vehicle Identification Number - Content Requirements. More specifically, you asked whether a world manufacturer identifier (WMI) that was assigned to one manufacturer may continue to be used by a different manufacturer when it purchases the assets of the manufacturer to which the WMI was assigned. As explained below, the answer to your question is no. Your letter set forth the following information. Miller Trailer, Inc. (Miller) is a trailer manufacturer that has been assigned a unique WMI, in accordance with 49 CFR 565.5(c). Oshkosh Truck Corporation (Oshkosh) is a manufacturer of primarily trucks and some specialized trailers. Oshkosh has also been assigned a unique WMI in accordance with 49 CFR 565.5(c). Oshkosh is purchasing Miller. Your question is whether Oshkosh can continue to use Miller's WMI to identify trailers Oshkosh produces at the facilities that were formerly used by Miller. To answer this question, we must apply the regulatory provision of 49 CFR 565.4(a). That section provides that the WMI 'shall uniquely identify the manufacturer, make and type of the motor vehicle if the manufacturer produces 500 or more motor vehicles of its type annually.' NHTSA has previously interpreted the requirement that the WMI 'uniquely identify the manufacturer' as precluding the use of a WMI assigned to one manufacturer by any other manufacturer. For your information, I have enclosed a December 24, 1984 letter to Mr. Richard Bond, in which the agency explained that a newly-formed, wholly-owned subsidiary could not use the parent corporation's WMI to identify trailers formerly manufactured by the parent corporation. With respect to your situation, this regulatory requirement means that the VIN assigned to each trailer manufactured by Oshkosh must identify Oshkosh as the manufacturer. This identification will facilitate the quick and accurate identification of the actual vehicle manufacturer in the event there is a need to do so. Please note also that Oshkosh, upon manufacturing trailers that formerly were manufactured by Miller, has a responsibility to report any new types of motor vehicles that it produces. 49 CFR Part 566 requires manufacturers that have previously submitted identification information to keep their entries current by submitting revised information not later than 30 days after the relevant changes occur. A copy of this part is also enclosed for your information. I hope this information is helpful. If you have any further questions on this subject, please contact Dorothy Nakama of my staff at this address or at (202) 366-2992. Sincerely, Paul Jackson Rice Chief Counsel Enclosures"; |
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ID: aiam1892OpenHonorable Edwin B. Forsythe, House of Representatives, Washington, DC 20515; Honorable Edwin B. Forsythe House of Representatives Washington DC 20515; Dear Mr. Forsythe: This is in response to your letter of March 31, 1975, requestin information concerning correspondence from one of your constituents, Mr. Anthony N. D'Elia, commenting on a proposed amendment to the Federal Bumper Standard.; On January 2, 1975, the National Highway Traffic Safety Administratio (NHTSA) issued a Federal Register Notice (copy enclosed) proposing to reduce the current 5 mph bumper impact requirements to 2.5 mph until the 1979 model year. The impact requirements would have been increased to 4 mph for 1979 and later model year cars.; The proposal was based primarily on the results of two agency sponsored studies which indicated that the cost and weight of many current production bumpers, in light of inflation and fuel shortages, made the bumpers no longer cost beneficial. Information presented at public hearings on the bumper notice and comments submitted to the docket in response to the proposal have brought to light additional data. The NHTSA has carefully examined all of this evidence and reviewed its studies in light of the new information. As a result, the agency has concluded that the 5 mph protection level should not be reduced. This decision is contained in a Federal Register notice that was published March 12, 1975, which is enclosed (Docket No. 74-11, Notice 7, Docket No. 73-19, Notice 6).; Another public hearing was held on April 4, 1975, to allow ora presentation of views on the March 12 notice. The agency is currently examining the information gathered at that proceeding in addition to the written comments that have been submitted. The next step in our rulemaking process will be based on all of the data available.; Your interest and that of Mr. D'Elia is greatly appreciated. Sincerely, James C. Schultz, Chief Counsel |
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ID: aiam0780OpenMr. J. C. Eckhold,Automotive Safety Director,Ford Motor Company,The American Road,Dearborn, Michigan 48121; Mr. J. C. Eckhold Automotive Safety Director Ford Motor Company The American Road Dearborn Michigan 48121; Dear Mr. Eckhold:#This is in reply to your letter of June 20, 1972, t Mr. Toms concerning general reference material in support of the proposals contained in Docket No. 70-27.*Hydrauli- c Brake Systems.* You ask that the NHTSA place in the file 'The supporting data upon which the test sequence is based as well as the data used to determine the performance values based on the sequence.'#The proposed test sequence is based primarily upon the test sequence of standard No. 105, which is that if SAE Recommended Practice J937 incorporated by reference. Parking brake, lightly loaded vehicle, inoperative brake power assist unit, and partial failure tests not included in J937, were placed in the sequence in order that appeared, in the judgment of agency personnel, most likely to provide realistic and undistorted results. The sequence, of course, is subject to revision on the same basis in the forthcoming final rule. General reference material in the Docket includes data from braking tests of eighteen 1970 automobiles, NBS Technical Note 557,'The Brake Pedal Forces Capability of Adult Females,' and SAE 7200032,'Eval- uation of the use of Automotive Braking Systems During a 7300 Mile Cross-County Trip.'#Sincerely,Lawrence R. Schneider,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.