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: aiam4198OpenMr. John C. Hilliard, Chairman & Techncial (sic) Director, Combustion and Fuel Research, Inc., 847-9 South Wagner Road, Ann Arbor, MI 48103; Mr. John C. Hilliard Chairman & Techncial (sic) Director Combustion and Fuel Research Inc. 847-9 South Wagner Road Ann Arbor MI 48103; Dear Mr. Hilliard: Thank you for your letter of July 1, 1986, asking how our regulation would affect the placement of the steering wheel on delivery vehicles. You asked whether there are any State or Federal regulations which would prevent the installation of a right hand drive steering wheel. As discussed below, the National Highway Traffic Safety Administration (NHTSA) has not issued any safety standards that would prohibit the installation of a right hand drive steering wheel. As to State laws, I suggest you check with the Department of Transportation in the States where your client wants to use the vehicles.; Some background information about our agency and its standards may b of assistance to you. NHTSA has the authority to issue safety standards applicable to new motor vehicles and certain items of motor vehicle equipment. NHTSA, however, does not approve motor vehicles or motor vehicle equipment, nor do we endorse any commercial products. Instead, the National Traffic and Motor Vehicle Safety Act establishes a 'self-certification' process under which each manufacturer is responsible for certifying that its products meet our safety standards. The agency periodically tests vehicles and equipment items for compliance with the standards, and also investigates alleged safety-related defects.; We do not have any standards that prohibit the use of a right han drive steering system. We have, however, issued two safety standards (Standard Nos. 203 and 204) that set performance requirements which apply to any steering system, whether left or right hand drive, installed in new passenger cars and light trucks, buses, and multipurpose passenger vehicles. A copy of each of these standards is enclosed.; If you have any further questions, please let me know. Sincerely, Erika Z. Jones, Chief Counsel |
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ID: aiam1660OpenMr. Stanley C. Frye, Product Engineer-Advanced Design, The Flxible Company, Loudonville, OH 44842; Mr. Stanley C. Frye Product Engineer-Advanced Design The Flxible Company Loudonville OH 44842; Dear Mr. Frye: This responds to Flxible's October 11, 1974, petition to exempt th 'trackless trolley coach' category of bus from the requirements of Standard No. 121, *Air brake systems*. You describe the vehicle as similar to your diesel bus but without the weight of the diesel engine, and with electrodynamic braking provided by the traction motor to a maximum of 2.0 mph per second in conjunction with brake operation.; I have enclosed a copy of our letter to Flyer Industries Limited on th same subject. The letter describes our position with regard to status of the trackless trolley as a motor vehicle, and also how it must be tested under Standard No. 121.; You have noted several difficulties in testing a vehicle which use overhead electric lines as a source of power. I would like to point out that, as we interpret the National Traffic and Motor Vehicle Safety Act of 1966, we have established the policy that a manufacturer may conduct certification testing in any manner it chooses, as long as it is calculated, in the exercise of due care, to demonstrate that the vehicle would pass if tested as specified in the standard. Thus, you would be free to certify the vehicle based on tests without use of overhead lines and the benefit of electrodynamic braking. We understand from your letter that without the weight of the diesel engine the trackless trolley has better braking performance than the equivalent diesel engine.; At this time we have issued a proposal that would establish specia test conditions for certain vehicles and limited exemptions for other vehicles, based on their configuration. We will consider your letter as a petition under this rulemaking action, and we invite you to make further comments to Docket 74-10, Notice 7, within the next 30 days.; We will advise you of our determination by letter or by notice in th *Federal Register*.; Yours truly, Richard B. Dyson, Acting Chief Counsel |
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ID: aiam0358OpenMr. Armand F. Macmanus, Phillips Petroleum Company, Bartlesville, Oklahoma 74003; Mr. Armand F. Macmanus Phillips Petroleum Company Bartlesville Oklahoma 74003; Dear Mr. Macmanus: This is in reply to your letter of May 11, 1971, in which you reques an opinion on whether certain tires manufactured by Phillips Petroleum Company are subject to the requirements governing tires that have been issued pursuant to the National Traffic and Motor Vehicle Safety Act (15 U.S.C. S1391 *et seq*). You state that the tires in question result from Phillips' efforts to develop improved tread rubber, and are manufactured by purchasing new tires, buffering them down, and then retreading the remaining casings with experimental tread rubber compounds. You state further that after the casings have been retreaded, the tread rubber compounds are evaluated by stationary wheel testing, road testing, or both, and indicate that some of the road testing takes place on the public highways.; We agree with your conclusion that these tires are not retreade pneumatic tires under Motor Vehicle Safety Standard No. 117, because they are not manufactured from used tires. However, in our view these tires are new pneumatic tires, and accordingly are subject to the requirements of Motor Vehicle Safety Standard No. 109.; Section 108(a)(1) of the National Traffic and Motor Vehicle Safety Ac (15 U.S.C. S1397(a)(1)) provides that no person shall; >>>'manufacture for sale, sell, offer for sale, or introduce or delive for introduction in interstate commerce any motor vehicle or item of motor vehicle equipment manufactured on or after the date any applicable Federal motor vehicle safety standard take effect... unless it is in conformity with such standard.'<<<; Phillips' use of the public roads for testing these tires is a introduction of them in interstate commerce and is prohibited by section 108(a)(1) if the tires do not conform to Standard No. 109.; One objective of the Act that you did not mention in your letter is th prevention of possibly hazardous motor vehicles or motor vehicle equipment from being used on the public highways, where they may endanger not only the driver of the vehicle in question, but other users of the highway as well. The tires need not be manufactured for sale to the general public in order for a violationoof(sic) section 108(a)(1) to occur.; However, if the testing of these tires is confined to the laboratory o to private roads, the prohibition of the Act will not apply to them.; I trust this answers your question.If you have further questions Please write.; Sincerely,Lawrence R. Schneider, Acting Chief Counsel |
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ID: aiam2365OpenMr. W.G. Milby, Staff Engineer, Blue Bird Body Company, P.O. Box 937, Fort Valley, GA 31030; Mr. W.G. Milby Staff Engineer Blue Bird Body Company P.O. Box 937 Fort Valley GA 31030; Dear Mr. Milby: This responds to Blue Bird Body Company's June 21, 1976, questio whether S5.3.1 of Standard No. 121, *Air Brake Systems*, requires the installation of an antilock system, or whether the stopping distance and 'no lockup' requirements may be met using modulation of the service brake control by the vehicle driver.; Section S5.3.1 requires that vehicles subject to it must be capable o stopping under specified conditions, within the stopping distance set forth in Table II without leaving a 12- foot-lane and without 'uncontrolled' lockup of certain wheels of the vehicle. There is no requirement for the installation of an antilock system. Also, there is no test condition that specifies a full brake application and modulation of the service brake may be used to reduce or eliminate lockup.; Yours truly, Frank Berndt, Acting Chief Counsel |
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ID: aiam0708OpenWilliam J. Henrick, Esq., The General Tire & Rubber Company, One General Street, P.O. Box 951, Akron, Ohio 44309; William J. Henrick Esq. The General Tire & Rubber Company One General Street P.O. Box 951 Akron Ohio 44309; Dear Mr. Henrick: #In response to your letter of May 1, 1972, we woul consider a tire with a cord carcass angle of 85 degrees to be within the definition of 'radial ply tire' as that term is defined in Motor Vehicle Safety Standard No. 109. #Sincerely, Richard B. Dyson; |
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ID: aiam2735OpenMr. Donald P. Weiher, AM General Corporation, 32500 Van Born Road, Wayne, MI 48184; Mr. Donald P. Weiher AM General Corporation 32500 Van Born Road Wayne MI 48184; Dear Mr. Weiher: This responds to your December 12, 1977, request for confirmation tha an air-braked electric trackless trolley may be tested for compliance with S5.3.1 of Standard No. 121, *Air Brake Systems*, with its transmission selector control in the 'DRIVE' position if the drive wheels and motor are permanantly (sic) mechanically connected and the motor automatically provides retardation when the service brake control is depressed. Your other requests for interpretation have been answered by separate letters.; Section S6.1.3 of Standard No. 121 specifies: S6.1.3 Unless otherwise specified, the transmission selector control i in neutral or the clutch is disengaged during all decelerations and during static parking brake tests.; This test condition does not permit testing for compliance with th transmission selector control in the 'DRIVE' position. The performance levels of the standard were established at levels intended for the foundation brakes alone, exclusive of engine braking, and it is for this reason that the selector must be in neutral or the clutch disengaged. This is true both for vehicles with manual and automatic transmissions.; It does appear that a case may be made for testing the bus you describ with the selector in 'DRIVE'. One important factor would be whether the field in the motor generator is permanent or electrically induced. In the event you wish to petition for an amendment of S6.3.1, information of this nature should accompany your petition.; In response to your other question, the agency's July 10, letter t Flyer Industries remains valid.; Sincerely, Joseph J. Levin, Jr., Chief Counsel |
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ID: aiam3827OpenMr. Takeshi Tanuma, Chief Operating Office, Nissan Research & Development, Inc., P.O. Box 8650, Ann Arbor, MI 48104; Mr. Takeshi Tanuma Chief Operating Office Nissan Research & Development Inc. P.O. Box 8650 Ann Arbor MI 48104; Dear Mr. Tanuma: This responds to your April 4, 1984 letter regarding the use of tw certification labels on motor vehicles, with each label containing a portion of the information specified in 49 CFR Part 567 and the two labels together providing all the specified information.; While the certification regulations specify that 'a label' shall b used, the agency has permitted the use of a label in two parts in circumstances which will not lead to confusion and which will satisfy the basic intent of Part 567. In particular, the two portions of the label must be placed in close proximity to each other, to permit individuals to readily find all the specified information and to leave no doubt as to the significance of either portion of the label. Further, the two portions must be oriented in such a manner that the information specified in section 567.4(g) of the certification regulations appears in the required order. As a practical matter, these considerations require that the two portions be affixed to the same vehicle part. While we cannot specify a particular distance as a maximum permissible separation of the two portions of the label, the two portions must be located so as to leave the unmistakable impression that they provide related information.; You also raised the possibility of adding language to one portion o the label to indicate the existence of the other portion and to specify the location of the second portion. While such language is not required, it might be a desirable means of promoting compliance with the considerations discussed above.; Sincerely, Frank Berndt, Chief Counsel |
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ID: aiam3574OpenJames Marshall Smith, Esq., Legal Aid of Western Missouri, 1103 Grand Avenue, Kansas City, MO 64106; James Marshall Smith Esq. Legal Aid of Western Missouri 1103 Grand Avenue Kansas City MO 64106; Dear Mr. Smith: This is in response to your letter of June 10, 1982, concerning whethe the odometer disclosure statement on the Missouri certificate of title has been approved for use in lieu of the Federal odometer disclosure statement.; The Motor Vehicle Information and Cost Savings Act ('Act') (15 U.S.C S1981 *et seq*.) prohibits the disconnection, resetting or alteration of a vehicle odometer with the intent to change the number of miles. The Act also requires that a written disclosure of the mileage registered on the odometer be provided by the seller to the buyer at the time ownership of a vehicle is transferred. 15 U.S.C. S1988. Each dealer or distributor of a motor vehicle is required by law to retain for four years a copy of each odometer statement he issues and receives. Odometer Disclosure Requirements ('regulations') (49 CFR Part 580).; The Odometer Disclosure Requirements provide that the transferor of vehicle may make the disclosure required by the Federal odometer laws on the state certificate of title, if the state title document contains essentially the same information required on the Federal odometer disclosure statement. If the information contained on the state certificate of title varies from that required by the Federal form, the state must obtain the approval of this agency before its certificate of title can be used as a substitute for the Federal form.; In order to spare states the burden of an approval process the agenc has indicated that certain variations from the Federal form are acceptable. In the *Federal Register* notice of August 1, 1977, which amended the disclosure regulation, we gave examples of shortened forms that would be acceptable.; A state document can be considered to be approved for use as a ful disclosure statement if it varies from the Federal form in only those aspects noted in the August 1, 1977, notice, a copy of which is enclosed.; Missouri has not submitted its certificate of title to the agency fo approval as a substitute for the Federal odometer disclosure statement so, therefore, the agency does not know whether Missouri's certificate of title can be substituted for the Federal odometer disclosure statement.; If you have any further questions, please do not hesitate to write. Sincerely, David W. Allen, Assistant Chief Counsel |
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ID: aiam1549OpenMr. M.A. Chermak,Imperial-Eastman Corporation,Eastman Division,14-40 North 24th Street,Manitowoc, Wisconsin 54220; Mr. M.A. Chermak Imperial-Eastman Corporation Eastman Division 14-40 North 24th Street Manitowoc Wisconsin 54220; Dear Mr. Chermak:#This responds to your June 24, 1974, question whethe brake hose manufactured before September 1, 1974, to comply with all performance requirements of Standard No. 106-74, *Brake hoses*, may be marked with the DOT symbol after that date, and whether the DOT may be used on hose, fittings, and assemblies prior to that date.#The answer to your questions is no. The DOT symbol means that a vehicle or item of motor vehicle equipment was manufactured in compliance with a Federal motor vehicle safety standard and that it complies with the standard. Therefore, the DOT symbol can not be placed on hose, fitting or assemblies manufactured before the date the standard becomes applicable to them, whether or not the DOT is actually placed on the hose before or after the effective date.#With regard to your supply of pre-106 vacuum hose, it may be used in assemblies as late as February 28, 1975, and in vehicles as late as August 31,1975, if it is only clamped to the vehicle and not made into assemblies.#Yours truly,Richard B. Dyson,Assistant Chief Counsel; |
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ID: aiam3124OpenMr. Thomas F. Brown, Executive Engineer, Vehicle Regulations and Standards, Engineering Division, Mack Trucks, Inc., P.O. Box 1761, Allentown, PA 18105; Mr. Thomas F. Brown Executive Engineer Vehicle Regulations and Standards Engineering Division Mack Trucks Inc. P.O. Box 1761 Allentown PA 18105; Dear Mr. Brown:#I regret the delay in responding to your letter of Jul 19, 1979, which requested an interpretation of Federal Motor Vehicle Safety Standard 101-80, *Controls and Displays*. You asked whether placing the turn signal symbol on the turn signal control shown in your illustration so that the arrows are vertical would comply with the standard.#The answer is no. Section 5.2.1 of the standard requires that the turn signal symbol appear perceptually upright to the driver. The purpose of that requirement is to ensure quick and accurate indentification (sic) of the vehicle controls. The upright position of a symbol is determined by referring to column 3 of Table 1 of Safety Standard 101-80. That table shows that the upright position for the turn signal symbol is with the arrows pointing horizontally. Thus, the arrows must point essentially horizontally in the motor vehicle.#Since the symbols required by Safety Standard 101-80 were selected in order to facilitate international standardization and harmonization, it is important that they not be significantly altered from one vehicle to another. This is particularly important in order to ensure that drivers become familiar with the meaning of various symbols including the turn signal symbol.#However. Safety Standard 101-80 does permit manufacturers to supplement the symbols designated in Table 1 of the standard with additional words or symbols for the purpose of clarity. Therefore, nothing in the standard would prevent your company from adding additional symbols, such as curved thinner arrows next to the turn signal symbol, to indicate mode of operation.#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.