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: aiam1565OpenMr. Ronald J. Hansing, Project Engineer, The Adams & Westlake Company, 1025 North Michigan Street, Elkhart, IN 46514; Mr. Ronald J. Hansing Project Engineer The Adams & Westlake Company 1025 North Michigan Street Elkhart IN 46514; Dear Mr. Hansing: This is in reply to your letter of July 3, 1974, regarding Moto Vehicle Safety Standard No. 217. You requested that we reconsider our opinion of June 11, 1974, that a bus emergency release mechanism which you describe must meet the requirements for emergency exit release in S5.3.2 of the standard after as well as before the retention test required by S5.1, when the glass breaks during the retention test.; Paragraph S5.3.2 requires that the release requirements be met bot before and after the retention test. We do not find sufficient justification to relax this requirement in the situation you described. First, it is not clear that it is as easy as you represent to eliminate by hand all of the glazing material left in the frame. More importantly, however, we still question whether most persons are sufficiently cognizant of the qualities of tempered glass to attempt to remove the remaining fragments in an emergency situation. Finally, glazing with completely different breakage characteristics may be used to replace the original tempered glass at some time during the life of the bus. For these reasons, our conclusion of June 11 remains the same.; Yours truly, Richard B. Dyson, Acting Chief Counsel |
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ID: aiam4767OpenMs. Betsy Dittemore Legislative Liaison Iowa Department of Public Safety Office of the Commissioner Wallace State Office Building Des Moines, Iowa 50319; Ms. Betsy Dittemore Legislative Liaison Iowa Department of Public Safety Office of the Commissioner Wallace State Office Building Des Moines Iowa 50319; "Dear Ms. Dittemore: Thank you for your letter regarding a bil introduced in the Iowa Senate that, among other features, would establish light transmittance limits for 'sunscreening devices' that may be applied to the windows of motor vehicles operated in Iowa. I apologize for the delay in this response. You requested our office's interpretation about whether provisions of this bill would violate or be preempted by Federal Motor Vehicle Safety Standard No. 205, Glazing Materials (49 CFR 571.205). As you are aware, this agency is authorized by section 103 of the National Traffic and Motor Vehicle Safety Act (15 U.S.C. 1392) to issue safety standards applicable to new motor vehicles and certain items of motor vehicle equipment. One of the standards that we have issued under this authority is Standard No. 205, which applies to all new vehicles and all new glazing materials for use in motor vehicles. Among the requirements set forth in Standard No. 205 are specifications for minimum levels of light transmittance (70 percent light transmittance in areas requisite for driving visibility, which includes all windows in passenger cars). Section 108(a)(1)(A) of the Safety Act (15 U.S.C. 1397(a)(1)(A)) specifies that no person may manufacture, import, or sell any vehicle in the United States unless it is in conformity with all applicable safety standards. Pursuant to section 108(b)(1) of the Safety Act (15 U.S.C. 1397(b)(1)), this prohibition no longer applies after the vehicle is sold to a consumer. However, both before and after the first sale, section 108(a)(2) of the Safety Act (15 U.S.C. 1397(a)(2)) provides that 'No manufacturer, distributor, dealer, or motor vehicle repair business shall knowingly render inoperative, in whole or part, any device or element of design installed on or in a notor vehicle or item of motor vehicle equipment in compliance with an applicable Federal motor vehicle safety standard . . . .' In the case of windows on a passenger car, this provision of Federal law means that no manufacturer, dealer, distributor, or repair business could install window tinting film that would result in a light transmittance of less than 70 percent for any window of the car, because such action would 'render inoperative' the vehicle's compliance with Standard No. 205. This same provision of Federal law prohibits a service station from permanently removing safety belts or permanently disconnecting brake lines on motor vehicles. Please note that the Safety Act does not apply to the actions of vehicle owners. Vehicle owners may alter their own vehicles and operate them on the highways as they please, even if the vehicle's windows no longer comply with the requirements of Standard No. 205. Hence, no provision of a Federal statute or this agency's regulations prevents individual vehicle owners themselves from tinting the windows on their vehicles. The individual States, however, have the authority to regulate the modifications that vehicle owners may make to their own vehicles and to establish requirements for vehicles operated or registered in that State. The Iowa Senate bill enclosed with your letter appears to be an attempted exercise of this inherent authority. You asked for comments on whether this bill, if adopted as law in Iowa, would be preempted by Standard No. 205. I assume you were referring to the provision in this Iowa bill that would prohibit the operation of motor vehicles required to be registered in the State of Iowa if the vehicle has a 'sunscreening device' on the front side windows with light transmittance of less than 35 percent or on the rear window and side windows behind the driver with light transmittance of less than 20 percent. Since the original glazing on the vehicle could have had light transmittance of as little as 70 percent, this provision would permit overall light transmittance levels of as low as 25 percent for the front side windows and 14 percent for the rear windows. This provision in the Iowa bill, and similar provisions in statutes adopted by other States, does not purport to legitimize conduct -- the rendering inoperative of glazing by firms installing window tinting -- that is illegal under Federal law. In other words, firms installing window tinting that results in light transmittance of less than 70 percent on any window of a passenger car would have violated the 'render inoperative' provision in Federal law, even if Iowa had in place a statute that would permit persons to operate and register vehicles whose windows had light transmittance that was far lower. Conversely, the Federal law setting requirements for the manufacture and sale of new vehicles and limiting the modifications commercial enterprises can make to those vehicles does not prohibit the State of Iowa from establishing lesser limits on owner modifications to their own vehicles and as the minimum requirements for vehicles to be operated and registered in the State of Iowa. Thus, there does not appear to be any legal conflict between Federal law and this Iowa bill, and Iowa would be free to enforce the provisions of this bill if it is enacted into law. We would, however, urge the State of Iowa to carefully consider the adverse safety consequences that would result from enacting this bill into law. NHTSA has determined that a 70 percent light transmittance minimum for new vehicles is the appropriate level to assure motor vehicle safety. Your letter indicated that Iowa had also adopted this 70 percent light transmittance minimum as a State requirement for new vehicles. It is not clear why the State of Iowa would conclude that the safety need that justifies requiring not less than 70 percent light transmittance in new vehicles is satisfied by allowing light transmittance levels as low as 25 and 14 percent in vehicles to be operated in the State. I hope that this information is helpful. If you have any further questions or need additional information about this topic, please feel free to contact Dorothy Nakama of my staff at this address or by telephone at (202) 366-2992. Sincerely, Paul Jackson Rice Chief Counsel"; |
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ID: aiam0724OpenMr. B. Fechner: (sic), FMC Corporation, Recreational Vehicles Division, 333 Brokaw Road, Box 664, Santa Clara, CA 95052; Mr. B. Fechner: (sic) FMC Corporation Recreational Vehicles Division 333 Brokaw Road Box 664 Santa Clara CA 95052; Dear Mr. Fechner:#This is in reply to your letter of May 25 inquirin about compliance of your planned motorhome with Federal Motor Vehicle Safety Standards Nos. 101 and 104.#Standard No. 101 requires certain controls to be illuminated. We interpret this to mean sufficiently illuminated that the control identification, if verbal, can be read, or if pictorial, can be understood. Therefore, illumination from any course is satisfactory as long as the basic requirement of comprehension is met.#Standard No. 104 does not describe the type of windshield wiping system that must be used to meet its requirements. It is the manufacturer's responsibility to insure, whatever system is used and whatever configuration of windshield is employed, that the wiped and washed area requirements are met.#Yours truly, Richard B. Dyson, Assistant Chief Counsel; |
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ID: aiam2774OpenMr. Philip A. Hutchinson, Jr., Volkswagen of America, 475 L'Enfant Plaza, S.W., Suite 2450, Washington, DC 20024; Mr. Philip A. Hutchinson Jr. Volkswagen of America 475 L'Enfant Plaza S.W. Suite 2450 Washington DC 20024; Dear Mr. Hutchinson: This responds to your January 30, 1978, request for confirmation tha no requirement in S 581.5(c) of the Part 581 *Bumper Standard* limits damage to the supporting ribs inside a plastic bumper face bar component or to the bumper face bar reinforcement component of the bumper system that lies within and reinforces the bumper face bar itself. You also requested confirmation that bumper 'end cuffs' are part of a bumper face bar if they are impacted by the impact ridge of the pendulum test device.; As we understand your description of the bumper reinforcement, it i not a bumper face bar, an exterior surface of the vehicle, or one of the other regulated portions of the vehicle. Therefore, it would not be regulated by the standard.; Internal deformation or cracking of the bumper face bar component doe not violate the provisions of S 581.5(3) as long as the dent and set requirements of (c)(11) are otherwise met.; 'Bumper face bar' is defined in S4 as 'any component of the bumpe system that contacts the impact ridge of the pendulum test device.' Protective ends or cuffs on a steel bumper face bar are considered components of the bumper system and, if contacted by the impact ridge of the pendulum test device, qualify under the definition as a portion of the bumper face bar subject to the same damageability limits as the rest of the bumper face bar.; Sincerely, Joseph J. Levin, Jr., Chief Counsel |
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ID: aiam0749OpenMr. John Forbes, Research Associate, Consumer Research Center, College of Business Administration, University of Puerto Rico, Rio Piedras, Puerto Rico 00931; Mr. John Forbes Research Associate Consumer Research Center College of Business Administration University of Puerto Rico Rio Piedras Puerto Rico 00931; Dear Mr. Forbes: This is in reply to your letter of June 9, 1972, raising certai questions concerning the National Traffic and Motor Vehicle Safety Act, and the Defect Reports regulations (49 CFR Part 573).; You ask whether the amendments made by sections 4(a) and (c) of Publi Law 91-265 took effect on November 28, 1970 or later. Section 4(d) of that law specified, as you note, that these sections take effect 180 days after the enactment of the Act, unless the Secretary of Transportation determined that a later date was in the public interest. No such determination was made, and the sections took effect 180 days after the Act's enactment. However, our computation shows that 180 days after May 22 is November 18, not November 28.; You ask if Owners Lists (49 CFR 573.6), including vehicl identification numbers, can be obtained by NHTSA and transmitted to your organization. The NHTSA would not consider it appropriate to require manufacturers to submit owner's (sic) lists to it for purposes not involved in the enforcement of the National Traffic and Motor Vehicle Safety Act. We would not consider the study you wish to perform to be within this purpose.; You also ask if we can furnish you copies of Quarterly Reports (49 CF 573.5) at least as they relate to cars sold in Puerto Rico. Quarterly reports submitted by manufacturers, except for the production figures submitted pursuant to section 573.5(b), are considered to be public documents and are available for public inspection. Due to the large number of reports we receive, however, we can furnish copies only if the precise reports desired are specified. The reports do not disclose the geographical location of the vehicles involved.; With reference to your request for the latest version of the leaflet 'Motor Vehicle Safety Defect Recall Campaigns,' I have enclosed the volume which provides information for the complete year 1971, and a new volume dealing with January-March 1972.; Sincerely, Lawrence R. Schneider, Chief Counsel |
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ID: aiam1508OpenMr. George D. Green, Director of Sales, JacKnife Division, Breeze Corporations, Inc., 700 Liberty Avenue, Union, NJ 07083; Mr. George D. Green Director of Sales JacKnife Division Breeze Corporations Inc. 700 Liberty Avenue Union NJ 07083; Dear Mr. Green: This is in reply to your letter of May 8, 1974, asking whether person installing on a new vehicle a device called the Breeze Jacknife Control are required to certify the conformity of the vehicle to applicable motor vehicle safety standards. You indicate such a device would ordinarily be installed after the truck leaves the factory.; Persons who install components on or otherwise modify complete vehicles before their sale to a purchaser for a purpose other than resale may be vehicle alterers under NHTSA Certification regulations (49 CFR Parts 567, 568), and if so are required to certify that the vehicle as altered conforms to applicable standards by attaching to it a label containing specified information. A label must be attached when the alteration either involves components which are not readily attachable or whose installation renders invalid the vehicle's stated weight ratings. Modifications to a completed vehicle after its purchase for purposes other than resale, however, do not give rise to any certification or labeling requirements.; Copies of the Certification regulations and information on obtainin copies of all NHTSA requirements are enclosed.; Yours truly, Richard B. Dyson, Assistant Chief Counsel |
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ID: aiam3535OpenLawrence W. Gebhardt, Gebhardt & Smith, Suite 1544, The World Trade Center, Baltimore, MD 21202; Lawrence W. Gebhardt Gebhardt & Smith Suite 1544 The World Trade Center Baltimore MD 21202; Dear Mr. Gebhardt: This is in response to your letter of November 30, 1981, in which yo raised several questions concerning the application of the exemption for dealer-to-dealer transfers of new cars. We are sorry for the delay in responding. Specifically you wanted to know if a dealer transferring a new vehicle with fifty miles registered on the odometer to another dealer was required to issue an odometer disclosure statement. You also requested that the agency provide you with cases subsequent to *Lair v. Lewis Service Center*, 428 F. Supp. 778 (D.Neb. 1977) which address the enforceability of the exemptions to Title IV of the Motor Vehicle Information and Cost Savings Act ('Act') (15 U.S.C. 1981 *et seq.*); Purchasers of motor vehicles rely heavily on the odometer reading as a index of the condition and value of the vehicle. The purpose of the Federal odometer laws is to establish certain safeguards against odometer tampering and to provide purchasers of motor vehicles an accurate statement of the mileage traveled by a motor vehicle. Section 408 of the Act requires that each transferor of a motor vehicle furnish to the transferee a written statement certifying the accuracy of the mileage. 15 U.S.C. 1988. The Odometer Disclosure Requirements specifically detail the information that must be disclosed. 49 CFR 580.4. However, the agency has determined that the exemption of certain transactions and vehicles is consistent with the purposes and scope of the Act. 49 CFR 580.5.; 49 CFR 580.5(b) exempts all transfers of a new vehicle prior to th first transfer to a customer who actually plans to use the vehicle from the Odometer Disclosure Requirements. The exemption applies to the dealer-to-dealer transfer of new vehicles regardless of the odometer reading. However, the exemption does not preclude a dealer from requiring the transferring dealer to certify the accuracy of the mileage.; The exemption is consistent with the purpose and scope of the Federa odometer laws. It is customary for dealers to transfer new vehicles to other dealers who plan to immediately resell the vehicle to a customer. Generally, the frequency of odometer fraud in these transactions is minimal. Indeed, prior to the transfer of a vehicle to a consumer, the odometer reading should only reflect the mileage accumulated while the vehicle is being demonstrated to a potential buyer or driven a short distance, which might be occasioned by a typical dealer-to-dealer transfer. We are unable to establish by issuing an opinion letter what the limit of such mileage incidental to the sale of a new car should be. If a dealer doubts the accuracy of the odometer reading, he can readily inspect the car for evidence of odometer tampering. In the absence of such evidence, the first dealer to sell the vehicle to a non-resale purchaser should be free to certify the mileage as accurate. The agency therefore views the issuance of odometer disclosure statements in such dealer-to-dealer transactions as unnecessarily burdensome on dealers.; In addition to *Lair v. Lewis Service Center*, the agency has knowledg of one other case *Romeri Trucking, Inc. v. Boise Kenworth Sale*, No. 80-1252 (D. Iowa, February 11, 1981), that addresses the issue of the enforceability of 49 CFR 580.5(a)(1). To date the agency has not issued a formal opinion on either case.; Sincerely, Frank Berndt, Chief Counsel |
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ID: aiam1158OpenMr. James W. Livsey, The Southern Connecticut Gas Co., 880 Broad Street, Bridgeport, Connecticut 06609; Mr. James W. Livsey The Southern Connecticut Gas Co. 880 Broad Street Bridgeport Connecticut 06609; Dear Mr. Livsey: This is in reply to your letter to Mr. David Snyder of this agenc regarding information on tests performed on recapped tires, specifically, data comparing failure characteristics of retreaded tires with those of new tires.; The NHTSA does not presently have test data of the specific type yo request. We are attempting to obtain that data through research contracts with outside parties, and results of that research, when they are received, will be placed in the rulemaking docket regarding retreaded tires. Other test data for retreaded tires have been placed in this docket (Docket No. 1-8), which is open for public inspection at NHTSA headquarters, 400 7th Street, S.W., Washington, D.C.; Certain studies have been conducted on the failure rates of tires, an some comparative data have been complied. One volume with which we are familiar summarizes studies which provided information of this type. It is, Brenner and Harvey, Tire Use Survey, the Physical Condition, Use and Performance of Passenger Car Tires in the United States of America, NBS Technical Note 528, (National Bureau of Standards U.S. Department of Commerce). Copies are available from the Superintendent of Documents, U.S. Government Printing Office, Washington, D.C. 20402. It should be ordered by SD Catalog No. C13.46:528, prepaid, at 60 a copy.; Yours truly, Richard B. Dyson, Assistant Chief Counsel |
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ID: aiam3165OpenMr. E. M. Ryan, Ward Industries, Inc., P.O. Box 849, Highway 65 South, Conway, AR 72032; Mr. E. M. Ryan Ward Industries Inc. P.O. Box 849 Highway 65 South Conway AR 72032; Dear Mr. Ryan: This responds to your October 8, 1979, letter asking whether your ne bus design will comply with Standard No. 217, *Bus Window Retention and Release*. The window exit that you plan to install in the bus would slide open rather than push out and would be operated by a squeeze-type force application that is parallel to the horizontal centerline of the bus.; Standard No. 217 requires buses to be equipped with emergency exit that comply with a variety of requirements. In the case of window exits, the force application for opening them depends upon the location of the release mechanism. For example, the required force application in the high force access region, according to the standard (S5.3.2), is straight and perpendicular to the exit surface.; In applying the above requirement to your vehicle, it appears that you bus would not comply with the standard. From the pictures that you enclosed with your letter, it appears that your release mechanism falls in the high force access region. If so, the force application for opening the exit is in the incorrect direction as specified by the standard. Further, your bus would use window exits that slide open rather than push out. Although, sliding emergency exits are not prohibited by the standard, they must comply with all of the standard's requirements. Also, they must be capable of complying when the non-exit half of the window is either open or closed. The agency prefers the use of push-out emergency exits, because they are less likely to 'bind up' during a side impact than sliding emergency exits.; The standard was written in its present form to provide uniformity o emergency exits in buses. A uniform exit system can help prevent confusion during accidents and facilitate emergency exit of vehicles. The vehicle that you plan to build would be unlike other buses now in operation with respect to emergency exits. The NHTSA does not think that this would be desirable or in the interest of safety.; Sincerely, Frank Berndt, Chief Counsel |
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ID: aiam3470OpenDick Sorensen, Brekhus Buick-International, Box 1357, Rapid City, SC 57701; Dick Sorensen Brekhus Buick-International Box 1357 Rapid City SC 57701; Dear Mr. Sorensen: This is in response to your letter of September 10, 1981, in which yo requested information on the Federal odometer disclosure requirements and specifically on their applicability to trucks with a gross vehicle weight rating (GVWR) of over 16,000 pounds. I have enclosed a copy of Title IV of the Motor Vehicle Information and Cost Savings Act (15 U.S.C. 1981 et seq.) which sets forth the Federal law pertaining to odometers. Section 404 of the Act prohibits any person from altering the odometer of any motor vehicle including trucks of more than 16,000 pounds GVWR.; I have also enclosed a copy of the odometer disclosure requirements (4 CFR Part 580). I have highlighted in red the exemption that applies to large trucks. The agency found that purchasers of these trucks do not rely on the odometer as an indicator of their mileage and, therefore, exempted them from the disclosure requirements. Before you decide whether or not to issue odometer disclosure statements for these trucks, I would like to alert you to the fact that at least one court has held that the agency exceeded its authority in fashioning this exemption and has declared it void. *Lair v. Lewis Service Center*, 428 F.Supp. 778 (D.Neb. 1977). The holding is not binding on any other court and the agency believes the exemption is valid. Nevertheless, you should be aware that should the issue arise again, another court could take a similar view.; I hope that this information is useful to you. If you have any furthe questions, please do not hesitate to write.; Sincerely, John Womack, 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.