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: aiam3028OpenMr. Don M. Carnahan, Superintendent of Public Instruction, Old Capitol Building, Olympia, WA 98504; Mr. Don M. Carnahan Superintendent of Public Instruction Old Capitol Building Olympia WA 98504; Dear Mr. Carnahan: This responds to your May 10, 1979, letter asking about modification of buses to reduce seating capacity so that they no longer must comply with school bus safety standards.; First, let me clarify several points. In applying motor vehicle safet standards, we define a 'school bus' as a bus that transports children to or from school or related events. Our regulations further define 'bus' as a vehicle designed for carrying more than 10 persons. The phrase 'more than 10 persons' includes the driver. Accordingly, any vehicle that transports 11 people is a bus.; Your first problem appears to involve how to determine whether vehicle is designed to carry more than 10 persons. You indicate, for example, that some manufacturers have attached labels to their vehicles stating that they are designed to transport 15 passengers. However, some of the vehicles only have 8 or 9 seats. The National Highway Traffic Safety Administration measures vehicle capacity by the number of designated seating positions. Therefore, a vehicle that has 8 designated seating positions is not a bus. Such a vehicle would be a multipurpose passenger vehicle. If you are unsure of the vehicle type, refer to the vehicle certification label located on the door pillar post or on the inside of the door. That label lists the vehicle type as established by its manufacturer.; Any vehicle that is sent from its manufacturer and certified i compliance with multipurpose passenger vehicle (MPV) standards may be used to transport school children. These vehicles, since they are not buses, need not comply with the school bus safety standards. On the other hand, any vehicle that is certified as a bus, but not a school bus, should not be used to transport school children.; You ask whether a bus can be modified by removing seats so that i would no longer be of a passenger capacity that would require it to comply with the school bus safety standards. In theory such a modification is permissible. If a dealer makes such a modification, it must attach an alterer's label in accordance with Part 567.7, *Certification*, of our regulations. Since the dealer would be changing the vehicle type (from bus to MPV), it must make sure that the vehicle complies with all of the standards applicable to the new vehicle type. This might be difficult since some different standards apply to multipurpose passenger vehicles than apply to buses. However, it is conceivable that the initial vehicle manufacturer might be able to assure the dealer that the vehicle was built in compliance with all necessary standards. In such a case, the dealer could attach a label, and the vehicle would be properly certified.; If a school modifies its own vehicles, it need not attach a label Also, it need not assure that the vehicles comply with any standards. In the event of an accident, however, a school could incur substantial liability if it were operating a vehicle that was not in compliance with the appropriate safety standards.; In your final question you ask what agency enforces the standard against dealers and manufacturers. The National Highway Traffic Safety Administration enforces all of the motor vehicle safety standards.; Sincerely, Frank Berndt, Chief Counsel |
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ID: aiam1015OpenMr. Gerhard Kutschera, Semperit of America, Inc., 156 Ludlow Avenue, Northvale, New Jersey 07647; Mr. Gerhard Kutschera Semperit of America Inc. 156 Ludlow Avenue Northvale New Jersey 07647; Dear Mr. Kutschera: This is in reply to your letter of January 25, 1973, inquiring whethe size designations '225/70SR14 replaces G70SR14', and '215/70SR15 replaces F70SR15' etc., may be used under Federal Motor Vehicle Safety Standard No. 109.; Paragraph S4.3(a) of Standard No. 109 provides for the labeling of 'on size designation, except that equivalent inch and metric size designation may be used.' The NHTSA has taken the position that this requirement does not prohibit the labeling of replacement sizes when the replaced size is in fact being superseded by the replacement size.; Because your proposed label contains both a metric and an inch siz designation, however, it is not clear whether these size designations are intended as 'equivalent' or 'replacement' sizes. If you intend the former size to supersede the later, your use of 'replaces' between the two size designation is consistent with Standard No. 109, If your intention is to label equivalent size designation, however, the use of 'replaces' is inappropriate. One way in which equivalency may be appropriately shown is to place the inch size designation if a parenthesis () immediately following the metric size designation.; One last point is that the size designation listed in the Appendix o Standard No. 109 for 70 Series radial ply tires differ from those specified in your letter. Table I-G, which lists this tire type, specifies size designations in which the second letter is and 'R'. Thus, the size designations which you submit should have read GR70SR14 and FR70SR15. Other size designations of this tire type should be identified accordingly.; Yours truly, Richard B. Dyson, Assistant Chief Counsel |
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ID: aiam4217OpenJohn Fleder, Esq., Director, Office of Consumer Litigation, Department of Justice, P.O. Box 386, Washington, D.C. 20044; John Fleder Esq. Director Office of Consumer Litigation Department of Justice P.O. Box 386 Washington D.C. 20044; Dear Mr. Fleder: This is in response to the request from Don O. Burley of your offic for the National Highway Traffic Safety Administration's interpretation of the Federal Odometer Disclosure Regulation, 49 C.F.R. Part 580. Specifically, Mr. Burley questioned the identity of the parties required to retain odometer disclosure statements under 49 C.F.R. S 580.7.; In 1977, the Agency decided that a regulation requiring the dealer o distributor to retain the statements issued to him (transferee odometer statements) and the statements he issued (transferor odometer statements) would enhance the value of odometer disclosure statements as investigatory tools. Therefore, the Agency proposed the following regulation:; >>>Each dealer or distributor of a motor vehicle shall retain for fou years each odometer mileage statement which he receives. He shall also retain for four years a photostat, carbon, or other facsimile copy of each odometer mileage statement which he issues. . . .<<<; 42 Fed. Reg. 58547 (1977). General Motors responded to this notice by questioning the regulation' application to manufacturers. Section 402 of the Motor Vehicle Information and Cost Savings Act (the 'Act'), 15 U.S.C. S 1982, defines 'dealer' as 'any person who has sold 5 or more motor vehicles in the past 12 months to purchasers who in good faith purchase such vehicles for purposes other than resale.' In addition, the Act defines 'distributor' as 'any person who has sold 5 or more vehicles in the past 12 months for resale.' Therefore, under the regulation as proposed, a manufacturer was defined as a distributor and would have been required to retain odometer disclosure statements. However, the Agency noted that since 49 C.F.R. S 580.5 specifically exempts manufacturers who sell vehicles to dealers from the requirements of executing odometer disclosure statements, manufacturers would not be required to retain any statements. 43 Fed. Reg. 18922 (1977) To clarify these apparently contradictory provisions, the modifying phrase 'who is required by this Part to execute an odometer disclosure statement' was added to the retention requirements following the words 'motor vehicle.' It was not the intent of the Agency by the insertion of this phrase to relieve dealers and distributors from the requirement of retaining odometer statements which they receive from a transferee.; Insurance companies and financial institutions also questioned th scope of the proposed regulation. The Agency noted that insurance companies and financial institutions do not fall within any of the exemptions set forth in 49 C.F.R. S 580.5 and that they must execute and retain odometer disclosure statements unless the transfers involve vehicles that are so badly damaged that they cannot be returned to the road. 43 Fed. Reg. 10922 (1978). The intent of this interpretation was to notify such institutions that they must retain all transferor odometer statements which they execute as well as all transferee odometer statements. I have enclosed a copy of the notice of proposed rulemaking (NPRM), the applicable comments and the final rule. Since the NPRM, we have not received any other correspondence concerning the retention requirement.; It is the Agency's interpretation that unless a dealer or distributo is exempt under 49 C.F.R. S580.5 from executing an odometer statement or unless he is transferring vehicles that are so badly damaged that they cannot be returned to the road, the dealer or distributor must retain both the statements issued to him and the statements he issued. The retention requirement affords the Government and aggrieved parties with the necessary documentation to prove a violation of the Act and to pinpoint exactly where the violation occurred.; If I can be of further assistance, do not hesitate to contact me. Sincerely, Erika Z. Jones, Chief Counsel |
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ID: aiam3478OpenMr. Jack DiMaio, Semperit of America, Inc., 156 Ludlow Avenue, Northvale, NJ 07647; Mr. Jack DiMaio Semperit of America Inc. 156 Ludlow Avenue Northvale NJ 07647; Dear Mr. DiMaio: This is in response to your telephone inquiry of October 13, 1981 asking whether tire tread labels required under the Uniform Tire Quality Grading (UTQG) Standards must continue to be affixed to tires once applicable UTQG grades are added to sidewall molds for the tires. The UTQG regulation contemplates that tire grading information will be made available to consumers simultaneously through a variety of means, including tread labels (49 CFR S 575.104(d)(1)(i)(B)), sidewall molding (49 CFR S 575.104(d)(1)(i)(A)), and leaflets available at the point of sale (49 CFR S 575.104(d)(1)(ii)). While the regulation was recently amended to permit tire grades to be molded on the tire sidewall at any time up to six months after introduction of a new tire line (46 FR 41514, August 17, 1981), this change in no way affected the obligation imposed by S 575.104(d)(1)(i)(B) that UTQG tread labels be affixed to all replacement tires to which the regulation applies. Thus, once the sidewall molding requirement takes effect for a line of tires, the regulation requires that UTQG information be displayed on the tires both by means of sidewall molding and by labels attached to the tread surface.; Sincerely, Frank Berndt, Chief Counsel |
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ID: aiam1445OpenMr. Bruce J. Motyka, 2030 Laura Lane, Des Plaines, IL 60018; Mr. Bruce J. Motyka 2030 Laura Lane Des Plaines IL 60018; Dear Mr. Motyka: This is in reply to your letter of March 11, 1974, asking fo suggestions regarding problems you have experienced with your pickup truck-camper unit.; It appears from your letter that no violations of Federal requirement have occurred. Motor Vehicle Safety Standard No. 126 and its companion Consumer Information requirement (49 CFR S 575.103) about which we wrote to you through Senator Percy's office did not become effective until January 1, 1973, well after the time you bought your vehicle. Moreover, it is not correct to characterize the dealer who sold you the unit as a 'final-stage manufacturer.' Under NHTSA requirements a pickup truck is a completed vehicle, and a person who installs a slide-in camper into the cargo area of a truck does not become a manufacturer. While this is not the case with chassis-mount campers, it is with respect to slide-in campers.; I suggest that if you wish to proceed further you consult an attorney who would be able to best assess your chances of success in civil litigation. The dealer's employee who told you that the 'GVW plate meant nothing' was mistaken. The weight ratings provided on the plate represent the manufacturer's representation of the maximum safe weight of a fully loaded vehicle.; You might wish to examine the labels attached, pursuant to Standard No 126 and 49 CFR S 575.103, to later models of both the pickup truck and camper you purchased. It is possible that those models and the ones you purchased are not substantially different. If that is the case the information on the labels can provide an indication of the extent that the weight ratings were exceeded by installation of the camper unit in question.; While I regret we cannot be of further assistance I wish you success i your efforts to solve this problem.; Yours truly, Richard B. Dyson, Assistant Chief Counsel |
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ID: aiam3182OpenMr. Steven J. Kalies, Union Springs Central School District, Union Springs, NY 13160; Mr. Steven J. Kalies Union Springs Central School District Union Springs NY 13160; Dear Mr. Kalies: During our telephone conversation, I envisioned the device yo described being covered by our Federal Motor Vehicle Safety Standard (FMVSS) 209, Seat Belt Assemblies. By the description on the price sheet you enclosed in your letter of 1/8/80, I am now not too sure. This device may not be covered under our FMVSS 213, Child Restraint(sic); After a conversation with the NHTSA's Office of Chief Counsel, I a taking the liberty of forwarding your letter to them for their review and response. It would be helpful if a brochure or picture of this device could be sent to our Washington Office. If available, mail it to: NHTSA, Office of Chief Counsel (NOA-30), 400 7th Street, S.W., Washington, D.C. 20590, ATTN: Mr. Stephen L. Oesch.; Thank you for bringing this matter to our attention. Sincerely, Irving Rodness, Motor Vehicle Program Specialist |
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ID: aiam4647OpenI; I; Mr. Dan Trexler Specifications Engineer Thomas Built Buses, Inc. P.O Box 2450 High Point, NC 27261 Dear Mr. Trexler: This is in reply to your letter of May 8, l989, to the former Chief Counsel of this agency, Erika Jones. You have received requests 'to install a master electrical disconnect switch on many buses.' When the switch is turned to the 'off' position 'it renders inoperative the warning signals (to the driver) required by FMVSS l05, 121 and 217. It also inactivates the hazard warning flasher required by FMVSS 108.' You ask whether installation of the switch would constitute a noncompliance, or a 'safety related hazard.' if it is accessible to the seated driver, or if remotely located in the battery or engine compartment, without ready access to the driver. Although you have not explained the purpose of such a device, we understand that a battery disconnect switch of this nature is deemed desirable by many bus owners to prevent drains on the battery when the bus is at rest. When the switch is activated, the bus cannot be started and driven because electric power is not available. Under this circumstance we do not believe that the switch either creates a noncompliance with any of the standards listed, nor constitutes a safety related defect, regardless of its location. When the bus is in operation the warning systems of the standards are not affected. The possibility of inadvertent activation when the bus is in use does not constitute a defect in performance, construction, components, or materials such as to create a safety related defect. To forestall any possibility of inadvertent activation, however, you may find it preferable to locate the switch away from the driver. We understand that a purpose of this switch is to reduce the likelihood of fire after accidents in which there has been fuel spillage. In this circumstance, it is likely that the bus would be positioned either in the roadway or adjacent to it. Safety would be enhanced if the hazard warning signal power source were separate from the batteries inactivated by the disconnect switch, so that these warning lamps could continue to operate. Sincerely, Stephen P. Wood Acting Chief Counsel /; |
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ID: aiam4352OpenDr. Ernst, Hella KG Hueck & Co, Postfach 28 40, 4780 Lippstadt, GERMANY; Dr. Ernst Hella KG Hueck & Co Postfach 28 40 4780 Lippstadt GERMANY; Dear Dr Ernst: This is in reply to your letter of February 5, 1987, to Richard Va Iderstine of this agency's Office of Vehicle Safety Standards. You have asked for an interpretation of Motor Vehicle Safety Standard No. 108 with respect to a new headlamp manufactured by Hella that BMW has installed on a new car which it introduced in the United States around April 1, 1987.; The headlamp is of the replaceable bulb type, and as you describe i consist of two additional parts: 'the housing, to which the cover lens is bonded by means of a two-component adhesive', and 'the optical module, consisting of the reflector and the convex lens, joined by the lens carrier....' In your words, 'The two parts are held together by three screws', and you believe that 'the two parts, firmly screwed together, are as effectively joined as would be the case if bonded'.; Paragraph S3 of Standard No. 108 defines a 'replaceable bulb headlamp in pertinent part as 'a headlamp comprising a bonded lens and reflector assembly....' In the Hella design, the lens and reflector assembly are not bonded, and thus the headlamp is not a 'replaceable bulb headlamp' that is permissible for use on motor vehicle sold and used in the United States. The intent of the definition is to ensure that the headlamp lens and reflector are an integral replaceable unit, since that is the only means to assure a mechanically aimable replaceable bulb headlamp which is capable of using any replacement standardized replaceable light source and meets the necessary photometric performance. The foundation of mechanical amiability is that the beam and aiming pad are manufactured to have a specific relationship. If this relationship is altered by replacement of the lens only, or of the reflector only, there is a high likelihood that the lamp may not meet minimum performance requirements when aimed mechanically.; Sincerely, Erika Z. Jones, Chief Counsel |
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ID: aiam3497OpenMr. Kenneth G. Moyer, 6400 Goldbranch Road, Columbia, SC 29206; Mr. Kenneth G. Moyer 6400 Goldbranch Road Columbia SC 29206; Dear Mr. Moyer: This is in reply to your letter of September 22, 1981, about you 'alert device which automatically turns on the stop lamps of the vehicle when the accelerator is released.' You wish our permission to install the device for experimentation and testing on other vehicles, as well as an interpretation of Federal Motor Vehicle Safety Standard No. 108 whether your device is allowable.; As you know, the agency has devoted considerable effort to improve rea braking signals, culminating in its proposal that passenger cars be equipped with a single high- mounted stop lamp on the centerline of the vehicle. The concept of a pre-brake application signal is a familiar one to us, but the agency has conducted no formal research with respect to it, and in view of its stop-lamp proposal, is unlikely to do so. The technical issues that we consider relevant to your concept are (1) whether most rear-end accidents are preceded by a 'panic' stop by the struck vehicle, (2) whether panic stops involve unique driver behavior that can be reliably discriminated from non-panic stop behavior and used to trigger a pre-braking signal, and (3) whether the resulting signal will automatically result in a decrease in the reaction time of following drivers that is equal to the early warning time it provides. We know of no scientifically acceptable data that support these critical assumptions. We are especially concerned that a high rate of 'false alarms' may lead to a decrease in the overall warning value of the stop lamp signal itself, i.e., the 'cry wolf' phenomenon. This could lead to a significant reduction in the effectiveness of any proposed system.; Paragraph 2.1 of SAE Standard J586d, *Stop Lamps*, September 1977 incorporated by reference in Standard No. 108, defines a stop lamp as one whose operation indicates 'the intention of the operator of a vehicle to stop or diminish speed by braking.'; Your device would activate the stop lamp under a condition indicatin an intent other than the above, which could impair the effectiveness of the stop lamps. We view any use of required lighting equipment for a purpose other than as defined, as an 'impairment' within the prohibition of paragraph S4.1.3 of Standard No. 108 if the device is installed as original equipment. If the device is sold in the aftermarket, our laws preclude modifications that 'render ineffective in whole or in part' required lighting equipment, if the modifications are performed by a person other than the vehicle owner. We would consider your system prohibited by this provision as well.; Noting your comment that the device may be used for testing on schoo buses, this means that there is no prohibition under the laws that we administer which would forbid a school district from installing your device on its fleet. Such a modification would be subject to laws of the jurisdiction in which the school bus is registered and operates.; Sincerely, Frank Berndt, Chief Counsel |
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ID: aiam1150OpenMr. Thomas Pieratt, Truck Equipment & Body Distributors Assoc., 602 Main Street, Cincinnati, OH 45202; Mr. Thomas Pieratt Truck Equipment & Body Distributors Assoc. 602 Main Street Cincinnati OH 45202; Dear Mr. Pieratt: This is in reply to your letter of May 11, 1973, in which you ask abou the certification responsibilities for consecutive manufacturers of certain multi-stage vehicles that are intended for use by utilities. The facts as you present them are that a chassis-cab is purchased by a customer and delivered to a utility distributor, who installs a sub-base and a digger-derrick. The truck is then sent to a body-builder who installs a body consisting essentially of storage compartments, which are used to carry personal tools. The compartments are installed to the floor installed by the utility distributor. The unit is then returned to the utility distributor, who installs clearance and other lamps, reflectors, and other accessories, and hooks up hydraulic lines. Smaller vehicles are described as being manufactured in essentially the same manner.; It appears to us that the manufacturing operations you have describe fit quite readily into the manufacturing categories established by Parts 567 and 568. The utility equipment distributor is an intermediate manufacturer, he performs manufacturing operations, but does not complete the vehicle, as further manufacturing operations, the installation of the body, are clearly contemplated for the vehicle to perform its intended function. The body-builder is the final-stage manufacturer. When he completes his work the vehicle is ready to perform its intended function, except for the addition of the lighting equipment and the other operations performed by the utility equipment distributor. These latter operations appear to involve 'readily- attachable components' and if so the party performing them would not be a final-stage manufacturer.; The certification requirements do not operate differently because, i the case you describe, the utility equipment distributor performs operations on the vehicle at two separate times (installing the derrick, and later the lighting). His responsibilities each time are governed by the operation he then performs. However, inasmuch as the utility distributor appears to perform much of the heavy manufacturing, and because he is also the last person to modify the vehicle, he may wish to assume the responsibility for certification under section 568.7(b), in order that he may affix his name as the manufacturer to the certification label.; Yours truly, Richard B. Dyson, Assistant 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.