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 |
|---|---|
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 |
|
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; |
|
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 |
|
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 |
|
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 |
|
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; |
|
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; |
|
ID: aiam1119OpenMr. Norman E. Salzman, General Manager, The Fairmount Press, 1993 Jerome Avenue, Bronx, NY 10453; Mr. Norman E. Salzman General Manager The Fairmount Press 1993 Jerome Avenue Bronx NY 10453; Dear Mr. Salzman: This is in response to your request for a review of Fairmount Pres forms MFV, ABW, and WH for their conformity with the odometer disclosure requirements of the Motor Vehicle Information and Cost Savings Act.; Form MFV conforms to the requirements, although it appears from th wording of the disclosure that there may be a misunderstanding as to when the disclosure must be given. Your form contains the statement that 'The mileage appearing on the odometer of the motor vehicle described above *at time of transfer* to * was* as follows:' The intent of the regulation is to make disclosure before the transfer, and the MFV form should therefore be executed before transfer, notwithstanding the quoted language.; Form ABW incorporates the disclosure in the bill of sale, as permitte by the regulations. However, the statement is deficient because there is no provision for (1) last plate number, (2) body style, (3) model, and (4) a check-off provision in the situation where the transferor knows the indicated mileage is incorrect.; Form WH is similarly deficient in that there is no provision for (1 body style, (2) last plate number, and (3) a check-off provision in the situation where the transferor knows the indicated mileage is incorrect.; Yours truly, Richard B. Dyson, Assistant Chief Counsel |
|
ID: aiam3431OpenMr. C. L. Biddle, Supervisor of Claims, General Transportation Department, Firestone Tire Company, 1200 Firestone Parkway, Akron, Ohio 44317; Mr. C. L. Biddle Supervisor of Claims General Transportation Department Firestone Tire Company 1200 Firestone Parkway Akron Ohio 44317; Dear Mr. Biddle: This responds to your recent letter to Mr. Kratzke of my staff describing a situation in which a railroad car full of new tires caught on fire. As a result of the damage caused to the tires by the fire, Firestone's quality control staff determined that the tires could no longer be certified as safe for highway use. The railroad company has refused to pay your claim for damage to the tires unless Firestone releases the damaged tires to the railroad company. You stated that the railroad company will either sell the tires through its salvage outlets or use the tires on company vehicles. You ask whether you can rightfully withhold these tires from the railroad company.; If Firestone releases the tires and the railroad company sell the tire or uses them on the public roads, both Firestone and the railroad company would violate an express provision of the National Traffic and Motor Vehicle Safety Act of 1966, as amended (15 U.S.C. 1381 *et seq.*) ('the Safety Act'). Therefore, you can rightfully withhold the tires from the railroad company.; Your letter did not indicate whether the damaged tires were tires fo passenger cars or tires for motor vehicles other than passenger cars. In either case, the tire manufacturer is required to certify that each tire fully complies with certain marking requirements and with specified performance requirements (resistance to bead unseating, strength, endurance, and high speed performance) of Safety Standard No. 109 in the case of passenger car tires (49 CFR S571.109) or of Safety Standard No. 119 for tires other than passenger car tires (49 CFR S571.119). This certification is made by the manufacturer by molding the letters 'DOT' into the sidewall of the tire.; As a result of the damage to this particular shipment of tires, you company has determined that this certification is no longer valid. This determination obligates Firestone to remove the 'DOT symbol from the sidewall of the tires.; Without the 'DOT' symbol, these tires would clearly not comply with th requirements of either Standard No. 109 or Standard No. 119. Section 108(a)(1)(A) of the Safety Act (15 U.S.C. 1397(a)(1)(A)). provides:; >>>No person shall manufacture for sale, sell, or offer for sale, o introduce or deliver for introduction in interstate commerce, or import into the United State, any ... item of motor vehicle equipment manufactured on or after the date any applicable Federal motor vehicle safety standard takes effect under this title unless it is in conformity with such standard...<<<; Firestone would violate this prohibition if it were to deliver tires t the railroad company which were not certified as complying with the appropriate safety standard. The railroad company would violate this prohibition if it sold or offered to sell uncertified tires, or if uncertified tires were used by the company on the public roads (introduction in interstate commerce). Section 109 of the Safety Act (15 U.S.C. 1398) specifies penalties of up to $1000 for each violation of section 108. Section 109 specifies that the maximum civil penalty which can be imposed for a series of related violations, which this would be, is $800,000 for each violator.; You indicated that Firestone would not release the damaged tires fo use in any case, because of the potential safety hazard. I hope that this response reinforces that position. Should you need any further information on this matter, please do not hesitate to contact me. Please show this letter to the interested railroad company so that it will realize the serious nature of its contemplated actions.; Sincerely, Frank Berndt, Chief Counsel |
|
ID: aiam3061OpenHonorable Mark Marks, 108 Federal Court House, Erie, Pennsylvania 16501; Honorable Mark Marks 108 Federal Court House Erie Pennsylvania 16501; In response to the request of Ms. Chris Anderson of your office, I hav enclosed a copy of a letter which I recently wrote detailing the National Highway Traffic Safety Administration (NHTSA) regulations pertinent to the manufacture of trailers. Please note the reference on page 2 of the letter concerning the 'Manufacturer Identification' requirements. These requirements are independent of those pertinent to the Vehicle Identification Numbers.; Under current regulations (49 CFR Part 571.115), manufacturers o trailers are not subject to the Vehicle Identification Number requirements. However, pursuant to recent amendments (see enclosed copy), a manufacturer of trailers will be required to affix a Vehicle Identification Number to every Trailer manufactured on or after September 1, 1980. Although, the Vehicle Identification Number will not have to be affixed until this date, certain reports will be required in advance. Any trailer manufacturer who begins production before September 1, 1979, must report to NHTSA by that date the characters that he will include in his Vehicle Identification Numbers to uniquely identify himself, the make and the type of vehicle he produces. A manufacturer beginning production after September 1, 1979, must submit this information at least 60 days before he begins affixing the Vehicle Identification Numbers to vehicles.; I hope that this information will be helpful to you and you constituent. I will be happy to answer any further questions that you may have.; Sincerely, Frank Berndt, 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.