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: aiam4833OpenMr. A. Kling; Mr. A. Kling; "Mr. A. Kling Hamadbik, Ltd 16, Beit Alfa St. Tel-Aviv 67219 Israe Dear Mr. Kling: This responds to your inquiry about the color coding requirements in section S5.1.14 of Federal motor vehicle safety standard No. 116, Motor vehicle brake fluids. (49 CFR 571.116). After noting that DOT 3 and DOT 4 brake fluid must be colorless to amber, you asked what is the color coding range for amber. As explained below, the agency has decided not to specify a numerical or chromatic 'range' for the color coding requirements. Instead, the appropriate method for determining compliance to the color coding requirements is through visual inspection. The purpose of the color coding requirements is to permit easy identification of fluids before they are placed in a vehicle, in order to prevent the mixing of an incompatible fluid in a braking system. At one time, the National Highway Traffic Safety Administration (NHTSA) had proposed color requirements defined in terms of millimicrons. (38 FR 32142, November 21, 1973). However, when the agency later determined that visual inspection for color compliance was adequate, the proposed wavelength bands were deleted. (39 FR 30353, August 22, 1974) In a subsequent notice, the agency explained that The specifications for fluid colors are intended to refer to color ranges as generally interpreted in daylight by persons of normal color vision. No color coordinates are proposed, since the fluids may change color in storage or in use (without detriment to the performance of the fluids). (40 FR 56928, December 5, 1975) Thus, the generally interpreted meaning for 'amber' (which is defined as 'yellowish-brown' by the Random House Dictionary of the English Language) should be used to determine if a brake fluid complies with the color coding requirements for DOT 3 and DOT 4 brake fluid. I hope this information is helpful. If you have any further questions, please feel free to contact Marvin Shaw of my staff at this address or by telephone at (202) 366-2992. Sincerely, Paul Jackson Rice Chief Counsel"; |
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ID: aiam2481OpenMr. J. W. Lawrence, Manager, Safety & Environmental Engineering, White Motor Corporation, 35129 Curtis Boulevard, Eastlake, OH 44094; Mr. J. W. Lawrence Manager Safety & Environmental Engineering White Motor Corporation 35129 Curtis Boulevard Eastlake OH 44094; Dear Mr. Lawrence: This is in reply to your letter of February 18, 1977, asking whether 4 CFR Part 577 conflicts with Section 153(c)(4) of the National Traffic and Motor Vehicle Safety Act.; Pursuant to Section 153(c)(4) notification by a manufacturer to dealer must be 'by certified mail or other more expeditious means.' On the other hand, Part 577 requires notification to be given by first class mail to the first or most recent purchaser known to the manufacturer, in your view, which could mean a dealer. You stated that the 'apparently conflicting' requirements affect the mailing of notices to dealers when they are the last known purchasers.; There is no conflict. Part 577 is a regulation for the notification o owners of vehicles, not dealers. The regulation sets forth-- 'requirements for notification to owners of motor vehicles' (577.1) and its purpose 'is to insure that notifications of defects or noncompliances adequately inform and effectively motivate owners...to have such vehicles...inspected and, when necessary, remedied as quickly as possible' (577.2). A dealer is not an 'owner' within the intent of Part 577 and a manufacturer's notification obligation to its dealers is that set out in Section 153(c)(4).; Therefore, we cannot confirm that first class mailings from manufacturer to a dealer conform to Part 577, and your letter offers no facts upon which to base a finding that first class mail is a 'more expeditious means' of dealer notification than certified mail.; Sincerely, Frank A. Berndt, Acting Chief Counsel |
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ID: aiam5550OpenMr. Donnell W. Morrison 1005 Drinnon Drive Morristown, TN 37814; Mr. Donnell W. Morrison 1005 Drinnon Drive Morristown TN 37814; Dear Mr. Morrison: This is in reply to your letter of April 25, 1995 asking for a clarification of the letter of April 10 to you from the former Chief Counsel, Philip Recht. He explained Standard No. 108's requirements for the location of rear lighting on wide vehicles. As the letter stated, identification lamps are to be mounted 'as close to the top of the vehicle as practicable.' You speak of having seen 'semitrailers on the highway with all the rear lights at bed level' including clearance and identification lamps. As the letter also stated, the determination of practicability is initially that of the manufacturer, to be made in its certification that the vehicle meets all applicable Federal motor vehicle safety standards. NHTSA will not question that determination unless it appears clearly erroneous. Without further information on the semitrailers you saw, we cannot judge whether mounting the clearance and identification lamps at bed level was a clearly erroneous determination by the trailer's manufacturer. There are some configurations where there is no header on which to mount lamps and the top of the doors approaches the top of the vehicle. In those configurations, we would not contest the manufacturer's determination that mounting the lamps at bed level was 'as close to the top of the vehicle as practicable.' On the other hand, the semitrailers you saw might have failed to conform to Standard No. 108. I hope that this clarifies the matter for you. If you have any further questions you may call Taylor Vinson of this Office (202-366-5263). Sincerely, John Womack Acting Chief Counsel; |
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ID: aiam5551OpenMr. Donnell W. Morrison 1005 Drinnon Drive Morristown, TN 37814; Mr. Donnell W. Morrison 1005 Drinnon Drive Morristown TN 37814; Dear Mr. Morrison: This is in reply to your letter of April 25, 1995 asking for a clarification of the letter of April 10 to you from the former Chief Counsel, Philip Recht. He explained Standard No. 108's requirements for the location of rear lighting on wide vehicles. As the letter stated, identification lamps are to be mounted 'as close to the top of the vehicle as practicable.' You speak of having seen 'semitrailers on the highway with all the rear lights at bed level' including clearance and identification lamps. As the letter also stated, the determination of practicability is initially that of the manufacturer, to be made in its certification that the vehicle meets all applicable Federal motor vehicle safety standards. NHTSA will not question that determination unless it appears clearly erroneous. Without further information on the semitrailers you saw, we cannot judge whether mounting the clearance and identification lamps at bed level was a clearly erroneous determination by the trailer's manufacturer. There are some configurations where there is no header on which to mount lamps and the top of the doors approaches the top of the vehicle. In those configurations, we would not contest the manufacturer's determination that mounting the lamps at bed level was 'as close to the top of the vehicle as practicable.' On the other hand, the semitrailers you saw might have failed to conform to Standard No. 108. I hope that this clarifies the matter for you. If you have any further questions you may call Taylor Vinson of this Office (202-366-5263). Sincerely, John Womack Acting Chief Counsel; |
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ID: aiam1312OpenHOLMES PONTIAC CO. INC., George D. Smith, 1322 Texas Avenue, Shreveport, LA 71101; HOLMES PONTIAC CO. INC. George D. Smith 1322 Texas Avenue Shreveport LA 71101; Dear Mr. Smith: This is in response to your letter of October 17, 1973, concerning th permissibility of installing trailer hitches on your 1974 cars without violating Federal Motor Vehicle Safety Standards.; The attachment of trailer hitches to automobile bumpers will no constitute a violation of any Federal Motor Vehicle Safety Standard. The testing requirements of Standard No. 215, which are here applicable, specify that trailer hitches are to be removed prior to testing for compliance. Thus, it is only necessary that the automobile comply with the regulation when the trailer hitch is not attached.; We appreciate your inquiry. Sincerely, Lawrence R. Schneider, Chief Counsel |
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ID: aiam2880OpenMr. James D. Carney, Executive Director, Truck Equipment & Body Distributors Association, 25900 Greenfield Road, Oak Park, MI 48237; Mr. James D. Carney Executive Director Truck Equipment & Body Distributors Association 25900 Greenfield Road Oak Park MI 48237; Dear Mr. Carney: This responds to your September 12, 1978, letter asking severa questions about the applicability of the certification regulations to various manufacturers. In particular, you want to know when a manufacturer is considered an intermediate or a final-stage manufacturer for purposes of applying the regulations.; Part 568, *Vehicles Manufactured in Two or More Stages*, clearl defines incomplete, intermediate, and final-stage manufacturers. Using those definitions, you should be able to determine the certification responsibilities of any manufacturer based upon the manufacturing operation.; From the facts described in your letter, it is not possible for th agency to state with certainty whether a body installer would be an intermediate manufacturer or a final-stage manufacturer. These classifications depend upon the type of manufacturing done by each manufacturer. If the body installer performs such operations on an incomplete vehicle, as defined in Part 568, that the vehicle becomes a completed vehicle, then the body installer would be considered a final-stage manufacturer. A completed vehicle is also defined in Part 568. A manufacturer subsequently installing a refrigeration unit would be an alterer of that vehicle. If, on the other hand, the body installer is not performing final-stage manufacturing operations, then it must certify as an intermediate manufacturer. This would occur when, for example, the vehicle was not completed in a manner enabling it to be used on the highways without some further manufacturing operations.; The National Highway Traffic Safety Administration (NHTSA) through it certification regulations is simply requiring that each manufacturer certify the compliance of the vehicle to the extent possible given its manufacturing operations. If a manufacturer makes a good faith determination that it is a certain type of manufacturer or alterer, the NHTSA is likely to accept the certification so long as the appropriate label for that type of manufacturer is attached to the vehicle in the manner prescribed by the regulations.; Sincerely, Joseph J. Levin, Jr., Chief Counsel |
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ID: aiam4889OpenMr. Richard E. Wright Richard E. Wright Associates 151 Fenwick Court Delran, NJ 08075; Mr. Richard E. Wright Richard E. Wright Associates 151 Fenwick Court Delran NJ 08075; "Dear Mr. Wright: This responds to your letter of May 3, 199 concerning the possible applicability of the Federal Motor Vehicle Safety Standards to tempered glass products in travel trailers and motor homes. I am pleased to have this opportunity to explain the situation to you. Some background information may be useful. The National Highway Traffic Safety Administration (NHTSA) has authority under the National Traffic and Motor Vehicle Safety Act (15 U.S.C. 1397(a)(2)(A), the Safety Act) to issue safety standards applicable to new motor vehicles and new items of motor vehicle equipment. Glazing, as an 'addition to the motor vehicle,' is considered to be an item of motor vehicle equipment (Section 102(4) of the Safety Act). New glazing material for use in motor vehicles is subject to the requirements of Standard No. 205, Glazing Materials (49 CFR 571.205). Standard No. 205 incorporates by reference 'ANS Z26,' the American National Standards Institute's Safety Code for Safety Glazing Materials for Glazing Motor Vehicles Operating on Land Highways. The agency has previously stated that Standard No. 205 does not apply to trailers, which our regulations define as 'a motor vehicle with or without motive power, designed for carrying persons or property and for being drawn by another motor vehicle.' Thus, the standard would not apply to travel trailers. NHTSA covers motor homes under Standard No. 205. Standard No. 205 specifies performance requirements for glazing material for use in specified locations in motor vehicles, including motor homes. The agency has previously stated that the standard establishes requirements for glazing used in windows and interior partitions in motor vehicles. Glazing used in locations other than windows and interior partitions would not be subject to the requirements of the standard. I hope that this information is useful to you. If you have further questions, please contact John Rigby of this office at 202-366-2992. Sincerely, Paul Jackson Rice Chief Counsel"; |
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ID: aiam2691OpenHonorable Hamilton Fish, Jr., House of Representatives, Washington, DC 20515; Honorable Hamilton Fish Jr. House of Representatives Washington DC 20515; Dear Mr. Fish: This is in response to your letter of August 24, 1977, forwardin correspondence from one of your constituents, Mr. Richard G. Castor, concerning an automobile accident in which he was involved.; Mr. Castor stated that he was involved in a 30 mph collision with pole, which caused considerable damage to his car. He suggested that a poorly designed bumper was responsible for the severity of the damage to his automobile.; The accident described by Mr. Castor occurred at a speed far above tha involved in the typical low speed 'fender bender' accident. If his 30 mph impact estimate is accurate it is remarkable that he was not injured and that the vehicle was capable of being repaired. No motor vehicle bumper of reasonable size and weight could possibly protect a vehicle from damage in such a high speed collision.; The National Highway Traffic Safety Administration (NHTSA) has had i effect since 1974 a safety standard that requires cars to be capable of sustaining 5 mph impacts, front and rear, without suffering damage to their various safety systems. That standard was promulgated pursuant to the National Traffic and Motor Vehicle Safety Act of 1966 (Pub. L. 89-563). The Motor Vehicle Information and Cost Savings Act of 1972 (Pub. L. 92-513) directed the agency to promulgate a bumper standard that would reduce the costs to consumers occasioned by low-speed collisions. In response to that order, the NHTSA established a standard that would prohibit damage both to safety systems and to all other surface areas of vehicles involved in low-speed collisions.; Under that standard (49 CFR Part 581, *Bumper Standard*), effectiv September 1, 1978, cars will be permitted to sustain damage only to the bumper itself when subjected to 5 mph front and rear impacts. Thirty mile- per-hour protection was not envisioned by Congress and would so increase the cost and weight of a vehicle as to make its purchase and operation unfeasible.; Your constituent's comments are appreciated. Sincerely, Joan Claybrook |
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ID: aiam4745OpenMr. Hiroshi Ozeki Executive Vice President Mazda Research & Development of North America, Inc. 1203 Woodridge Ave. Ann Arbor, MI 48105; Mr. Hiroshi Ozeki Executive Vice President Mazda Research & Development of North America Inc. 1203 Woodridge Ave. Ann Arbor MI 48105; Dear Mr. Oseki: This is in reply to your letter of April 10, l990, wit respect to the use of the hazard warning system concurrently with the stop lamps to provide additional warning to vehicles to the rear. You enclosed two interpretations of the agency which appear to be conflicting, and you have asked for a clarification. In our letter of June 16, l983, we informed Safety Alert Company that its flashing deceleration warning system could operate through any rear lighting system that Standard No. 108 allows to be used for signalling purposes, such as the turn signal or hazard warning system, provided that the color of light or photometrics required by the standard was not changed. However, in our letter of December 8, 1986, we informed Flxible Corporation that their flashing deceleration warning system was unacceptable under Standard No. 108 because 'simultaneous use of flashing (amber) and steady-burning lamps have the potential for creating confusion in vehicles to the rear of the bus, and impairing the effectiveness of the required stop lamps within the meaning of S4.1.3.' We do not believe that there is a conflict. The system described in the Safety Alert letter would utilize a vehicle's original lighting equipment that is intended to flash, and that the motoring public is accustomed to seeing flash. The system described in the Flxible letter, on the other hand, would employ a series of new lamps, not required by the standard but supplemental to the required lighting equipment, and whose presence and function would be unfamiliar to motorists following. Thus, that unfamiliar system, if flashing, could have a confusing effect, as we stated in our l986 letter. I hope that this clarifies the matter for you. Sincerely, Stephen P. Wood Acting Chief Counsel; |
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ID: aiam2279OpenMs. Constance Newman, Assistant Secretary for Consumer Affairs and Regulatory Functions, Department of Housing and Urban Development, 451 Seventh Street, S.W., Washington, DC, 20410; Ms. Constance Newman Assistant Secretary for Consumer Affairs and Regulatory Functions Department of Housing and Urban Development 451 Seventh Street S.W. Washington DC 20410; Dear Ms. Newman: I am writing in response to questions that have been raised about th National Highway Traffic Safety Administration's (NHTSA) authority to regulate mobile homes. As you may know, mobile homes have been considered to be 'motor vehicles' as that term is defined in the National Traffic and Motor Vehicle Safety Act of 1966 (15 U.S.C. 1391 et seq.) ('the Vehicle Safety Act'). As such, they have been subject to Federal Motor Vehicle Safety Standard No. 108 (*Lamps, Reflective Devices, and Associated Equipment*) and to our authority regarding the notification and remedy of noncompliances and defects related to motor vehicle safety.; The National Mobile Home Construction and Safety Standards Act of 197 (42 U.S.C. 5401 et seq.) ('the Mobile Home Act') established within the Department of Housing and Urban Development a comprehensive program for the regulation of mobile homes. We have concluded that one result of that statute's enactment was the implied repeal of the NHTSA's authority with respect to mobile homes. Accordingly, we consider that the enactment had the effect of amending the Vehicle Safety Act's definition of 'motor vehicle' to exclude 'mobile homes' as the latter term is defined in the Mobile Home Act. We are preparing a Federal Register notice that will reflect this conclusion.; Sincerely, James B. Gregory, Administrator |
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.