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: aiam3894OpenMr. Bernt Svensson, Marketing Director, Viskafors Gummifabrik AB, Box 2059, S-515 02 Viskafors, SWEDEN; Mr. Bernt Svensson Marketing Director Viskafors Gummifabrik AB Box 2059 S-515 02 Viskafors SWEDEN; Dear Mr. Svensson: This responds to your letter to Ms. Kathleen DeMeter of my staff asking for information on how to get a new temporary spare tire size included in the tire tables following Standard No. 109, * New Pneumatic Tires -- Passenger Cars* (49 CFR S571.109). The agency rescinded tire tables in Standard No. 109 in a final rule published at 46 FR 61473, December 17, 1981. I have enclosed a copy of that rule together with a current copy of Standard No. 109 for your records.; Section S4.4.1 requires tire manufacturers to provide a listing of th rims that may be used with each tire size it produces. Section S4.2.1(c) requires a tire's load rating be the load rating for that size specified in a submission under S4.4.1. This may be provided by the manufacturer in a document furnished to each of the manufacturer's dealers, to this agency, and to the pubic upon request. Alternatively, the manufacturer may use the data for that tire size shown in a current publication of one of the standardization organization listed in S4.4.1(b). Your company will have to use one of these two means of complying with this requirement, instead of relying on the tire tables, as was formerly done.; The current publication of the American standardization organizatio the Tire & Rim Association) shows no listing for the tire size about which you inquired. It is possible that the size is listed by one of the other standardization organization of your choosing or submit the data directly to this agency, all your dealers and the public, upon request.; Should you have any further questions on this matter, please contac Mr. Stephen Kratzke of my staff at this address.; Sincerely, Frank Berndt, Chief Counsel |
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ID: aiam5254OpenMr. Tom DeLapp Executive Coach Builders, Inc. One Executive Blvd. Springfield, MO 65802; Mr. Tom DeLapp Executive Coach Builders Inc. One Executive Blvd. Springfield MO 65802; Dear Mr. DeLapp: This responds to your letter of August 18, 1993 concerning a modification you wish to make on limousines manufactured by your company. You wish to modify the hinge assembly controlling forward and reclining movement of the front seat to provide access to the area between the front of the privacy panel and the back of the front seat. (The area contains auxiliary fuse panels and relays.) The modification would involve removal of a metal pin in the hinge assembly, allowing the seat to articulate forward to a greater degree. You asked whether Standard No. 207, Seating Systems, prohibits the removal of a limiting pin or limits forward movement of a seat back. Standard No. 207 specifies strength and other performance requirements for seats in passenger cars, multipurpose passenger vehicles, trucks, and buses. Section S4.3 of Standard No. 207 contains requirements for hinged or folding seat backs, except for passenger seats in buses or a seat adjustable only for its occupants. Section S4.3(a) requires a self-locking device for restraining the hinged or folding seat back. Section S4.3.2 contains performance requirements for this restraining device. Section S4.3 does not limit the degree of movement of a hinged or folding seat back. Thus, you may remove the limiting pin if removing it only increases the degree of movement of the seat. However, the seat must still meet the requirements of S4.3 with the pin removed. Accordingly, the seat must have a self-locking device that can withstand the force applications specified in S4.3.2.1 and acceleration specified in S4.3.2.2. I hope you find this information helpful. If you have any other questions, please contact Mary Versailles of my staff at this address or by phone at (202) 366-2992. Sincerely, John Womack Acting Chief Counsel; |
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ID: aiam1750OpenHonorable John B. Anderson, House of Representatives, Washington, DC 20515; Honorable John B. Anderson House of Representatives Washington DC 20515; Dear Mr. Anderson: This responds to your request for consideration of Mr. George H Dobson's December 27, 1974, request for reconsideration of Standard No. 121, *Air brake systems*, because of its costs.; Standard No. 121 requires that newly-manufactured air-braked vehicle stop from speeds of up to 60 mph on wet and dry surfaces in the loaded and unloaded condition, without leaving a 12-foot-wide lane and without lockup of wheels above 10 mph. These performance requirements are based on a safety need for improved braking performance on air brake- equipped highway vehicles. Controlled stopping within the traffic lane is particularly important to tractor-trailer combinations to avoid 'jackknife' skids. The incompatibility of vehicle sizes can be reduced significantly by establishing equal stopping distances for trucks and passenger cars.; We have analyzed the costs and benefits to be gained in upgradin truck, bus, and trailer braking performance and have concluded that the savings in lives, injury, and property damage justify the incremental costs of this standard. Standard 121 does not require retrofit of vehicles manufactured prior to the standard's effective date.; From a cost standpoint, it is noteworthy that the arguments fo increased weight limits for commercial vehicles relied, in part, on the increased braking performance of vehicles which meet Standard No. 121. A major reason for the heavier vehicles would be to reduce the costs of transportation, and Standard No. 121 contributes directly to that goal.; As you may be aware, the NHTSA has in fact proposed postponement of th standard due to the current economic situation. Based on several hundred comments, there was persuasive evidence that a delay at this late date would create far greater dislocation in the automotive industry than would a January 1, 1975, implementation. A copy of our decision not to postpone the standard is enclosed.; Yours truly, Richard B. Dyson, Acting Chief Counsel |
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ID: aiam2107OpenMr. John B. White, Engineering Manager, Technical Information Dept., Michelin Tire Corporation, P. O. Box 3467, New Hyde Park P. O., NY 11040; Mr. John B. White Engineering Manager Technical Information Dept. Michelin Tire Corporation P. O. Box 3467 New Hyde Park P. O. NY 11040; Dear Mr. White: This is in response to your letter of October 17, 1975, concerning th importation into the United States of tires that will be mounted on trucks intended for export from the United States.; 49 CFR Part 571.7(d) and Section 108(b)(5) of the National Traffic an Motor Vehicle Safety Act of 1966 specify that no Federal Motor Vehicle Safety Standards (FMVSS) apply to; >>>a motor vehicle or item of motor vehicle equipment intended solel for export, and so labeled or tagged on the vehicle or item itself and on the outside of the container, if any, which is exported.<<<; Therefore, tires which Michelin manufactures for sale directly to truck manufacturer who will mount them on trucks which are intended solely for export need not comply with Standard No. 119, *New Pneumatic Tires for Vehicles Other than Passenger Cars*. When imported and shipped to the truck manufacturer, the tires must bear a label or tag indicating intent to export. Such a label must also appear on the outside of the container, if any, in which the tires are shipped. Importation of such tires is permitted by 19 CFR 12.80(b)(1)(ii), provided they are so labeled. A label need not remain on the tires after they have been mounted on the trucks, provided that the trucks bear similar labels.; Because these tires are not subject to any FMVSS and are beyond th scope of any expected defect notification and remedy program, Michelin Tire Corporation is not subject to the requirements of 49 CFR Part 574, *Tire Identification and Recordkeeping*, with respect to them.; Sincerely, Frank A. Berndt, Acting Chief Counsel |
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ID: aiam5011OpenThe Honorable Phil Gramm United States Senator 2323 Bryan Street, #1500 Dallas, TX 75201; The Honorable Phil Gramm United States Senator 2323 Bryan Street #1500 Dallas TX 75201; Dear Senator Gramm: This responds to your Memorandum attachin correspondence from your constituent Stephen Newmark of Tarrant County. Mr. Newmark, Vice-President of Lonestar Classics, Inc., states that his company 'has requested an exemption' from this agency 'for the purposes of manufacturing kit cars,' and asks your help 'in determining whether our exemption will be granted or whether the National Highway Traffic Safety Administration (NHTSA) requires further information.' He also states that 'the timing of NHTSA's response is critical to our moving ahead.' Mr. Newmark FAXED the Administrator on May 5, 1992, about the possibility of obtaining an exemption, and followed up with a telephone call to the Office of Chief Counsel on May 15. As we understand it from that conversation, the business plan intended by Lonestar is to sell and deliver a certain number of unassembled components to purchasers who will complete the assembly of the vehicle by providing the engine, drive train, and suspension. We informed Mr. Newmark orally that, given these facts, Lonestar is not considered to be a 'manufacturer' of motor vehicles under the National Traffic and Motor Vehicle Safety Act. Because of this, Lonestar is not required to ensure the compliance of the completed vehicle with the Federal motor vehicle safety standards, and, hence, no exemption is required for it to implement its business plan. We informed Mr. Newmark of your interest in his behalf, and that our response to you would also serve as a reply to his FAX of the 5th to the Administrator. For this reason we are providing him a copy of this letter. Sincerely, Frederick H. Grubbe Enclosure: Constituent's Correspondence cc: Washington Office; |
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ID: aiam0287OpenMr. P.H.G. Morgan, Managing Director, Morgan Motor Company, Ltd., Pickersleigh Road, Malvern Link, Worchestershire, England; Mr. P.H.G. Morgan Managing Director Morgan Motor Company Ltd. Pickersleigh Road Malvern Link Worchestershire England; Dear Mr. Morgan: By letter of November 19, 1970, you petitioned for reconsideration o Federal Motor Vehicle Safety Standard No. 214 - Side Door Strength (35 F.R. 16801, October 30, 1970). After consideration of the issues raised by Morgan's petition, the National Highway Traffic Safety Administration has found no sufficient justification for amending the standard and the petition is therefore denied.; Your company's petition states that the standard presents difficultie for cutaway doors, and that the structure of Morgan automobiles supplies a measure of protection through flared side fenders that extend beneath the doors. The Administration recognizes that there is considerable variety in door and side structure. However, the need to protect occupants of all vehicles from injury in side collisions dictates a uniform measure of such protection, and the Administration has determined that the requirements of Standard No. 214 are reasonable, practicable and appropriate for passenger cars.; The remaining points in your letter of November 19, 1970, are mor nearly questions for interpretation than requests for reconsideration. Your second question pertains to the height (or length) of the loading device. The standard states only that the device must not contact any structure above the bottom edge of the door window opening. There is no other restriction on the maximum height of the test device, and it is not clear, without further explanation, why Morgan would be limited to a cylinder only 4 inches high.; Your remaining question deals with the positioning of side windows Although the standard specifies that side windows shall be in the uppermost position, it does not require that side windows exist and should not be so interpreted.; Sincerely, Douglas W. Toms, Acting Administrator |
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ID: aiam1654OpenMr. James H. Thomas, 8 North Queen Street, Griest Building, Lancaster, Pennsylvania 17603; Mr. James H. Thomas 8 North Queen Street Griest Building Lancaster Pennsylvania 17603; Dear Mr. Thomas: This is in reply to your letter of September 27,1974, requesting ou position regarding the micro-siping of tires. You also request copies of the government brief in *United States* v. *General Tire*.; The NHTSA does not consider the micro-siping process to be prohibite *per se* when applied to new motor vehicle tires subject to either Motor Vehicle Safety Standard No. 109, 49 CFR S571.109 (applicable to passenger car tires), or Motor Vehicle Safety Standard no. 119, 49 CFR S571.119 (applicable to tires for vehicles other than passenger cars). In the *General Tire* case, the particular tires involved have been micro-siped and were found to have failed certain laboratory wheel tests specified in Standard No. 109. The only issue in the case was General's responsibility for the failure and not whether the tires met the standard. General chose to stipulate that they did not.; This agency has no data on whether micro-siping adversely affects tire's ability to conform to the standards. It is possible that the quality of micro-siping may cause compliance problems. In any event, the agency does not consider micro-siped tires to fail to conform to either standard, unless there is an actual failure to meet the performance tests of the standards.; I have enclosed a copy of the government's brief in the Court o Appeals in the *General Tire* matter. There are other briefs in this litigation, but the agency's position is set forth in this brief and it should be satisfactory for your purposes.; We are pleased to be of assistance. Yours truly, Richard B. Dyson, Acting Chief Counsel |
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ID: aiam3812OpenMr. H. Nakaya, Office Manager, Mazda (North America), Inc., Detroit Office, 23777 Grenfield (sic) Road, Suite 462, Southfield, MI 48075; Mr. H. Nakaya Office Manager Mazda (North America) Inc. Detroit Office 23777 Grenfield (sic) Road Suite 462 Southfield MI 48075; Dear Mr. Nakaya: This responds to your letter requesting an interpretation of Standar No. 120, *Tire Selection and Rims for Motor Vehicles Other Than Passenger Cars* (49 CFR S571.120). Specifically, you noted that section S5.2 of that standard required that certain information be labeled on the 'weather side' of each rim or wheel disc. You then offered your interpretation of the term 'weather side', and asked for my comments on that interpretation. My comment is that Standard No. 120 explicitly defines 'weather side', and that the definition of the term in Standard No. 120 is somewhat broader than your interpretation of the term.; Section S4 of Standard No. 120 contains the following definition 'Weather side' means the surface area of the rim not covered by the inflated tire. The interpretation you offered in your letter was consistent with this definition, because it would require that the information not be labeled in an area where it would be obscured by the inflated tire. However, your interpretation would also require that the information not be labeled in an area where it would be obscured by any axle mounting components, and this requirement is not contained in the definition set forth in Standard No. 120. You are free to use your narrower interpretation for your own purposes since it is consistent with the definition in the Standard, but the definition set forth in the Standard would be used to determine whether a rim complies with the requirements of the Standard.; Please feel free to contact me should you have any further questions o need more information on the requirements of Standard No. 120.; Sincerely, Frank Berndt, Chief Counsel |
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ID: aiam1655OpenMr. James H. Thomas, 8 North Queen Street, Griest Building, Lancaster, Pennsylvania 17603; Mr. James H. Thomas 8 North Queen Street Griest Building Lancaster Pennsylvania 17603; Dear Mr. Thomas: This is in reply to your letter of September 27, 1974, requesting ou position regarding the micro-siping of tires. You also request copies of the government brief in *United States* v. *General Tire*.; The NHTSA does not consider the micro-siping process to be prohibite *per se* when applied to new motor vehicle tires subject to either Motor Vehicle Safety Standard No. 109, 49 CFR S571.109 (applicable to passenger car tires), or Motor Vehicle Safety Standard No. 119, 49 CFR S571.119 (applicable to tires for vehicles other than passenger cars). In the *General Tire* case, the particular tires involved havebeen(sic) micro-siped and were found to have failed certain laboratory wheel tests specified in Standard No. 109. The only issue in the case was General's responsibility for the failure and not whether the tires met the standard. General chose to stipulate that they did not.; The agency has no data on whether micro-siping adversely affects tire's ability to conform to the standards. It is possible that the quality of micro-siping may cause compliance problems. In any event, the agency does not consider micro-siped tires to fail to conform to either standard, unless there is an actual failure to meet the performance tests of the standards.; I have enclosed a copy of the government's brief in the Court o Appeals in the *General Tire* matter. There are other briefs in this litigation, but the agency's position is set forth in this brief and it should be satisfactory for your purposes.; We are pleased to be of assistance. Yours truly, Richard B. Dyson, Acting Chief Counsel |
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ID: aiam1481OpenMr. William J. Cicero, Supt. of Maintenance, Triboro Coach Corporation, 85-01 24th Avenue, Jackson Heights, NY 11369; Mr. William J. Cicero Supt. of Maintenance Triboro Coach Corporation 85-01 24th Avenue Jackson Heights NY 11369; Dear Mr. Cicero: This is in reply to your letter of April 4, 1974, concerning you request for an exemption from the roof emergency exit requirements (S5.2.1) of Motor Vehicle Safety Standard No. 217 (49 CFR 571.217). We had denied an earlier request on March 27, 1974 following your letter to us of February 13, 1974.; We must again deny your request. The Federal motor vehicle safet standards which apply to motor vehicles (some apply to equipment only) specify safety requirements which apply to vehicle types generally (passenger cars, trucks, buses, etc.) and must of necessity be based on the use to which such vehicle types are generally put. The NHTSA has determined through the administrative rulemaking process that buses, including buses for use in urban environments, must have a roof emergency exit when a rear exit can not be installed due to the configuration of the bus. In most cases, including many urban situations, the roof exit can be an important safety feature, particularly when the bus is overturned on a side. While we do not dispute the facts you present, we view the situation as unusual, and not a suitable basis for modifying a requirement applicable to every urban bus. Our regulations do not permit exemptions from requirements for buses sold to one party.; However, under the National Traffic and Motor Vehicle Safety Act (1 U.S.C. SS1391 *et seq.*) under which Standard No. 217 is issued, a vehicle need not conform to a Federal motor vehicle safety standard after its sale to its ultimate user. Consequently there is no Federal prohibition to your modifying or eliminating the roof exits in these buses if you wish, after you receive them from the manufacturer.; Sincerely, Robert L. Carter, Associate Administrator, Motor Vehicl Programs; |
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.