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: aiam0783OpenMr. Julian Asch, Superex of Ramsey, Ltd., P.O. Box 10, Ramsey, New Jersey 07446; Mr. Julian Asch Superex of Ramsey Ltd. P.O. Box 10 Ramsey New Jersey 07446; Dear Mr. Asch: I am writing in response to your letter of May 26 regarding Standar 125, Warning Devices. You state that you are the National distributer of imported warning triangles, and ask whether you are permitted under paragraph S5.1.4(a) to place your name rather than that of the manufacturer on the device. The answer to your question is no: the standard requires that the name of the actual manufacturer, and not that of the distributer, be permanently and legibly marked on the warning device.; Sincerely, Richard B. Dyson, Assistant Chief Counsel |
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ID: aiam1891OpenHonorable Birch Bayh, United States Senate, Washington, DC 20510; Honorable Birch Bayh United States Senate Washington DC 20510; Dear Senator Bayh: This is in response to your letter requesting information concernin correspondence from one of your constituents, Mr. Albert E. Huber, commenting on a proposed amendment to the Federal bumper standard.; On January 2, 1975, the National Highway Traffic Safety Administratio (NHTSA) issued a Federal Register notice (copy enclosed) proposing to reduce the current 5 mph bumper impact requirements to 2.5 mph until the 1979 model year. The impact requirements would have been increased to 4 mph for 1979 and later model year cars.; The proposal was based primarily on the results of two agency-sponsore studies which indicated that the cost and weight of many current production bumpers, in light of inflation and fuel shortages, made the bumpers no longer cost beneficial. Information presented at public hearings on the bumper notice and comments submitted to the docket in response to the proposal have brought to light additional data. The NHTSA has carefully examined all of this evidence and reviewed its studies in light of the new information. As a result, the agency has concluded that the 5 mph protection level should not be reduced. This decision is contained in a Federal Register notice that was published March 12, 1975, which is enclosed (Docket No. 74-11, Notice 7, Docket No. 73-19, Notice 6).; We appreciate your interest and that of Mr. Huber in this importan area of motor vehicle performance.; Sincerely, James C. Schultz, Chief Counsel |
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ID: aiam2244OpenThomas M. Tucker, Assistant Manager, Titan Trailer Corporation, 1202 East Kentucky, P.O. Box 1517, Woodland, CA 95695; Thomas M. Tucker Assistant Manager Titan Trailer Corporation 1202 East Kentucky P.O. Box 1517 Woodland CA 95695; Dear Mr. Tucker: This responds to Titan Trailer Corporation's March 2, 1976, questio whether certain bulk grain and feed meal trailers manufactured by Titan qualify as bulk agricultural commodity trailers that are permitted until June 30, 1976, to meet emergency and parking brake requirements other than those specified in S5.6 and S5.8 of Standard No. 121, *Air Brake Systems*.; Sections S5.6 and S5.8 provide that a trailer manufactured before Jun 30, 1976, that is designed to transport bulk agricultural commodities in off-road harvesting sites and to a processing plant or storage location, as evidenced by skeletal construction that accomodates (sic) harvest containers, a maximum length of 28 feet, and an arrangement of air control lines and reservoirs that minimizes damage in field operations, is entitled to a specified option.; From the descriptive material enclosed, it appears that the Tita models 92 and 24 are designed for field use and conform to the criteria of skeletal construction that accomodates (sic) a harvest container, despite the fact that the container is permanently attached to the frame that surrounds it. It is not clear that the trailers are not more than 28 feet in length, or that the design positions air lines and reservoirs to minimize field-related damage. Assuming that the length, air lines, and reservoirs do meet these criteria, it appears that the trailers would qualify for the manufacturer option under S5.6 and S5.8.; Yours truly, Frank Berndt, Acting Chief Counsel |
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ID: aiam0279OpenMr. Y. Kosaka, Staff Engineer, Toyota Motor Co., Ltd, Lyndhurst Office Park, 1099 Wall Street West, Lyndhurst, NJ 07071; Mr. Y. Kosaka Staff Engineer Toyota Motor Co. Ltd Lyndhurst Office Park 1099 Wall Street West Lyndhurst NJ 07071; Dear Mr. Kosaka: This is in response to your letter of July 23, 1971, in which you aske a question concerning the requirement in Standard No. 208 that the seat belt warning signals deactivate when the parking brake is applied.; Your question was whether the standard's requirement would be satisfie by a system in which the seat belt warning signals deactivate at the same point at which the parking brake warning light goes on, considering the fact that the warning light is generally set to go on at a point where the parking brake lever is partially extended but before the brake is actually engaged.; We would consider the standard's requirement to be satisfied by th system you describe. We agree that the presence of the parking brake warning light is a sufficient deterrent to driving the vehicle with the parking brake partially engaged.; Sincerely, Lawrence R. Schneider, Acting Chief Counsel |
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ID: aiam5581OpenMr. Lance Tunick Vehicle Services Consulting, Inc. Post Office Box 1015 Golden, CO 80402-1015; Mr. Lance Tunick Vehicle Services Consulting Inc. Post Office Box 1015 Golden CO 80402-1015; Dear Mr. Tunick: This responds to your request for the agency t clarify the requirements of 49 CFR 575.101, which until recently required manufacturers to disclose information about the stopping performance of passenger cars and motorcycles. In particular, you asked how the requirement would apply to vehicles certified to comply with Federal Motor Vehicle Safety Standard No. 135, Passenger Car Brake Systems. I am enclosing a copy of a June 26, 1995, final rule in which the National Highway Traffic Safety Administration (NHTSA) rescinded section 575.101 (60 FR 32918). As a result of this decision, a vehicle manufacturer is no longer required to furnish information about the stopping performance of passenger cars and motorcycles. I hope this information is helpful to you. Should you have any questions or need additional information, please feel free to contact Marvin Shaw of my staff at this address or at (202) 366-2992. Sincerely, John Womack Acting Chief Counsel Enclosure; |
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ID: aiam2614OpenHonorable Clarence D. Long, House of Representatives, Room 200, Post Office Building, Towson, Maryland 21204; Honorable Clarence D. Long House of Representatives Room 200 Post Office Building Towson Maryland 21204; Dear Mr. Long: Your letter of May 9, 1977, to the Federal Trade Commission, on behal of Mr. Edward L. Armstrong, Sr., Baltimore, Maryland, expressing his concern that new passenger car manufacturers will discontinue supplying spare tires, has been referred to this office of the National Highway Traffic Safety Administration, Department of Transportation, for additional consideration and reply.; We believe that Mr. Armstrong's concern deals with the recentl approved 'temporary use' spare tire that will be manufactured and used with some of the new 1978 model automobiles. the use of a temporary use spare tire is not a new concept. These tires have been used with compact sport cars, such as Firebird and Camaro, since 1967. The further development of these spare tires has been fostered by the desire if the U.S. automobile manufacturers to produce small, lightweight cars in furtherance of the national energy conservation program. I am sure that you have noticed the new 1977 models by some domestic automobile manufacturers are, in fact, smaller. Of course, the development of these smaller, lightweight, energy-efficient automobiles has resulted in a substantial reduction in usable car trunk space, and therefore, providing a second reason to develop a spare tire which takes less storage space than a conventional tire.; Since this spare tire is designed for use in the nation's highways, i must conform to the minimum performance requirements of Federal Motor Vehicle Safety Standard (FMVSS) No. 109, *New Pneumatic Tires - Passenger Cars*, for strength, endurance and high speed performance, For your information, we have enclosed a copy of this standard.; Sincerely, Robert L. Carter, Associate Administrator, Motor Vehicl Programs; |
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ID: aiam0629OpenMr. A. T. Wood, CaraVan, Custom Conversions, 7879 Raytheon Road, San Diego, CA 92111; Mr. A. T. Wood CaraVan Custom Conversions 7879 Raytheon Road San Diego CA 92111; Dear Mr. Wood: This is in reply to your letter of February 21, 1972, in which yo request information on how to comply with the Defect Reports regulations (49 CFR Part 573). You state that your company converts vans into campers and other specialized uses, that some of your work is minor in nature, such as installing paneling, floors, or windows, and vents, and ask how to determine when you have developed a 'model' for reporting purposes under the regulations.; The Defect Reports regulations apply to 'manufacturers.' As a genera rule, a person who converts an already complete vehicle will be considered a manufacturer of the converted vehicle if he modifies it in such a way that the vehicle's structure or function is affected, to a significant extent. For example, a person who takes a basic van- type truck and makes extensive interior modifications to provide eating, sleeping, and bathroom facilities--producing what might be called a motor home, although nomenclature is not determinative--would be considered a manufacturer by the NHTSA. By contrast, a person who *only* added a window or some paneling at a customer's request would not be so considered. We recognize that a precise and universal line between these two polar examples is difficult to draw. For purposes of compliance with Part 573, we will accept a reasonable judgment on your part as to where the line should be drawn in your case.; Since your work is done on a custom basis, you may consider the 'make and 'model' language of the regulation as inapplicable to your production.; Yours truly, Richard B. Dyson, Assistant Chief Counsel |
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ID: aiam3906OpenMs. Janet M. Goodrich, 870 W. Versailles Ct., Baton Rouge, LA 70819; Ms. Janet M. Goodrich 870 W. Versailles Ct. Baton Rouge LA 70819; Dear Ms. Goodrich: This responds to your letter asking about regulations for automobil ignition systems and steering wheel locking systems. You asked for information concerning requirements for vehicles with automatic transmissions for the removal of the ignition key while the vehicle is in drive or any gear other than park. You specifically asked whether a driver should be able to remove the key from the ignition while the car is in drive even if the engine is no longer running.; Requirements relating to steering wheel locking systems are set fort in Federal Motor Vehicle Safety Standard No. 114, *Theft Protection*. Section S4.2 of the standard requires (among other things) that vehicles have a key-locking system that, whenever the key is removed, will prevent either steering or forward self- mobility of the vehicle, or both. Section S4.3 of the standard requires engine shall not activate the deterrent that prevents steering or forward self-mobility of the vehicle. Thus, the driver of an automobile may turn off the engine while the car is in motion without activating the steering column lock or impeding forward self-mobility.; Neither Standard No. 114 nor any other standard specifically require that vehicles be designed so that drivers are unable to remove the key from the ignition while the vehicle is in drive. I would note that the agency has conducted rulemaking addressing the issue of inadvertent activation of the steering column lock in moving vehicles. While the National Highway Traffic Safety Administration issued a notice of proposed rulemaking on this subject in May 1978 and a final rule in December 1980, the agency deleted the relevant requirements in a final rule and response to petitions for reconsideration, published in June 1981. In that latter notice, the agency stated that it had determined that the problem of inadvertent activation is not significant enough to require vehicles to be equipped with key-locking systems that provide more protection against inadvertent activation.; Standard No. 102, *Transmission Braking Effect*, also includes requirement relevant to your question. Section S3.1.3 requires that the engine starter for automatic transmission vehicles be inoperative when the transmission shift level is in a forward or reverse drive position.; Copies of Standards Nos. 102 and 114 and the three Federal Registe notices discussed above are enclosed for your convenience.; Sincerely, Jeffrey R. Miller, Chief Counsel |
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ID: aiam4113OpenMr. Robert P. Horbatt, President, Semperit Tire Company, 156 Ludlow Avenue, Northvale, NJ 07647; Mr. Robert P. Horbatt President Semperit Tire Company 156 Ludlow Avenue Northvale NJ 07647; Dear Mr. Horbatt: This responds to your letter to Stephen Kratzke of my staff, in whic you stated your interpretation of the requirements of the Uniform Tire Quality Grading Standards (49 CFR S575.104, 'UTQGS'). You stated that your company is introducing a new all-season tire to the United States market, and that you would like to import the first six months' production without the UTQGS grades molded onto the sidewall of the tires, but with paper labels showing those grades. This course of action is expressly permitted by the UTQGS.; First, the UTQGS is applicable to all-season tires. Sectio 575.104(c)(1) specifies that the UTQGS does not apply to 'winter-type snow tires.' The National Highway Traffic Safety Administration has explained that winter-type snow tires refers only to tires with a deep tread rubber and tread design which are inadvisable for year-round use on passenger automobiles. Since all-season tires are not 'winter-type snow tires,' they are subject to the requirements of the UTQGS. *See* 44 FR 30139, at 30140, May 24, 1979.; The requirement that the grades assigned under the UTQGS be permanentl molded onto one sidewall of each passenger car tire is set forth in 49 CFR S575.104(d)(1)(i)(A). However, that section reads:'*Except for a tire of a new tire line, manufactured within the first six months of production of the tire line*, each tire shall be graded with the words, letters, symbols, and figures ... permanently molded into or onto the tire sidewall....' A tire line introduced for the first time into the United States is considered a new tire line for the purposes of this section. Therefore, our UTQGS regulation does *not* require you to mold the assigned grades onto a sidewall of those tires manufactured within the first six months of production. Such tires are subject to the requirement that a paper label, showing the UTQGS grades assigned to the tire, be affixed to its tread surface (49 CFR S575.104(d)(1)(i)(B)), and that the grades assigned to those tires appear in the information furnished to prospective purchasers of the tires (49 CFR S575.6(c)).; If you have any further questions or need more information on thi subject, please contact Mr. Kratzke at this address or by telephone at (202) 426-2992.; Sincerely, Erika Z. Jones, Chief Counsel |
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ID: aiam1311OpenMr. W. Pudinski, Commissioner, Department of California Highway Patrol, P.O. Box 898, Sacramento, CA 95804; Mr. W. Pudinski Commissioner Department of California Highway Patrol P.O. Box 898 Sacramento CA 95804; Dear Mr. Pudinski: This is in response to your letter of October 1, 1973, in which yo asked that we review an enclosed opinion by the California Attorney General on the question of preemption of California motor vehicle regulations by Federal standards. The opinion concluded that the California requirement that motorcycles be wired so that their headlamps are lit whenever their engines are running was not preempted. This conclusion was contrary to the position taken in an NHTSA letter of November 14, 1972, to Mr. Edward Kearney.; We adhere to the position stated in the November 14, 1972, letter tha the California requirement is preempted, and consider the legal opinion by the California Attorney General to be an erroneous view of the Federal law.; The opinion properly viewed the question as turning on the applicatio of the phrase in S. 103(d) of the National Traffic and Motor Vehicle Safety Act, 15 U.S.C. 1392(d), 'applicable to the same aspect of performance.' If the Federal standard (Standard No. 108, 49 CFR 571.108) covers a given aspect of performance, any State requirement must be identical to it. The California opinion relied on the language in the main opinion of one of the Super Lite cases, *Chrysler Corp. v. Tofany*, 419 F.2d 499 (1969), that preemption should be 'narrowly construed', and went on to find that since Standard 108 does not specifically address the matter of wiring the headlamps when the engine is running, that aspect of performance is not covered by the standard and the California law is valid.; More important, however, than the nebulous concept of whethe preemption is 'narrowly' construed (a concept with which Judge Friendly, concurring in *Chrysler*, did not agree) is the point made at the end of the main opinion, that the administering Federal agency was supporting the State's position regarding the scope of the Federal regulation. The Court quoted the U.S. Supreme Court in *Thorpe v. Housing Authority of Durham*, 393 U.S. 268, 276 (1969):; >>>[W]hen construing an administrative regulation, 'a court mus necessarily look to the administrative construction of the regulation if the meaning of the words used is in doubt. . . . [T]he ultimate criterion is the administrative interpretation, which becomes of controlling weight unless it is plainly erroneous or inconsistent with the regulation.'<<<; In this case the situation is the opposite of that in the Super Lit cases. The NHTSA's position is that the standard does cover the aspect of performance in question. As stated in the NHTSA letter of November 14, 1972, the standard 'establishes requirements for motorcycle headlighting, along with special wiring requirements for motorcycles and other vehicles.' It is the intent of the NHTSA that its requirements for headlamp performance, configuration, and wiring cover all aspects of performance directly involving headlamps, and thus preempt any non-identical State standards relating to headlamps.; The implication of the California opinion is that any mode of design o performance that is not expressly dealt with in the Federal standard is open to regulation by the States. Such a position is impractical, where the agency's intent is to have a comprehensive, uniform regulation in a given area. In order to preempt the field it would be necessary for a Federal agency to anticipate the imaginative regulatory impulses of future State agencies or legislatures and include in a standard such provisions as, 'It is not required that motorcycle headlamps be wired to operate when the engine is running.' Congress clearly intended the NHTSA to establish a single set of uniform standards to which manufacturers must comply, and that intent would tend to be defeated by the position taken in the California opinion. Federal regulation has a negative as well as a positive aspect: in determining that there should be certain requirements in an area, we also are deciding against imposing others. The only way to effectuate such a decision is to declare, as we have done here, that our regulation is intended to be exclusive, and to describe as necessary its outer limits.; The California opinion's factual comparison with the Super Lite case is also inapt. The Super Lite itself was a new type of lighting equipment, a supplementary lamp, for which Standard 108 contained no requirements. Headlamps, by contrast, are comprehensively regulated by the standard.; For these reasons, we conclude that the California requirement tha motorcycle headlamps be wired to operate when the engine is running is preempted by Standard 108, and void.; While we feel constrained by law to so conclude, I want you to kno that I have instructed my staff to consider the merit of amending the Federal lighting standard to include the California requirement in 108.; Sincerely, James B. Gregory, Administrator |
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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.