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: aiam3418OpenMr. John Y Yonezawa, Tokai Rubber Industries, Ltd., 3600, Kita Toyama, Komaki City, Aichi Pref. 485, Japan; Mr. John Y Yonezawa Tokai Rubber Industries Ltd. 3600 Kita Toyama Komaki City Aichi Pref. 485 Japan; Dear Mr. Yonezawa: This responds to your recent letter regarding several new kinds o plastic vacuum brake hoses that you plan to manufacture. The plastic brake hoses are flexible nylon tubes for use in a vacuum braking system. You indicate that these hoses cannot comply with several provision of Safety Standard No. 106, and ask whether the plastic hoses could qualify as 'vacuum tubing connectors.'; Safety Standard No. 106 (49 CFR 571.106) specifies performance an labeling requirements for brake hose, which is defined in the standard as:; >>>a flexible conduit, other than a vacuum tubing connector manufactured for use in a brake system to transmit or contain the fluid pressure or vacuum used to apply force to a vehicle's brakes.'<<<; Since the nylon tubes which you plan to manufacture will transmit th vacuum used to apply force to a vehicle's brakes, the tubes would qualify as 'brake hose' under this definition and would be subject to all requirements of Safety Standard No. 106. Moreover, it appears that the nylon tubes would not qualify as 'vacuum tubing connectors,' which are excepted from compliance with the standard in the definition of brake hose. Section 4 of Safety Standard No. 106 defines 'vacuum tubing connector' as:; >>>a flexible conduit of vacuum that (i) connects metal tubing to meta tubing in a brake system, (ii) is attached without end fittings, and (iii) when installed, has an unsupported length less than the total length of those portions that cover the metal tubing.'<<<; According to the illustrated drawings included in your letter, th nylon flexible tubes with which you are concerned would have an unsupported length which is greater than the total length of those portions that cover metal tubing. Therefore, the nylon tubes would not qualify as 'vacuum tubing connectors' under subsection (iii) of the above definition. The purpose of the definition is to except from compliance with the standard only those vacuum connectors that have unsupported lengths short enough that they will not sag or deflect because of their own weight. While your nylon tubes may be sturdy enough to meet this intended purpose, as the definition is currently written, the tubes cannot be considered vacuum tubing connectors.; If, as your letter indicates, the nylon brake hose does not comply wit all requirements of Safety Standard No. 106, you would not be permitted to sell it in the United States. You may wish to petition the agency to amend Standard No. 106 to establish separate performance requirements specifically designed for nylon vacuum tubing such as that produced by Tokai. I am enclosing a copy of the procedures which explain how you can file a petition, in case you are interested.; Sincerely, Frank Berndt, Chief Counsel |
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ID: aiam4627OpenMr. L.T. Mitchell, Specification Engineer Thomas Built Buses, Inc. P.O. Box 2450 1408 Courtesy Road High Point, N.C. 27261; Mr. L.T. Mitchell Specification Engineer Thomas Built Buses Inc. P.O. Box 2450 1408 Courtesy Road High Point N.C. 27261; "Dear Mr. Mitchell: This responds to your letter asking us to reasses our previous interpretations of Standard No. 217, Bus Window Retention and Release (49 CFR /571.217). Before turning to the substance of your letter, I would like to apologize for the regrettable delay in this response. You asked us to reassess a December 20, 1984 letter to Mr. Melvin Smith regarding school buses. Mr. Smith had, among other things, asked for an interpretation of the concluding sentence of S5.4.2.1(b) of Standard No. 217. Section S5.4.2.1(b) requires side emergency doors installed in a school bus with a gross vehicle weight rating of more than 10,000 pounds to have an opening that is at least 45 inches high and 24 inches wide when the side door is extended. The final sentence of S5.4.2.1(b) reads: 'A vertical transverse plane tangent to the rear-most point of a seat back shall pass through the forward edge of a side emergency door.' Mr. Smith had asked how much, if any, forward and/or rearward variation from perfect coincidence of the plane and door edge were permissible. We responded that no variation from the explicit requirements of the standard is permissible. Your letter stated that a requirement for an exact coincidence of the plane and door edge 'opens the door to impossible manufacturing requirements,' and is 'an extremely difficult goal to meet.' You stated that requiring an exact relationship between a part of the seat and the door will require multiple seat installation adjustments, bending the seat, or deforming the seat padding. To avoid such burdens, you asked if the agency would consider setting tolerances for the coincidence of the points expressed in this provision. You proposed the following interpretation of the requirement for coincidence of the plane and door edge: 1. A seat back may not intrude backward into the door opening through the transverse plane coincident with the leading edge of the door opening. 2. A seat back may be located ahead of this transverse plane by no more than three-quarters of an inch, plus or minus three-quarters of an inch, or within but no more than, one and one-half inches ahead of the transverse plane coincident with the leading edge of the door opening. It would be helpful to set forth some background information to fully explain why NHTSA cannot issue an intepretation along the lines you have suggested. Section 103 of the National Traffic and Motor Vehicle Safety Act (15 U.S.C. 1392, the Safety Act) specifies that NHTSA shall establish by order appropriate safety standards and that the Administrative Procedure Act shall apply to all orders establishing, amending, or revoking a safety standard. The Administrative Procedure Act generally requires agencies to publish a notice setting forth the proposed change to a safety standard, and allow the public to comment thereon, before the agency can adopt any change to the established safety standard. Please note that the Safety Act requires public notice and comment only when adopting orders that establish, amend, or revoke a safety standard. Interpretations are not subject to the requirements for public notice and comment, because interpretations do not add, delete, or change any requirements established in a safety standard. Instead, intepretations explain how the requirements established in safety standards or the Safety Act apply to particular vehicles or equipment, or otherwise clarify the meaning of the established requirements. In this case, the meaning of the requirement in Standard No. 217 that 'a vertical transverse plane tangent to the rear-most point of a seat back shall pass through the forward edge of a side emergency door' is clear. This language clearly and unequivocally requires an exact coincidence of the location of the seat back and the forward edge of a side emergency door. There is no way that we can interpret this language in accordance with your suggestion, i.e., that the seat back shall be located no more than 1 and 1/2 inches forward of the forward edge of the emergency door. Your letter suggested a change to the requirements of Standard No. 217, not a clarification of those requirements. As explained above, the only way by which we can change those requirements is to initiate rulemaking and give the public notice of and the opportunity to comment on the proposed change. Hence, your letter asking for an interpretation would have been more properly filed as a petition for rulemaking, pursuant to the provisions of 49 CFR Part 552. Ordinarily, we would simply notify you of your right to file such a petition and take no further action unless and until you decided to file such a petition. In this case, however, the delay in this response may have conveyed the erroneous impression that NHTSA would provide a substantive response to your request in this interpretation. To ensure that your request receives a response addressing its merits, we will treat your letter as a petition for rulemaking filed under Part 552. We will notify you of our response to the petition as soon as we have completed our review of it. Sincerely, Stephen P. Wood Acting Chief Counsel"; |
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ID: aiam4430OpenRobert L. Ripley, President Knaack Manufacturing Co. 420 East Terra Cotta Avenue Crystal Lake, IL 60014; Robert L. Ripley President Knaack Manufacturing Co. 420 East Terra Cotta Avenue Crystal Lake IL 60014; Dear Mr. Ripley: This is a response to your letter asking this agenc to review three product catalogs you submitted with your letter, and tell you whether your company is required to furnish information pursuant to 49 CFR Part 566, Manufacturer Identification. Based on the information you supplied with your letter, your company is required to file information under Part 566 for the warning devices shown in one of the catalogs, but not for any of the other items shown in the three catalogs. As specified in the Application section of Part 566 (/566.3), Part 566 applies to (1) all manufacturers of motor vehicles and (2) manufacturers of motor vehicle equipment, other than tires, to which a safety standard applies. The only item advertised in the three catalogs that is motor vehicle equipment to which a safety standard applies is the 'Safety Reflector Kit' shown on page 6 of the catalog entitled 'weather guard For Full-Size and Mini Vans.' These devices are subject to Standard 125, Warning Devices (49 CFR /571.125). Accordingly, your company, as the manufacturer of these devices, must furnish the information specified in /566.5 within the time period specified in /566.6. I hope you find this information helpful. If you have further questions, please contact Joan F. Tilghman of my staff at (202) 366-2992. Sincerely, Erika Z. Jones Chief Counsel; |
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ID: aiam1632OpenMr. Zenjiro Hase,Toyoda Gosei Co., Ltd.,9, 1-chome, Nishiyabushitacho,Nishiku, Nagoya, Japan; Mr. Zenjiro Hase Toyoda Gosei Co. Ltd. 9 1-chome Nishiyabushitacho Nishiku Nagoya Japan; Dear Mr. Hase:#I would like to clarify our letter to you of August 21 1974, concerning the use of bands on brake hose assemblies before and after March 1, 1975. I have enclosed copies of your to us and our response.#When our letter stated that we agreed with your interpretation, we did not intend to say that it is permissible to place the label band on brake hose assemblies prior to March 1, 1975. The use of the DOT symbol on these assemblies would constitute a false and misleading certification in violation of S108(a) (3) of the National Traffic and Motor Vehicle Safety Act of 1966 (15 U.S.C. S1397(a) (3)). This is because the DOT label would suggest compliance with regulations which are not yet effective.#In the event that our August 21, 1974, letter caused your company to manufacture any assemblies with bands, please contact me as soon as possible.#Yours truly,Richard B. Dyson,Acting Chief Counsel; |
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ID: aiam0920OpenMr. R. B. Smith, Finance Manager, Bluefield Mack Trucks, Inc., 536 Bluefield Avenue, Bluefield, West VA 2470l; Mr. R. B. Smith Finance Manager Bluefield Mack Trucks Inc. 536 Bluefield Avenue Bluefield West VA 2470l; Mr. R. B. Smith: This is in reply to your letter of November 17, 1972, requestin information on alteration, and installation of fifth wheels, on new trucks.; Persons who install fifth wheels on new trucks are generally considere to be 'final-stage manufacturers' under NHTSA Certification regulations, and are required to certify that vehicles on which they install the fifth wheel conform to applicable Federal standards. The NHTSA has recently proposed requirements regarding persons who alter completed vehicles, and a copy of this proposal is enclosed.; Copies of NHTSA requirements maybe obtained as indicated on th enclosure, 'Where to Obtain Motor Vehicle Safety Standards and Regulations.' The regulations regarding the certification of motor vehicles are found at Parts 567 and 568 of Title 49 of the Code of Federal Regulations, (Item 1) and of the volume, 'Federal Motor Vehicle Safety Standards and Regulations' (Item 3).; Yours truly, Richard B. Dyson, Assistant Chief Counsel |
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ID: aiam4060OpenMr. Russ L. Bomhoff, Special Projects Director, Precision Pattern Inc., 1643 S. Maize Road, Wichita, KS 67209; Mr. Russ L. Bomhoff Special Projects Director Precision Pattern Inc. 1643 S. Maize Road Wichita KS 67209; Dear Mr. Bomhoff: Thank you for your letter of October 30, 1985, asking about the effec of our regulations on several components you wish to install in the interior of a passenger car. I hope the following discussion answers your questions.; All new vehicles manufactured for sale in the United States must b certified by their manufacturer as complying with the Federal motor vehicle safety standards. If you are installing the components described in your letter in a new vehicle prior to its first sale to a consumer, then you would be considered a vehicle alterer. Under our certification regulation (49 CFR Part 567), a vehicle alterer must certify that the vehicle as altered continues to comply with all applicable Federal motor vehicle safety standards. Since you are modifying the interior of the passenger car, you must ensure that the vehicle will still comply with Standard No. 201, *Occupant Protection in Interior Impact*, a copy of which is enclosed.; If you are making these alterations to a used vehicle, then you, as commercial business, would be covered by section 108(a)(2)(A) of the National Traffic and Motor Vehicle Safety Act. That section prohibits manufacturers, dealers, distributors, and motor vehicle repair shops from knowingly rendering inoperative any element of design installed on a vehicle in compliance with Federal safety standards. Thus, in installing the components you described, you cannot render inoperative the vehicle's compliance with Standard No. 201 or any of our other standards.; The potential effect of Standard No. 201 on each of the components yo asked about is discussed below.; *Front and rear seat cooler consoles*. S3.1 of the standard sets performance requirements for the instrumen panel. S3.1.1(a) of the standard specifically provides that the instrument panel requirements do not apply to console assemblies. We would consider both the front and rear seat coolers to be console assemblies and thus exempt from the requirements of S3.1.; S3.3 of the standard requires interior compartment door assemblie located in an instrument panel, a console assembly, a seat back, or a side panel adjacent to a designated seating position to remain closed under certain test conditions. The purpose of the requirement is to prevent a door from flying open and striking an occupant in a crash. The doors in the front and rear consoles would have to meet this requirement.; *Seat back fold-down tables*. S3.2 of the standard sets performance requirements to limit injurie caused when rear seat occupants strike the seat backs in front of them. You would have to ensure that the seat backs would still comply with S3.2 when the fold- down tables are installed.; The fold-down tables mounted in the seat back and the door do not hav to meet the requirement in S3.3 for interior compartment doors. However, since both those items are hinged surfaces which could fly open in a crash and pose a hazard to an occupant in a crash, we urge you to ensure that the tables will be adequately secured in a crash.; S3.5 of the standard sets requirements for armrests. You would have t ensure that the vehicle will still comply with S3.5 when the fold-down table is installed in the door.; *TV/VCR Cabinet* There are no requirements that apply to the TV/VCR cabinet. If you have any further questions, please let me know. Sincerely, Erika Z. Jones, Chief Counsel |
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ID: aiam1798OpenHonorable Warren G. Magnuson, Chairman, Committee on Commerce, United States Senate, Washington, DC 20510; Honorable Warren G. Magnuson Chairman Committee on Commerce United States Senate Washington DC 20510; Dear Mr. Chairman: This is in response to your letter of January 31, 1975, in which yo asked whether the question of a lowering of the bumper impact requirements had been prejudged, and also requested our position on the question of cost-effectiveness of bumper designs.; With respect to your first question, I give you my unqualifie assurance that the question of what bumper impact level should be required has not been prejudged. My mind is certainly still open, and we are examining with keen interest the comments we are receiving on the proposal before any final decision is made. The statement you quoted, that certain factors lead us to believe that the proposed action 'appears to be necessary,' reflects the attitude of tentative judgment that we normally have at the time a proposal is issued. The comments we receive help us to determine whether the 'appearance' of the necessity of an action is realistic.; The problem of obtaining the most cost-effective bumper designs i response to a performance standard is a difficult one. With most standards the problem has not been as significant, because the interest of manufacturers in keeping their costs down generally has coincided with the best interest of the consumer. A bumper that provides significant protection can be such a major weight factor, however, that the cheapest design from a manufacturer's standpoint may not be the least costly to the consumer if lifetime fuel and maintenance costs are figured in.; We are studying the possibility of putting a limit on bumper weight a an explicit requirement of the bumper standard. We have no doubt that the Motor Vehicle Information and Costs Savings Act gives us the legal authority to do this, since weight and the attendant fuel penalty is a major factor in consumer cost. The questions we have at this time involve technology (*e.g.*, how to identify the systems in question so that their weight can be objectively limited without undue design restriction) and policy (*e.g.*, whether weight limitations may lead to new cost-effectiveness problems if manufacturers choose to use exotic materials); I deeply appreciate the interest you have shown in this matter. I a sure our interests coincide: obtaining the greatest net benefits from the bumper systems that consumers buy.; Sincerely, James B. Gregory, Administrator |
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ID: aiam1262OpenHonorable Dewey Bartlett, United States Senate, Washington, DC 20510; Honorable Dewey Bartlett United States Senate Washington DC 20510; Dear Senator Bartlett: This is in reply to your letter of July 23, 1973, forwarding to u correspondence from Mr. G. N. Nichols, President, Midwestern Products, Incorporated, Tulsa, concerning the applicability of Federal regulations to an air suspension auxiliary axle manufactured by Midwestern Products. According to the manufacturer's advertising brochure, this axle, the 'Micro-Air Retractable Safety Axle,' is intended to be used on pick-up and bobtail trucks, particularly in the recreational vehicle and related fields.; There are presently no Federal motor vehicle safety standards o regulations that apply to the manufacture of these axles. However, persons who install them on *new* pick-up trucks or other vehicle types (a 'new' vehicle under the National Traffic and Motor Vehicle Safety Act is one that has not yet been sold to a user) may be considered as vehicle alterers under provisions of NHTSA certification regulations which are to become effective February 1, 1974 (Docket No. 72-27, copy enclosed), and would be required to affix to the vehicle the label described in section 567.7 of those regulations.; Midwestern Products should be aware of these requirements whether i installs the Micro-Air axle or whether the installation is done by other parties. In the former case Midwestern would be responsible for affixing the required label, and in the latter it should provide the relevant information for the label regarding weight ratings to the party making the installation.; The NHTSA does not maintain a mailing list to provide copies of NHTS notices and regulations. Copies are available as indicated on the enclosed sheet, 'Where to Obtain Motor Vehicle Safety Standards and Regulations.'; We are pleased to be of assistance. Sincerely, Robert L. Carter, Associate Administrator, Motor Vehicl Programs; |
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ID: aiam5221OpenMr. Ron Marion Sales Engineer Thomas Built Buses, Inc. P.O. Box 2450 1408 Courtesy Road High Point, N.C. 27261; Mr. Ron Marion Sales Engineer Thomas Built Buses Inc. P.O. Box 2450 1408 Courtesy Road High Point N.C. 27261; "Dear Mr. Marion: This responds to your inquiry about the applicabilit of Standard No. 131, School Bus Pedestrian Safety Devices, to school buses you wish to sell to a customer in the United States Virgin Islands. You stated that these buses will be built as right hand drive vehicles with the entrance door located on the left side, since vehicles are driven on the left side of the road in this jurisdiction. You asked whether you can install, on the right side of the bus, the stop signal arm that is required by FMVSS 131. The answer is yes. The National Traffic and Motor Vehicle Safety Act (15 U.S.C. 1381, 'Safety Act') requires new school buses sold in this country and in the U.S. Virgin Islands to comply with all applicable Federal school bus safety standards. (See, 15 U.S.C. 1391(8) for reference to the Virgin Islands.) Standard No. 131 requires school buses to be equipped with a stop signal arm 'on the left side of the bus.' (S5.4) The purpose of this standard is 'to reduce deaths and injuries by minimizing the likelihood of vehicles passing a stopped school bus and striking pedestrians in the vicinity of the school bus.' (S2) When NHTSA specified that the stop arm must be placed on 'the left side of the bus,' the agency meant the driver's side. Comments to the notice of proposed rulemaking (NPRM) and preamble of NHTSA's final rule all assumed that the left side of the bus meant the driver's side. (56 FR 20363, 20367). For example, while endorsing the proposed requirement for the stop arm, several commenters stated that an arm is needed near the driver's window. Moreover, S5.4.1(b) states that, for locating the arm, 'the top edge of the stop signal arm is parallel to and not more than 6 inches from a horizontal plane tangent to the lower edge of the frame of the passenger window immediately behind the driver's window.' (Emphasis added). This provision indicates that the agency assumed that the 'left' side is the driver's side. Further, a stop arm would not be needed on the non-traffic side of the vehicle. Since the left side is not the driver's side for the school buses in question, the agency's general assumption was incorrect. In light of your letter, we will issue a technical amendment of Standard 131 so that S5.4 will require the stop signal arm on the driver's side of the bus. Until the amendment is issued, we will not take enforcement action regarding a manufacturer's locating a right hand drive school bus with a stop signal arm on the bus's driver's side. I hope this information is helpful. If you have any questions about NHTSA's safety standards, please feel free to contact Marvin Shaw at this address or by telephone at (202) 366-2992. Sincerely, John Womack Acting Chief Counsel"; |
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ID: aiam0023OpenMr. David Busby, Busby and Rivkin, Counsellors at Law, 815 15th Street, N.W., Washington, DC 20005; Mr. David Busby Busby and Rivkin Counsellors at Law 815 15th Street N.W. Washington DC 20005; Dear Mr. Busby: Thank you for your letter of April 26, 1967, concerning th interpretation of Safety Standard Number 210.; Paragraph S3.1.1 of Standard Number 208, specifies that the Type 2 sea belt anchorage shall be installed in each outboard passenger seat position that includes the windshield header within the head impact area. Therefore, the rear seat is not included in this area and no Type 2 belt assembly is required. A copy of the Federal Register published February 3, 1967, is enclosed for your information.; With regard to your comments on *Standard Number 209* and on th provision of Section 108(b)(3) of the Act, please be advised that we anticipate the promulgation of joint regulations with the Secretary of the Treasury, permitting the importation of vehicles upon appropriate assurance that they will be brought into conformity with all applicable Federal standards prior to sale. These regulations or related regulations will prescribe the proper means of certifying such nonconforming vehicles in order to insure their admission through United States Customs.; Sincerely yours, George C. Nield, Acting Director, Motor Vehicle Safet Performance Service; |
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.