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
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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; |
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ID: aiam0189OpenMr. E. W. Bernitt, Vice President, Safety and Quality Assurance, American Motors Corporation, 14250 Plymouth Road, Detroit, MI 48232; Mr. E. W. Bernitt Vice President Safety and Quality Assurance American Motors Corporation 14250 Plymouth Road Detroit MI 48232; Dear Mr. Bernitt: We have received your submittal of consumer information in response t the requirements of 49 CFR Part 375. That regulation requires that manufacturers submit their information to the Administrator 30 days in advance of the time it is made available to prospective purchasers. Since we have not required that this advance submittal be in the same form as that given to prospective purchasers, the following comments are only advisory in nature. There are several respects, however, in which your information, if supplied in this form to prospective or actual purchasers, would not satisfy the requirements of the regulations.; >>>1. The Stopping Distance information is presented as a 'range o stopping distances,' both in numerical and graphical form. The regulations clearly require a single stopping distance figure to be provided for a given group, that can be met or exceeded by all vehicles in the group. We do not know, and consumers surely would not know, the significance of the lower figure given. Even if it were clear, the provision of such additional, non-required information in close proximity to the required data would cause confusion in attempting to compare figures between various makes--the main purpose of the information.; 2. The provision of four sets of data in respect to partial failure o the braking system, for 'fronts operative' and 'rears operative,' and for lightly-loaded and maximum-loaded vehicles, is not in accordance with the regulation requirement that information be provided for the 'most adverse combination' of weights and system failures. As stated in item 1, above, the inserting of this additional information, self-serving in every case since only the worst element should be included, would make comparisons difficult and be unfair to competing manufacturers who followed the regulations strictly.; 3. The form of the Stopping Distance information would fail to satisf the requirement that the information be presented 'in essentially the form illustrated in Figure 1' of 49 CFR S 375.101. In particular, we refer to the placing of two columns side by side instead of the single-axis graph depicted in that figure, and the inclusion of other verbiage between the required statements and warnings and the information itself. The reference to shorter stopping distances with wheel lock-up and without restricting pedal effort, between the required information and the graphs, is especially objectionable, since the safety advantages of avoiding wheel skid were a particular concern in developing this regulation. Although the regulations do not prohibit the provision of other than required information in a Consumer Information booklet, they do require that it be separated in such a manner that the required information, both textual and quantitative, is presented in 'essentially the form illustrated.'; 4. The Tire Reserve Load section of the regulations requires that 'th table that is provided for a specific vehicle shall contain only information that is applicable to that vehicle.' This requirement prohibits a large, all-purpose chart such as yours, with information for many vehicles included on it, at least as far as the information given to the actual purchaser of a vehicle is concerned. More generally, the information is not presented in 'essentially the form illustrated in Figure 1' of 49 CFR S 375.102.; 5. The large, all-inclusive bar graph on Acceleration and Passin Ability does not present the information in 'essentially the form illustrated in Figure 1' of 49 CFR S 375.106, as required.<<<; We will be glad to answer any questions that you may have with respec to the requirements of these or other motor vehicle safety regulations and standards.; Sincerely, Robert Brenner, Acting Director |
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ID: aiam4963OpenDr. Carl C. Clark Safety Systems Company 23 Seminole Avenue Baltimore, MD 21228-5638; Dr. Carl C. Clark Safety Systems Company 23 Seminole Avenue Baltimore MD 21228-5638; "Dear Dr. Clark: This responds to your request for an interpretation o Standard No. 205, Glazing Materials (49 CFR 571.205). More specifically, your letter indicated your belief that Standard No. 205 permits a prime glazing material manufacturer to designate an item of glass-plastic glazing that it manufactures as 'Item 14' glazing if that glass- plastic glazing item passes all the tests specified for Item 14 glazing. It is your view that it is irrelevant whether the individual glass layers in the glass-plastic glazing are tempered or annealed glass. Your understanding is correct. Standard No. 205 specifies the performance requirements for Item 14 glazing, through a series of 14 tests designated for that item of glass-plastic glazing material. No test applicable to Item 14 glazing specifies that any individual layer, either glass or plastic, of this laminated glazing is to be tested separately. Instead, the 14 tests applicable to Item 14 glazing set forth performance levels that must be achieved by the glazing as a laminate. One of the 14 tests designated for Item 14 is Penetration Resistance, Test No. 26. You are correct in noting that, effective September 23, 1991, Test No. 26 specifies the glass-plastic specimen is to be clamped into a test fixture before the specimen is tested. If an item of glass-plastic glazing passes each of the 14 tests applicable to Item 14 glazing, including Test No. 26, with clamping, and complies with Standard No. 205's labeling and certification requirements, the prime glazing material manufacturer of the material may designate that item of glass-plastic glazing as Item 14 glazing. You were also correct in your understanding that Standard No. 205 permits Item 14 glazing to be used for passenger car glazing in any position except the windshield of convertibles. I hope this information is helpful. Please feel free to contact Dorothy Nakama of my staff at this address or by telephone at (202) 366-2992 if you have any further questions or need additional information. Sincerely, Paul Jackson Rice Chief Counsel"; |
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ID: aiam0473OpenMr. Louis C. Lundstrom, Director, Automotive Safety Engineering, General Motors Technical Center, Warren, MI 48090; Mr. Louis C. Lundstrom Director Automotive Safety Engineering General Motors Technical Center Warren MI 48090; Dear Mr. Lundstrom: This is in response to your letter of October 19, 1971, in which yo asked whether the second and third options of Standard 208 require anthropomorphic test devices to be placed for the frontal crash tests only in the front designated seating positions, and not in the rear positions.; The answer is yes. The second and third options pose no requirement for testing that require dummies in the rear positions, hence dummies should be placed only in front positions. In the period from January 1, 1972 to August 15, 1973, they should in fact be placed only in the front outboard positions.; You also suggested that 'if Option 1 is used, a test device must be a each designated seating position.' This statement is true, in a strict sense. But the general requirements for the periods before August 15, 1975 (S4.1.1 and S4.1.2) explicitly allow the 'mixing' of options, so that if belts are provided for the rear seating positions they may be considered as fulfilling option two or three, without dummies positioned there for the crash tests. In other words, dummies must be positioned in the rear seating positions only if and when the manufacturer elects to fulfill option one for the rear positions.; Sincerely, Robert L. Carter, Acting Associate Administrator, Moto Vehicle Programs; |
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ID: aiam0166OpenMr. Francois Louis, Manager, Technical Standards Department, National Service and Parts Division, Renault, Incorporated, 100 Sylvan Avenue, Englewood Cliffs, NJ 07632; Mr. Francois Louis Manager Technical Standards Department National Service and Parts Division Renault Incorporated 100 Sylvan Avenue Englewood Cliffs NJ 07632; Dear Mr. Louis: Thank you for your letter of June 18, 1969, to the U.S. Department o Transportation, concerning your request for clarification of the visibility requirements of back up (sic) lamps as specified in Federal Motor Vehicle Safety Standard No. 108.; The visibility requirements for backup lamps on station wagons o similar type motor vehicles will be predicated on the normal driving, or closed tailgate, position. These lamps may therefore be mounted on the tailgate.; Sincerely, Charles A. Baker, Office of Standards on Accident Avoidance Motor Vehicle Safety Performance Service; |
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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.