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 |
|---|---|
ID: 0789bOpen Mr. Jeffrey Echt Dear Mr. Echt: We have received your letter of March 10, 1995, asking whether it is permissible under Standard No. 108 to use the hazard warning lamps as a deceleration warning system. Paragraph S5.5.10(a) states that "Turn signal lamps, hazard warning signal lamps, and school bus warning lamps shall be wired to flash." With this in mind, "and the fact that hazard warning indicators are commonly used to warn high-speed trailing traffic that a leading vehicle or vehicles are moving slowly or stopped", you have asked: "1. Would a device which automatically activated a vehicle's hazard warning system at the onset of high, braking induced deceleration and deactivated the hazard warning system upon release of the brake pedal (following automatic activation) be permissible under FMVSS 108? This assumes that the device will not prevent activation or cause deactivation of the hazard warning system if the mandatory vehicular hazard warning signal operating unit has been activated by the driver." Heretofore, the agency's opinion letters on deceleration warning systems have covered those that operate through lamps that are steady burning in use (to Norman H. Dankert on June 3, 1990, and to Bob Abernethy on September 7, 1990), or through original equipment lamps that are additional to those required by the standard (letter of July 30, 1993, to the Commonwealth of Virginia). In those instances, we have advised that a deceleration warning system must be steady burning in use. Your question raises the issue of whether a flashing deceleration warning system is acceptable if it operates through original equipment lamps that are intended to flash when they are used. Flexible asked a similar question with respect to a supplementary lighting system. We advised it (letter of December 8, 1986) that simultaneous use of flashing and steady-burning lamps have the potential for creating confusion in vehicles to the rear and impairing the effectivess of the required stop lamps within the meaning of S5.1.3 (the provision of Standard No. 108 that governs the permissibility of supplemental original lighting equipment). We believe that the same conclusion also applies to wiring the hazard warning system to operate as a high deceleration warning system as well. Thus, we do not view this system as permissible under Standard No. 108. Obviously, complying vehicles are manufactured so that it is possible for a driver to simultaneously activate the hazard warning system and stop lamp system. However, we believe that this happens infrequently, and when it does, it is a conscious choice of the operator and not of a system. Because of the conclusion we have reached above, your second question is moot. Sincerely,
Philip R. Recht Acting Chief Counsel ref:108 d:4/24/95
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1995 |
ID: 1989yOpen Mr. Bradley J. Baker Dear Mr. Baker: This is in reply to your letter to Taylor Vinson of this Office, with reference to a product your company manufactures, a "car dolly used to tow a vehicle behind motor homes." You question whether the dolly is a motor vehicle, and if so, whether identification lamps are necessary for it. I regret the delay in responding. The car dolly appears to be a vehicle drawn by mechanical power manufactured primarily for use on the public roads, and thus a "motor vehicle" subject to the jurisdiction of this agency. Specifically, it would be a "trailer", since it is a motor vehicle without motive power, designed for carrying property and for being drawn by another motor vehicle. Federal Motor Vehicle Safety Standard No. l08, Lamps, Reflective Devices, and Associated Equipment, requires identification lamps on all trailers whose overall width is 80 inches or more. Therefore, if the overall width of your dolly is less than 80 inches, it need not be equipped with identification lamps. Sincerely,
Stephen P. Wood Acting Chief Counsel / Ref:l08 d:8/3l/89 |
1970 |
ID: nht95-3.47OpenTYPE: INTERPRETATION-NHTSA DATE: July 18, 1995 FROM: John Womack -- Acting Chief Counsel, NHTSA TO: Yoshiaki Matsui -- Manager, Automotive Equipment, Legal & Homologation Section, Stanley Electric Co., Ltd. TITLE: NONE ATTACHMT: ATTACHED TO 06/23/95 LETTER FROM YOSHIAKI MATSUI TO CHIEF COUNSEL (OCC 11017) TEXT: Dear Mr. Matsui: This responds to your letter of June 23, 1995, asking questions about neon high mounted stop lamps. The National Highway Traffic Safety Administration answered these questions in the preamble to a notice of proposed rulemaking that was published on June 19, 1995. We assume that you had not received it by the 23rd, and enclose a copy for your informati on. You will see (center column, page 31940) that Federal Motor Vehicle Safety Standard (FMVSS) No. 108 allows neon tubes as light sources for the center highmounted lamp. Under our interpretation of paragraph S5.1.1.16, FMVSS No. 108 also allows testing of a neon lamp with or without its ballast, in accordance with the directions of that paragraph. If you have any questions, you may refer them to Taylor Vinson of this Office. |
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ID: nht95-5.26OpenTYPE: INTERPRETATION-NHTSA DATE: July 18, 1995 FROM: John Womack -- Acting Chief Counsel, NHTSA TO: Yoshiaki Matsui -- Manager, Automotive Equipment, Legal & Homologation Section, Stanley Electric Co., Ltd. TITLE: NONE ATTACHMT: ATTACHED TO 06/23/95 LETTER FROM YOSHIAKI MATSUI TO CHIEF COUNSEL (OCC 11017) TEXT: Dear Mr. Matsui: This responds to your letter of June 23, 1995, asking questions about neon high mounted stop lamps. The National Highway Traffic Safety Administration answered these questions in the preamble to a notice of proposed rulemaking that was published on June 19, 1995. We assume that you had not received it by the 23rd, and enclose a copy for your information. You will see (center column, page 31940) that Federal Motor Vehicle Safety Standard (FMVSS) No. 108 allows neon tubes as light sources for the center highmounted lamp. Under our interpretation of paragraph S5.1.1.16, FMVSS No. 108 also allows testing of a neon lamp with or without its ballast, in accordance with the directions of that paragraph. If you have any questions, you may refer them to Taylor Vinson of this Office. |
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ID: GF007915OpenMr. Derek Dean Dear Mr. Dean: This responds to your e-mail regarding various issues related to aftermarket brake pads. The issues raised by your letter are addressed below. By way of background, the National Highway Traffic Safety Administration (NHTSA) issues safety standards applicable to new motor vehicles and new items of motor vehicle equipment. NHTSA does not provide approvals of motor vehicles or motor vehicle equipment. Under 49 U.S.C. Chapter 301, manufacturers are required to certify that their vehicles and equipment meet applicable requirements. First, you ask about Federal motor vehicle safety standards (FMVSSs) applicable to brake pads on new vehicles, as well as aftermarket brake pads. There is no Federal motor vehicle safety standard (FMVSS) specifically applicable to new brake pads. Instead, several FMVSSs regulate entire brake systems. Specifically, Standards No. 105, 121, 122, and 135 regulate brake systems for various types of motor vehicles. Vehicle manufacturers are responsible for certifying that their vehicles comply with all applicable FMVSSs, including relevant brake system requirements. Accordingly, brake pad manufacturers are not directly responsible for any certification requirements. Although NHTSA does not directly regulate brake pads, any brake pad designed to be used on a motor vehicle is an item of "motor vehicle equipment" and is subject to the notification and remedy (recall) provisions of 49 U.S.C. 30118-30120. If a manufacturer or NHTSA determines that the product contains a safety-related defect, the manufacturer is responsible for notifying purchasers of the defective vehicle or item of motor vehicle equipment and remedying the problem free of charge. Thus, defective aftermarket brake pads could be subject to our recall provisions. In you letter, you discuss the obligations of repair businesses. Although our regulations do not address brake pad replacement procedures, we note that states may regulate repair businesses and how they perform their work. In your letter, you ask about NHTSA research related to brake quality and causation of rear impact crashes, and about complaints pertaining to poorly performing brake pads. We note that NHTSA conducts various research projects related to braking performance, and our Office of Defects Investigations maintains a publicly accessible database of complaints filed with NHTSA. We suggest that you visit our web site at www.NHTSA.gov, where you may be able to find helpful information pertaining to your questions. Finally, you ask for our opinion on the "D3EA certification that GM has voluntarily adopted for use on DuraStop our Aftermarket Brake line to help ensure our brake parts do indeed keep the vehicle in compliance with the FMVSS". As discussed above, NHTSA does not provide approvals or endorsement for motor vehicle equipment. I hope this information is helpful. If you need further assistance, please contact George Feygin of my staff at this address or at (202) 366-2992. Sincerely, Jacqueline Glassman ref:105 |
2005 |
ID: 1017Open Mr. Yoshiaki Matsui Dear Mr. Matsui: This responds to your letter of June 23, 1995, asking questions about neon high mounted stop lamps. The National Highway Traffic Safety Administration answered these questions in the preamble to a notice of proposed rulemaking that was published on June 19, 1995. We assume that you had not received it by the 23rd, and enclose a copy for your information. You will see (center column, page 31940) that Federal Motor Vehicle Safety Standard (FMVSS) No. 108 allows neon tubes as light sources for the center highmounted lamp. Under our interpretation of paragraph S5.1.1.16, FMVSS No. 108 also allows testing of a neon lamp with or without its ballast, in accordance with the directions of that paragraph. If you have any questions, you may refer them to Taylor Vinson of this Office. Sincerely,
John Womack Acting Chief Counsel ref:108 d:7/18/95
|
1995 |
ID: 2112yOpen Mr. Wolfred Freeman Dear Mr. Freeman: This is in reply to your letter to June 22, l989, to the Administrator-Designate, General Curry, in which you "petition...for permission to produce a color coded (Green-Amber-Red) rear light device for all types of motor vehicles." You have designed "a workable auxiliary system that can be adopted to cars and trucks on the road." We are treating your letter as a request for an interpretation of whether your device would be permissible for sale and use as an item of aftermarket equipment under the regulations and statutes administered by this agency. By aftermarket, we mean sale of the device for installation on cars and trucks in use, as contrasted with sales by dealers for installation on new cars. The principal regulation of this agency pertaining to motor vehicle lighting equipment is Federal Motor Vehicle Safety Standard No. l08. The only requirements it establishes for the aftermarket is for equipment that is intended to replace the original lighting equipment specified by the standard (for example, headlamps and stop lamps). As your device is not a required item of motor vehicle lighting equipment, there is no Federal standard that applies to it. However, the National Traffic and Motor Vehicle Safety Act has a direct relationship to the acceptability of aftermarket equipment. The Act prohibits modifications by persons other than the owner of the vehicle if they render inoperative, in whole or in part, equipment that is installed pursuant to a safety standard. Under Standard No. l08, this equipment includes stop lamps, turn signal lamps, hazard warning signals, turn signals, backup lamps, taillamps, and the license plate lamp. On large trucks, it also includes identification lamps and clearance lamps. If the potential effect of an auxiliary lighting device is to create confusion as to the intended message of any lighting device required by Standard No. l08, we regard the auxiliary light as having rendered the required lamp partially inoperative within the prohibition of the Act. Thus, the question is whether your device has the potential to create confusion so that its installation by a manufacturer, distributor, dealer, or motor vehicle repair business would be a violation of the Act. We do not conclude that the device has this potential. In your device, a steady-burning amber light would signal that the accelerator had been released (and that neither the accelerator nor brake pedal were being applied). Amber is the recognized signal for caution. This signal will extinguish when either the accelerator (green signal) or brake pedal (red signal) is applied. Furthermore, it is steady burning whereas other rear lamps where amber is an optional color (turn signals and hazard warning signals) flash in operation. Therefore, it does not appear that your device would create confusion with required items of lighting equipment. You must also consider whether the device would be acceptable under the laws of any State where it is sold and used. We are unable to advise you on State laws, and recommend that you contact the American Association of Motor Vehicle Administrators, 4600 Wilson Boulevard, Arlington, Va. 22203. However, we believe that in several Western States, there has been specific legislation that would permit your device. We appreciate your interest in enhancing vehicle safety through improvement in rear lighting systems. We believe that improvements, such as the center highmounted stop lamp, should be introduced as standardized, mandatory lighting equipment on vehicles, rather than as optional aftermarket devices. Contrary to your understanding, our studies of a system similar to yours showed no discernible improvement in reaction time or accident avoidance over current systems. Sincerely, Stephen P. Wood Acting Chief Counsel ref:VSA#l08 d:ll/6/89 |
1970 |
ID: 11422WKMOpen Clifford C. Sharpe, Esq. Dear Mr. Sharpe: This responds to your letter to the Department of Transportation, Legal Division, which was forwarded to this agency for reply. You asked whether there are regulations addressing the sale as new of a tire that was manufactured five years previously, and whether we are aware of any studies or information regarding the effects of aging on an unused tire. By way of background information, the National Highway Traffic Safety Administration (NHTSA) has the authority under Chapter 301 of Title 49, U.S. Code, to establish Federal motor vehicle safety standards (FMVSSs) applicable to new motor vehicles and new items of motor vehicle equipment, including tires. This statute requires each person selling a new vehicle, or item of equipment covered by an FMVSS, to ensure that the new vehicle or equipment item is certified as meeting all applicable FMVSSs. Once a vehicle or item of equipment has been sold to its first retail customer, the seller's responsibility to sell a certified product terminates. See 49 U.S.C. '30112. Regulation of the sale and use of a used product becomes a matter of state jurisdiction. We understand your first question to ask whether NHTSA regulations were violated when a tire manufactured in 1986 was purchased as "new" in 1991. The answer is no. NHTSA has no regulation requiring a tire to be sold within a certain amount of time from its date of manufacture. You might wish to contact the Federal Trade Commission (FTC) for information on the appropriateness of such a sale under consumer protection regulations. The telephone number for the FTC's Bureau of Consumer Protection is (202) 326-2476. With regard to your second question, NHTSA does not have or know of any studies specifically addressing the effects of aging on a new tire. It is known, however, that heat, ultra-violet and ozone in particular can, over time, degrade rubber. Thus, although tire manufacturers blend antioxidants, antiozonants, waxes and carbon blacks with their natural rubber compounds to resist tire degradation, what is most important are the conditions under which the new tires are stored. For example, if tires are stored in direct sunlight, in extreme heat or cold, or in close proximity to air filters, the rubber in the tires will degrade faster than if they are wrapped and kept in a temperature and humidity-controlled environment. For additional reference sources, you may be interested in a comprehensive manual published under the auspices of NHTSA entitled, Mechanics of Pneumatic Tires, DOT HS 805 952, August 1981, available from Superintendent of Documents U.S. Government Printing Office Washington, D.C. 20402 (202) 783-3238 This volume is a highly detailed compilation of sources discussing every aspect of tire production. It does not specifically discuss the aging of tires once they have been manufactured, but it does discuss the various factors that contribute to the degradation of the rubber compounds in tires. In addition, you may call or write Rubber Manufacturers Association (RMA) 1400 K Street N.W. Washington, DC 20005 (202) 682-4800 The RMA is an association of various tire manufacturers and may have available some industry data on this issue. I hope this information is helpful to you. Should you have any further questions or need additional information, please feel free to contact Walter Myers of my staff at this address or at (202) 366-2992. Sincerely, Samuel J. Dubbin Chief Counsel Ref:109 d:2/2/96
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1996 |
ID: 20099.ogmOpenMr. Mark LaPlante Dear Mr. LaPlante: Please pardon the delay in responding to your letter to this office in which you asked whether the equipment that your company produces for the steel structures recoating industry is excluded from the antilock brake system (ABS) requirement of Federal Motor Vehicle Safety Standard (Standard) No. 121, Air brake systems. The answer is yes. You stated that the equipment that you manufacture is a trailer-mounted grit collection and cleaning device used to collect sandblasting grit and make it ready for re-use. The equipment in question is permanently mounted on a 40- foot single-drop fifth wheel trailer equipped with air brakes. You describe the equipment as being intended to be transported to a job site and moved only when a job is completed. Your letter further states that the trailer has a gross vehicle weight rating (GVWR) of 48,000 pounds and is not used to transport any other payload. Chapter 301 of Title 49, U.S. Code (hereinafter Safety Act) authorizes this agency to establish Federal motor vehicle safety standards applicable to new motor vehicles and new items of motor vehicle equipment. The Safety Act defines "motor vehicle" as:
49 U.S.Code 30102(a)(6). In reviewing the information you provided, assuming that the equipment in question remains stationary at job sites for an extended period of time, it is our opinion that the equipment is not a motor vehicle within the statutory definition. It is obviously designed to be used primarily off-road. Although it is portable and therefore capable of being transported on-road from the factory to the customer and by the customer from one job site to another, its on-road use is only incidental and not the primary purpose for which it was manufactured. Because it is not a motor vehicles, therefore, your equipment is not required to comply with the Federal motor vehicle safety standards, including Standard No. 121. Please note that since State laws may require the mobile equipment your company manufactures to be registered, you may wish to contact State motor vehicle administrators to determine whether there are State requirements that must be met. I hope this information is helpful to you. Should you have any further questions or need additional information, feel free to contact Otto Matheke of my staff at this address or at (202) 366-2992, fax (202) 366-3820. Sincerely, |
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ID: GF007944OpenThe Honorable Russell D. Feingold Dear Senator Feingold: Thank you for your October 7, 2004, letter on behalf of your constituent regarding bumper and lighting regulations. Specifically, your constituent is concerned about vehicle compatibility and the height of bumpers and lamps on certain vehicles. I appreciate the opportunity to address your constituents concerns. The National Highway Traffic Safety Administration (NHTSA) issues standards and regulations applicable to new motor vehicles and motor vehicle equipment. NHTSA regulates bumpers on passenger cars (49 Code of Federal Regulations (CFR) Part 581), but not on multipurpose passenger vehicles (sport utility vehicles), because such regulation could significantly reduce their utility. For vehicles subject to our bumper standards, the bumper must be located at the height of not more than 20 inches above ground. We note that the agency is very concerned with vehicle compatibility in multi-vehicle crashes. Bumper height is one of the factors affecting vehicle compatibility. In June of 2003, NHTSA published a report describing the scope of the safety problem represented by vehicle incompatibility and outlined strategies the agency plans to pursue in improving vehicle compatibility. See http://www-nrd.nhtsa.dot.gov/departments/nrd-11/aggressivity/IPTVehicleCompatibilityReport/. We have enclosed a copy of the report for your information. Currently, NHTSA and its global partners are conducting research to determine the best regulatory approaches in the area of vehicle compatibility. NHTSA is also working with vehicle manufacturers to minimize the effects of vehicle incompatibility and to develop consumer information related to this issue. With respect to headlamp location, the Federal lighting standard (49 CFR 571.108) requires that the headlamps for all new vehicles be located between 22 inches and 54 inches above the road surface. Subsequent reinstallation of headlamps at a different height by a dealer or a repair business is also prohibited. We note that the bumper and headlamp height issues raised by your constituent may not be the product of improper installation of those items, but instead may stem from raising or otherwise altering the vehicle suspension system. While this agency does not regulate suspension alterations, some states may do so. Accordingly, we suggest that your constituent contact the Wisconsin Department of Transportation, Office of General Counsel at (608) 266-8810 or ogc.exec@dot.state.wi.us to ascertain Wisconsin regulations pertaining to vehicles suspension systems, bumper height, and lighting. If you or your constituent have any further questions regarding this issue, you may contact Scott Brenner, Associate Administrator for External Affairs, at (202) 366-2566. Sincerely, Jacqueline Glassman Enclosure |
2004 |
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.