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: aiam5533OpenMr. Jeffrey D. Shetler Manager of Government Relations Kawasaki Motors Corp., U.S.A. P.O. Box 25252 Santa Ana, CA 92718-2016; Mr. Jeffrey D. Shetler Manager of Government Relations Kawasaki Motors Corp. U.S.A. P.O. Box 25252 Santa Ana CA 92718-2016; "Dear Mr. Shetler: This responds to your letter of February 2, 1995 asking whether Safety Standards Nos. 108 and 123 permit a motorcycle turn signal pilot indicator to be green. You have noted that, under Table III of Standard No. 108, SAE J588 NOV84 is the appropriate standard that the National Highway Traffic Safety Administration (NHTSA) has incorporated by reference for motorcycle turn signal lamps. You have further noted that the SAE standard specifies requirements for turn signal pilot indicators if the front turn signal lamps are not readily visible to the driver. Finally, paragraph 5.4.3.3 of SAE J588 specifies that the indicator, if located on the outside of the vehicle, should emit a yellow-colored light. On the other hand, Standard No. 123, which specifies requirements for turn signal lamp identification, does not specify a color for turn signal pilot indicators. You believe that SAE J588 was written with passenger cars in mind and that its color and area requirements are specified because the location of an outside indicator lamp is further away than a lamp located inside the vehicle on the instrument panel. You also believe that Standard No. 123 does not need to address distance from the driver's eye because the turn signal lamp will always be within a reasonable distance from the driver's eye. Thus, you have concluded that any pilot lamp color would be acceptable. We have reviewed specifications of both the SAE and Standard No. 123. SAE J588 NOV84 Turn Signal Lamps for Use on Motor Vehicles Less Than 2032 MM in Overall Width is incorporated by reference in Standard No. 108, and, under Table III, is the standard specified for motorcycle turn signal lamps. Because paragraph S5.1.1 of Standard No. 108 does not contain a section modifying the applicability of J588 to motorcycles, all the requirements of J588 apply to motorcycles, including turn signal pilot indicators and their color. All that Standard No. 123 does, through Table III, is to specify the shape of the turn signal indicator. It is silent as to the color of the indicator. We believe that you are correct in your conclusion that J588 was not written with motorcycles in mind, at least for two-wheeled motorcycles such as Kawasaki makes. Two colors are prescribed by SAE J588, the choice of which depends on the location of the indicator. Under paragraph 5.4.3.2, a green-colored light 'with a minimum area of 18 sq. mm.' must be used 'if the illuminated indicator is located inside the vehicle.' Under 5.4.3.3 a yellow-colored light with 'a minimum projected illuminated area of 60 sq. mm.' must be used 'if the illuminated indicators are located on the outside of the vehicle, for example on the front fenders.' Since two-wheeled motorcycles do not have enclosed cabins, all references to 'inside' and 'outside' the vehicle are inapposite. Since you brought this matter to our attention, we have conducted an informal survey of the color of turn signal indicators on motorcycles sold in the United States. We find that the predominant color is amber, though Harley-Davidson, accounting for 12% of the market, uses green. We view the use of either color as in accord with J588. Therefore, if Kawasaki wishes to change its indicator color from amber to green, it will not violate Standard No. 108 by doing so. As J588's color specifications are coupled with those for the minimum illuminated area of the display, and you have not raised the question of an appropriate size for a green turn signal indicator, we call your attention to paragraph S5.2.2 of Standard No. 123 which requires that the display for turn signal lamps and other equipment 'be visible to a seated operator under daylight conditions.' If you have any further questions, Taylor Vinson of this office will be glad to answer them for you (202-366-5263). Sincerely, John Womack Acting Chief Counsel"; |
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ID: aiam5564OpenMr. Musa K. Farmand Gonz lez & Farmand, P.A. 555-B Blanding Boulevard Orange Park, FL 32073; Mr. Musa K. Farmand Gonz lez & Farmand P.A. 555-B Blanding Boulevard Orange Park FL 32073; "Dear Mr. Farmand: This responds to your letter of April 27, 1995. You letter concerns a law suit in which you represent plaintiffs injured in an automobile accident. In this law suit, the counsel for the defendant has moved to amend his answer to assert that 49 CFR 571.208, paragraph S4.1.5.2(c)(2) requires each state to allow for mitigation of damages in any seat belt use law and that paragraph preempts the Florida mandatory seat belt law. According to your letter, the Florida law 'does not allow a mitigation of damages defense with respect to an alleged failure to wear a seat belt.' As explained below, the National Highway Traffic Safety Administration agrees with you that the Florida safety belt use law is neither expressly nor impliedly preempted by Federal law. Purpose of Paragraph S4.1.5.2(c)(2) Before discussing the issue of preemption, I want to discuss the background and purpose of Paragraph S4.1.5.2(c)(2). That paragraph was added to Standard No. 208, Occupant Crash Protection (49 CFR 571.208) as part of a final rule issued July 17, 1984 concerning automatic restraints (49 FR 28962). That final rule required all new cars to have automatic protection (air bags or automatic belts) starting in the 1990 model year. The final rule included a provision that the automatic restraint requirement would be rescinded if the Secretary of Transportation determined, not later than April 1, 1989, that a sufficient number of States had enacted belt use laws meeting certain minimum criteria to cover at least two-thirds of the U.S. population (paragraph S4.1.5). Under S4.1.5, the Secretary was not required to make any determination about any State safety belt laws. In fact, the Secretary never did so, in part because not enough States adopted mandatory seat belt use laws of any sort prior to April 1, 1989. Because no determination was made under S4.1.5, the automatic restraint requirements are now in effect for all passenger cars. The minimum criteria were set forth in S4.1.5.2 of Standard No. 208. One of the criteria was 'a provision specifying that the violation of the belt usage requirement may be used to mitigate damages...' (S4.1.5.2(c)(2)). However, S4.1.5 neither purported to require nor was intended to require States to enact safety belt use laws. In addition, S4.1.5 did not require that any State safety belt use laws had to incorporate the minimum criteria of S4.1.5.2. Paragraph S4.1.5 merely provided that the Secretary would rescind the automatic restraint requirement if he or she determined that a sufficient number of States enacted laws which met the criteria of S4.1.5.2 by April 1, 1989. Preemption The Florida safety belt use law is not and never has been either expressly or impliedly preempted by Federal law. Standard No. 208 was issued under 49 U.S.C. Chapter 301 which expressly preempts state laws only to the extent provided by section 30103. That section provides for the express preemption of State motor vehicle safety standards that are not identical to Federal standards. However, the Florida seat belt law is not a motor vehicle safety standard within the meaning of Chapter 301, since it does not regulate motor vehicle or motor vehicle equipment performance. Accordingly, the Florida law is not expressly preempted. The Florida law is not impliedly preempted because (1) Congress has not occupied the field of regulation of the behavior of motor vehicle occupants, and (2) the Florida seat belt law does not conflict with any Federal law or interfere with the objectives of Federal law. I hope this information has been helpful. If you have other questions or need some additional information, please contact Mary Versailles of my staff at this address or by phone at (202) 366-2992. Sincerely, John Womack Acting Chief Counsel"; |
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ID: aiam5540OpenMr. Musa K. Farmand Gonz lez & Farmand, P.A. 555-B Blanding Boulevard Orange Park, FL 32073; Mr. Musa K. Farmand Gonz lez & Farmand P.A. 555-B Blanding Boulevard Orange Park FL 32073; "Dear Mr. Farmand: This responds to your letter of April 27, 1995. You letter concerns a law suit in which you represent plaintiffs injured in an automobile accident. In this law suit, the counsel for the defendant has moved to amend his answer to assert that 49 CFR 571.208, paragraph S4.1.5.2(c)(2) requires each state to allow for mitigation of damages in any seat belt use law and that paragraph preempts the Florida mandatory seat belt law. According to your letter, the Florida law 'does not allow a mitigation of damages defense with respect to an alleged failure to wear a seat belt.' As explained below, the National Highway Traffic Safety Administration agrees with you that the Florida safety belt use law is neither expressly nor impliedly preempted by Federal law. Purpose of Paragraph S4.1.5.2(c)(2) Before discussing the issue of preemption, I want to discuss the background and purpose of Paragraph S4.1.5.2(c)(2). That paragraph was added to Standard No. 208, Occupant Crash Protection (49 CFR 571.208) as part of a final rule issued July 17, 1984 concerning automatic restraints (49 FR 28962). That final rule required all new cars to have automatic protection (air bags or automatic belts) starting in the 1990 model year. The final rule included a provision that the automatic restraint requirement would be rescinded if the Secretary of Transportation determined, not later than April 1, 1989, that a sufficient number of States had enacted belt use laws meeting certain minimum criteria to cover at least two-thirds of the U.S. population (paragraph S4.1.5). Under S4.1.5, the Secretary was not required to make any determination about any State safety belt laws. In fact, the Secretary never did so, in part because not enough States adopted mandatory seat belt use laws of any sort prior to April 1, 1989. Because no determination was made under S4.1.5, the automatic restraint requirements are now in effect for all passenger cars. The minimum criteria were set forth in S4.1.5.2 of Standard No. 208. One of the criteria was 'a provision specifying that the violation of the belt usage requirement may be used to mitigate damages...' (S4.1.5.2(c)(2)). However, S4.1.5 neither purported to require nor was intended to require States to enact safety belt use laws. In addition, S4.1.5 did not require that any State safety belt use laws had to incorporate the minimum criteria of S4.1.5.2. Paragraph S4.1.5 merely provided that the Secretary would rescind the automatic restraint requirement if he or she determined that a sufficient number of States enacted laws which met the criteria of S4.1.5.2 by April 1, 1989. Preemption The Florida safety belt use law is not and never has been either expressly or impliedly preempted by Federal law. Standard No. 208 was issued under 49 U.S.C. Chapter 301 which expressly preempts state laws only to the extent provided by section 30103. That section provides for the express preemption of State motor vehicle safety standards that are not identical to Federal standards. However, the Florida seat belt law is not a motor vehicle safety standard within the meaning of Chapter 301, since it does not regulate motor vehicle or motor vehicle equipment performance. Accordingly, the Florida law is not expressly preempted. The Florida law is not impliedly preempted because (1) Congress has not occupied the field of regulation of the behavior of motor vehicle occupants, and (2) the Florida seat belt law does not conflict with any Federal law or interfere with the objectives of Federal law. I hope this information has been helpful. If you have other questions or need some additional information, please contact Mary Versailles of my staff at this address or by phone at (202) 366-2992. Sincerely, John Womack Acting Chief Counsel"; |
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ID: aiam4756OpenMr. Brian Gill Senior Manager Certification Department American Honda Motor Co., Inc. 100 West Alondra Boulevard P. O. Box 50 Gardena, California 90247-0805; Mr. Brian Gill Senior Manager Certification Department American Honda Motor Co. Inc. 100 West Alondra Boulevard P. O. Box 50 Gardena California 90247-0805; "Dear Mr. Gill: This responds to your request that this agenc determine that the new antitheft device proposed to be installed on the MY 1991 Honda Acura NS-X car line, represents a de minimis change in the system that was the basis for the agency's previous granting of a theft exemption for the car line beginning in MY 1991, and that therefore the Acura NS-X vehicles containing the new device would be fully covered by that exemption. As you are aware, the Acura NS-X car line was granted an exemption, pursuant to 49 CFR Part 543, from antitheft marking because Honda showed that the antitheft device to be used in lieu of marking on the car line was likely to be as effective as parts marking. This exemption was issued on February 5, 1990, and appeared in the Federal Register on February 9, 1990 (55 FR 4746). The agency granted the exemption from theft marking because the agency found that based on substantial evidence, the agency believed that the antitheft device is 'likely to be as effective in reducing and deterring motor vehicle theft as compliance with the parts-marking requirements of the theft prevention standard (49 CFR Part 541).' In the granting of the exemption from theft marking, the agency stated that it believed that the device will provide the types of performance listed in 49 CFR Part 543.6(a)(3): Promoting activation, attracting attention to unauthorized entries, preventing defeat or circumventing of the device by unauthorized persons, preventing operation of the vehicle by unauthorized entrants, and ensuring the reliability and durability of the device. In your letter, it was stated that beginning from MY 1991, Honda plans improvements in the antitheft device that is standard equipment on the Acura NS-X in two ways: First, the new antitheft system would be armed by using the auto door lock system control to lock either door. Honda states that in the system that was the subject of the exemption from the theft prevention system, it was necessary to use the control on the driver's door in order to arm the system. According to the attachment provided in your letter, this change would make it possible to arm the the theft deterrent system by locking either door even if the other door is left unlocked. Second, the radio would now be included in the alarm system. Thus, the alarm system will be activated if the radio terminal or the coupler is disconnected, or if the radio's wiring is cut. After reviewing the proposed changes to the componentry and performance of the antitheft device on which the exemption was based, the agency concludes that the changes are de minimis. While the new device has enhanced componentry and provides some aspects of performance not provided by the original device, it also continues to provide the same aspects of performance provided by the original device and relies on essentially the same componentry to provide that performance. Therefore, it is not necessary for Honda to submit a petition to modify the exemption pursuant to 49 CFR Part 543.9(c)(2). If Honda does not implement the new antitheft device as described in your letter, or delays implementation until after MY 1991, we request that Honda notify the agency of such decisions. It is my understanding that, in a May 16, 1990, telephone conversation between Brian Tinkler of Honda and Dorothy Nakama of NHTSA's Office of Chief Counsel, Mr. Tinkler confirmed that Honda was not requesting confidential treatment of any information provided in your letter. Therefore, a copy of your letter, and this response, will be placed together in NHTSA's public docket. Sincerely, Barry Felrice Associate Administrator for Rulemaking /"; |
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ID: aiam3696OpenMr. Ken Alexander, Engineering Manager, Sylvania GTE Products Corporation, 1231 'A' Avenue North, Seymour, IN 47274; Mr. Ken Alexander Engineering Manager Sylvania GTE Products Corporation 1231 'A' Avenue North Seymour IN 47274; Dear Mr. Alexander: This is in reply to your letter of April 8, 1983, following conversation with Mr. Vinson of this office, with reference to Standard No. 108 *Lamps, Reflective Devices, and Associated Equipment*.; You are concerned with the 'design to conform' language as it relate to headlamps, and have asked for an interpretation that it 'does not mean that every lamp produced is required to have every photometric point in.'; I am not certain what you mean by 'every photometric point in' However, a manufacturer is expected to design his headlamps so that each will meet the minimum photometric output in candela set forth by SAE J579C for each test point. The agency does not pursue random occasional photometric failures at individual test points. But if a manufacturer's products show a pattern of failures to meet the minimum at any individual test point, the agency could consider this as an indication that the headlamp was, in fact, not 'designed to conform'.; I hope this answers your question. Sincerely, Frank Berndt, Chief Counsel |
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ID: aiam1860OpenHonorable Herman E. Talmadge, United States Senate, Washington, DC 20510; Honorable Herman E. Talmadge United States Senate Washington DC 20510; Dear Senator Talmadge: This responds to your recent communication requesting consideration o a constituent's concern about the National Highway Traffic Safety Administration's standard requiring antiskid devices on new school buses for all states, although some states do not often have icy roads.; The regulation to which your constituent Mr. Smith refers is Federa Motor Vehicle Safety Standard No. 121, *Air brake systems*. This standard which became effective for trailers on January 1, 1975, and trucks and buses on March 1, 1975, specifies minimum performance requirements for service brake systems, emergency brake systems, and parking brake systems utilized on air-braked vehicles. The standard does not specifically require antilock devices, although S5.3.1 of the standard does specify minimum stopping distance and stability requirements on dry and wet roads. Most vehicle manufacturers have decided to utilize antilock devices to meet these requirements. The purpose of these requirements is to enhance vehicle stability during brake application on roads in all conditions, dry and wet, as well as icy. A copy of Standard No. 121 with amendments is enclosed.; Please write again if I can be of further assistance. Sincerely, James C. Schultz, Chief Counsel |
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ID: aiam2404OpenMr. Brian Gill, Assistant Manager, Safety & Environmental Activities, American Honda Motor Co. Inc., P.O. Box 50, Gardena, CA, 90247; Mr. Brian Gill Assistant Manager Safety & Environmental Activities American Honda Motor Co. Inc. P.O. Box 50 Gardena CA 90247; Dear Mr. Gill: This is in reply to your letter of September 23, 1976, asking for a interpretation of the spacing requirements for motorcycle turn signal lamps specified in Table IV of Motor Vehicle Safety Standard No. 108.; Standard No. 108 requires that motorcycle turn signal lamps be locate so that their edges are at least 4 inches from the edge of the headlamps (on the front) and tail or stop lamps (on the rear). You have asked for confirmation 'that the minimum separation distance is measured between the edges of the illuminated lenses of the respective lamps on a line passing through each lamp . . . rather than being measured on a horizontal line between two planes touching the edges of the illuminated lenses'.; This will confirm your interpretation that the minimum separatio distance is to be measured at the point where the edges of the two lamps are closest to each other.; Yours truly, Frank Berndt, Acting Chief Counsel |
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ID: aiam2500OpenMr. David F. Berry, Director, Quality Control & Special Products, Birmingham Manufacturing Company, Inc., P.O. Drawer 289, Springville, AL 35146; Mr. David F. Berry Director Quality Control & Special Products Birmingham Manufacturing Company Inc. P.O. Drawer 289 Springville AL 35146; Dear Mr. Berry: This responds to Birmingham Manufacturing Company's June 15, 1976 request to know the certification responsibilities of a manufacturer of low-bed trailers (of the removable goose-neck design) that provides the purchaser with the bed, suspension, and axle portions of the trailer without the gooseneck or the tires and rims. I apologize for our delay in answering.; The portion of the trailer you describe constitutes an 'incomplet vehicle' as that term is described in Part 568 of our regulations (Part 568 -- Vehicles Manufactured in Two or More Stages):; >>>S 568.3 *Definitions*. 'Incomplete vehicle' means an assemblage consisting, as a minimum, o frame and chassis structure, power train, steering system, suspension system, and brake system, to the extent that those systems are to be part of the completed vehicle, that requires further manufacturing operations, other than the addition of readily attachable components, such as mirrors or tire and rim assemblies, or minor finishing operations such as painting, to become a completed vehicle.; << |
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ID: aiam1236OpenMr. J.W. Kennebeck, Manager,Safety and Development,Volkswagen of America, Inc.,Englewood Cliffs, New Jersey 07632; Mr. J.W. Kennebeck Manager Safety and Development Volkswagen of America Inc. Englewood Cliffs New Jersey 07632; Dear Mr. Kennebeck:#This is in reply to your letter of August 8, 1973 to Mr. Schneider asking for confirmation of your interpretation of two sections of Standard No. 105a.#You ask first whether S5.3.1 requires that the activation of an indicator lamp upon application of 50 pounds of force be instantaneous, or whether a minimal time lag is permissible. You indicated that in a 'panic stop' there is a time lag of approximately 100 milliseconds between application of 50 pounds of force and lamp activities in the VW system. Since, as you state, it is 'humanly impossible' to discern such a minimal time lag, we consider that the VW system complies with S5.3.1, and that the lamp is activated upon application of 50 pounds of force.#You are also correct in your interpretation if S5.2.1 that the 5-minute requirement applies only to vehicles that do not exceed the limit of traction on a 30 percent grade.#Sincerely,Lawrence R. Schneider,Chief Counsel; |
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ID: aiam0804OpenMr. Charles R. Matthews, Sr. Safety Engineer, Oshkosh Truck Corporation, P. O. Box 560, Oshkosh, Wisconsin 54091; Mr. Charles R. Matthews Sr. Safety Engineer Oshkosh Truck Corporation P. O. Box 560 Oshkosh Wisconsin 54091; Dear Mr. Matthews: This is in response to your letter of July 5, 1972, requesting a opinion as to how manufacturers may take into account a vehicle's speed capability in establishing GAWR.; The Certification regulations do not specify particular speed criteri for establishing weight ratings. As a minimum, however, we believe the speed chosen should reflect the maximum speed at which it is reasonable to expect the vehicle to be driven. In the case where a vehicle is subject to some low-speed uses, such as seasonal sue as a snow plow, we believe the figure on the certification label should be based on that use of the vehicle in which its expected speed is greatest. The regulations do not provide for variable ratings based on speed.; Finally, you ask whether cautionary labels dealing with GAWR and GVW figures may be installed in the cab. The NHTSA does not object to the use of such labels. They may be used, as appropriate, to indicate permissible use of higher loads in low-speed applications.; 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.