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: aiam4949OpenMr. Woodruff Carroll Carroll, Carroll, Davidson, & Young The White Memorial Building Suite 206 100 East Washington St. Syracuse, NY 13202; Mr. Woodruff Carroll Carroll Carroll Davidson & Young The White Memorial Building Suite 206 100 East Washington St. Syracuse NY 13202; "Dear Mr. Carroll: This responds to your letter inquiring about ho NHTSA's regulations relate to snowplows. Ms. Kathleen DeMeter, the Assistant Chief Counsel for General Law, has already responded to your Freedom of Information request in a letter dated January 6, 1992. I am pleased to have this opportunity to further explain our regulations to you. By way of background information, the National Traffic and Motor Vehicle Safety Act (the Safety Act, 15 U.S.C. 1392) authorizes this agency to issue Federal motor vehicle safety standards that set performance requirements for new motor vehicles and new items of motor vehicle equipment. A snow plow that is designed and intended to be attached to a motor vehicle would be considered an item of motor vehicle equipment, within the meaning of the Safety Act. However, NHTSA has not issued any specific standards setting forth performance requirements for snow plows. While there are no safety standards directly applicable to snow plows, the following circumstances are relevant to equipping motor vehicles with snow plows. If before the first consumer purchase, the original equipment manufacturer or an alterer equips a motor vehicle with a snow plow, the manufacturer or alterer must certify that the vehicle complies with the applicable safety standards when equipped with the snow plow. This leads to the question of what conditions would be used to determine if the vehicle complies with the applicable safety standards when equipped with a snow plow. This question is answered in the definition of 'unloaded vehicle weight' set forth in 49 CFR 571.3. 'Unloaded vehicle weight,' which is used to determine a vehicle's gross vehicle weight rating for the purposes of the tire and braking standards and to specify the test conditions for NHTSA's crash testing standards, is defined as 'the weight of a vehicle with maximum capacity of all fluids necessary for operation of the vehicle, but without cargo, occupants, or accessories that are ordinarily removed from the vehicle when they are not in use.' Thus, those parts of the snow plow which are permanently attached to the vehicle and any snow plow parts that are not ordinarily removed from the vehicle would be in place and their weight would be considered in determining compliance with applicable standards. However, the snow plow blade and any other parts of the snow plow that are ordinarily removed when the snow plow is not in use would not be attached to the vehicle and the weight of these parts would not be considered in determining compliance with the applicable safety standards. Another relevant provision of Federal law with respect to equipping a vehicle with a snow plow is 108(a)(2)(A) of the Safety Act (15 U.S.C. 1397(a)(2)(A)), which specifies that, 'no manufacturer, distributor, dealer, or motor vehicle repair business shall knowingly render inoperative, in whole or in part, any device or element of design installed on or in a motor vehicle or item of motor vehicle equipment in compliance with an applicable Federal motor vehicle safety standard.' If a manufacturer, distributor, dealer, or motor vehicle repair business added a snow plow to a motor vehicle in such a way that any of the elements of design installed on the vehicle in compliance with a safety standard were 'rendered inoperative,' that entity would have violated the Safety Act. This agency also has authority to investigate allegations that motor vehicles and items of motor vehicle equipment contain defects related to motor vehicle safety, and to order the manufacturer to notify owners and to remedy without charge any vehicles or items of equipment determined to contain a defect related to motor vehicle safety, as provided in sections 151-160 of the Safety Act (15 U.S.C. 1411-1420.) If there were indications that any snow plows contained a defect related to motor vehicle safety, the agency would investigate and take appropriate action. Of course, as with any investigation of alleged safety-related defects, the outcome would depend on the facts of the specific investigation. 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: aiam2464OpenMr. John J. Giesguth, Director, Bureau of Pupil Transportation, Division of Field Services, Department of Education, P.O. Box 2019, Trenton, New Jersey 08625; Mr. John J. Giesguth Director Bureau of Pupil Transportation Division of Field Services Department of Education P.O. Box 2019 Trenton New Jersey 08625; Dear Mr. Giesguth: This is in reply to your letter of September 9, 1976, requestin information of the legal aspects of the change in the definition of 'school bus.'; Effective April 1, 1977, the definition of 'school bus' in Title 49 o the Code of Federal Regulation (49 CFR S571.3) will read as follows:; >>>'School bus' means a bus that is sold or introduced in interstat commerce, for purposes that include carrying students to and from school or related events, but does not include a bus designed and sold for operating as a common carrier in urban transportation.<<<; The definition of 'bus' will continue to read a follows: >>>'Bus' means a motor vehicle with motive power, except a trailer designed for carrying more than 10 persons.<<<; The new definition of school bus will include many of the van-typ vehicles that are classified as Type II school vehicles under Highway Safety Program Standard No. 17. If a Type II van is designed to carry more than 10 persons, and if it is sold for purposes that include 'carrying students to and from school or related events,' it will have to be sold with all the equipment specified for school buses by the Federal Motor Vehicle Safety Standards. It will therefore have to have school bus lights as specified by the standard on lighting (49 CFR S571.108).; Our experience with the comparative accident patterns of Type I an Type II buses does not justify the use of different lighting systems for the two types. In view of Congress's expressed desire to have the school bus standards uniformly applicable to busses of all sizes, we consider it appropriate to apply the lighting standard to all school buses.; We understand your concern with the effects that the newly applicabl requirements will have on your purchase of Type II vans. However, we are persuaded that the requirements are reasonable and that they will protect school children.; If we can be of further assistance, please let us know. Sincerely, John W. Snow, Administrator |
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ID: aiam0459OpenMr. Robin A. C. Dandy, Senior Engineer, Head of Mechanical Section, British Standards Institution, Hemel Hempstead Centre, Marylands Avenue, Hemel Hempstead, Herts, England; Mr. Robin A. C. Dandy Senior Engineer Head of Mechanical Section British Standards Institution Hemel Hempstead Centre Marylands Avenue Hemel Hempstead Herts England; Dear Mr. Dandy: Your letter of 4 October 1971 encloses drawings of several seat bel buckle installations that show the locations at which you propose to apply the buckle crush forces specified in Standard No. 209. As to each of the buckles depicted, we consider the force lines to be correctly drawn for purposes of the buckle crush test.; Please advise us if we can be of further assistance. Sincerely, Lawrence R. Schneider, Chief Counsel |
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ID: aiam2034OpenMr. H. Melvin Strand, President, Duo-matic Importers LTD., P.O. Box 1436, Colorado Springs, CO 80901; Mr. H. Melvin Strand President Duo-matic Importers LTD. P.O. Box 1436 Colorado Springs CO 80901; Dear Mr. Strand: This responds to Duo-matic's August 19, 1975, question whether Standar No. 121, *Air Brake Systems*, applies to an air brake coupler device that connects air brake hoses from a truck to the trailer it tows.; The answer to your question is no. Paragraph S3 (Applicability) o Standard No. 121 states that the standard applies to trucks, buses, and trailers equipped with air brake systems (with some stated exceptions). The standard therefore applies only to vehicles, and does not apply to motor vehicle equipment such as the Duo-matic coupler device.; Sincerely, Frank Berndt, Acting Chief Counsel |
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ID: aiam0009OpenMr. Andy Tanner Glas-Weld of Jacksonville, Inc. 7901 Baymeadows Way, Suite #14 Jacksonville, Florida 32257; Mr. Andy Tanner Glas-Weld of Jacksonville Inc. 7901 Baymeadows Way Suite #14 Jacksonville Florida 32257; "Dear Mr. Tanner: This responds to your letter regarding labeling o glazing materials. You explained that your company restores marred bus windows and renders them in like-new condition in accordance with the ANSI Z26.1 standards. You asked if your 'remanufactured' windows must indicate the materials manufacturer or whether a 'generic designation which would exclude the origination information' would be acceptable. You also asked whether, if the windows are basically unchanged, you could keep the original labeling or must instead restate the 'unaltered properties' in your own labeling. Some background information about the agency may be useful. NHTSA has the authority under the National Traffic and Motor Vehicle Safety Act (15 U.S.C. 1397(a)(2)(A), 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). Based on the information provided in your letter, your company would not be considered a 'manufacturer' of new glazing material under agency regulations. You stated that your company restores or reconditions marred bus window glazing to a like-new condition. The agency has previously determined that reconditioners need not certify that reconditioned motor vehicles or motor vehicle equipment comply with the safety standards that apply only to new motor vehicles or new motor vehicle equipment. In your case, the reconditioned glazing is considered to be the same glazing as originally manufactured. However, your company would be affected by section 108(a)(2)(A) of the Safety Act . That section prohibits any manufacturer, distributor, dealer, or motor vehicle repair business from 'render ing inoperative' any equipment or element of design installed in compliance with a Federal safety standard. 'Render inoperative' means to remove, disconnect or degrade the performance of a system or element of design installed pursuant to Federal safety standards. The 'render inoperative' provision of the law means that you are not allowed to recondition or restore glazing if that restoration would cause the glazing to no longer comply with the applicable requirements of Standard No. 205. To comply with the obligations imposed by this 'render inoperative' provision, you should examine the glazing you 'restore' to determine whether the glazing continues to comply with Standard No. 205. Section S6 of Standard No. 205 sets forth the certification and marking requirements for glazing materials. The standard also 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. As a repair business, you must ensure that the reconditioned glazing continues to be marked in accordance with ANSI Z26.1. ANS Z26.1 requires that all glazing be marked with a a DOT code mark, a unique number assigned by the agency to identify each prime glazing material manufacturer. The DOT code mark is used in defect or noncompliance recall campaigns to identify the manufacturer. In addition, ANS Z26.1 requires that all glazing have the distinctive designation or trademark of the prime glazing material manufacturer. However, NHTSA has previously concluded that the designation or trademark on the glazing need not be that of the prime glazing material manufacturer, if the glazing is marked with the prime glazing material manufacturer's DOT code mark (Letter to Terry E. Quinn, May 31, 1988). NHTSA can easily and accurately identify the prime glazing material manufacturer from the DOT code mark, regardless of the distinctive designation or trademark that appears on the glazing. Thus, if the original prime glazing material manufacturer's DOT code mark remains on the glazing material, you may either use the prime glazing material manufacturer's or your own distinctive designation or trademark. You may not, however, use a 'generic designation' that does not have a distinctive designation or trademark. Because, as stated above, reconditioned glazing is considered to be the same glazing as originally manufactured, you may keep the original ANS Z26.1 marking and need not restate the unaltered properties in your own labeling. However, if the existing DOT code mark is removed during reconditioning, you must re-mark the glazing in accordance with the original mark. The agency has previously determined that removal of a DOT identification number from a tire is considered rendering inoperative an element of design of the tire (Letter to Jeffrey Libman, January 21, 1980). Like the DOT code mark for glazing, the DOT identification number is used in defect or noncompliance recall campaigns. Thus, the agency considers the removal of a DOT code mark from a piece of glazing to be the rendering inoperative an element of design of the glazing. I hope that this information is helpful. If you have any further questions or need additional information about this topic, please feel free to contact Mr. John Rigby of this office at the above address or by telephone at (202) 366-2992. Sincerely, Paul Jackson Rice Chief Counsel"; |
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ID: aiam4733OpenMr. Suichi Watanabe General Manager Automotive Lighting Engineering Control Department Stanley Electric Co., Ltd. 2-9-13, Nakameguro, Meguro-ku Tokyo 153, Japan; Mr. Suichi Watanabe General Manager Automotive Lighting Engineering Control Department Stanley Electric Co. Ltd. 2-9-13 Nakameguro Meguro-ku Tokyo 153 Japan; Dear Mr. Watanabe: This is in reply to your letter of March 19, 1990 asking whether a new combination rear lamp is permitted under Motor Vehicle Safety Standard No. 108. The lamp consists of three compartments. In its normal operating mode, when the taillamp and/or stop lamp are activated, all three compartments show a red light. Your question arises with respect to three different operating modes. The first occurs when the turn signal is activated, the red light in one of the compartments is replaced by an amber flashing one. The second occurs when the backup lamp is activated, the red light in another of the compartments is replaced by a white steady-burning one. The third occurs when both the backup lamp and turn signal are activated, in this event, the combination lamp would present an amber flashing light, a red steady-burning one, and a white steady-burning one. You have informed us that 'the requirement of photometric and lighted area for each lamp function comply to FMVSS No. 108 and related SAE Standards.' Further, as for the stop and taillamp functions, they comply with requirements for one and three compartment lamps when operating with one or three compartments (we assume that they would also meet the requirements for two compartment lamps). The lamp appears to be intended to fulfill the requirements of Standard No. 108 for turn signal, stop, tail, and backup lamps. Thus, your question appears to be whether Standard No. 108 requires separate lamps or compartments dedicated to a specific purpose, or whether your multiple purpose lamp is acceptable. Standard No. 108 does not prohibit a combination of the functions that any chamber of your lamp provides. When a specific function is activated, the lamp will perform that particular function in a manner that appears to meet the minimum standard established by Standard No. 108. Assuming that the CIE color definitions for white, amber, and red are met by the backup, turn, and stop/tail functions, the lamp appears to be permissible under Standard No. 108. Sincerely, Stephen P. Wood Acting Chief Counsel; |
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ID: aiam1531OpenMr. Rick Shue,Product Safety Engineer,Product Engineering and Development,Volvo of America Corporation,Rockleigh, New Jersey 07647; Mr. Rick Shue Product Safety Engineer Product Engineering and Development Volvo of America Corporation Rockleigh New Jersey 07647; Dear Mr. Shue:#This responds to your April 26,1974 question whethe labeling information on hose installed in vehicles must remain legible after the vehicle is painted, and what 'permanently labeled' means in S5.2.2.#The answer of the question of painting over label information will be answered in our upcoming notice in response to petitions for reconsideration of the amendments we have made to the standard.#'Permanently labeled' means affixed in such a manner that it is not easily removable, and is reasonably designed to remain affixed and legible for the normal life of the component.#Yours truly,Richard B. Dyson,Assistant Chief Counsel; |
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ID: aiam4363OpenMr. Melvin H. Smith, Governor's Representative for Highway Safety, Illinois Department of Transportation, 2300 S. Dirksen Parkway, Springfield, IL 62764; Mr. Melvin H. Smith Governor's Representative for Highway Safety Illinois Department of Transportation 2300 S. Dirksen Parkway Springfield IL 62764; Dear Mr. Smith: This responds to your June 9, 1987, letter to me asking whether Sectio 103(d) of the National Traffic and Motor Vehicle Safety Act.; I have enclosed a copy of a March 23, 1976, letter to Mr. Marti Chauvin relating to the preemptive effect of Federal law over a New York State law for 28-inch high seat backs. Please note the discussion in the Chauvin letter relating to State requirements for additional safety features in *public school buses.* under Section 103(d), a State may require a seat back height higher than 20 inches for its public school buses, provided that the vehicles continue to comply with all applicable Federal safety standards.; I will send a copy of this letter to Mr. Larry Wort of your Department whose earlier letter to us asking about our requirements for seat back height and restraining barriers raised also the same preemption issues. Please feel free to contact my office if you have further questions.; Sincerely, Erika Z. Jones, Chief Counsel |
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ID: aiam1161OpenMr. R. W. Harvey, Peterbilt Motor Truck Co., 300 Toland Street, San Francisco, CA 94124; Mr. R. W. Harvey Peterbilt Motor Truck Co. 300 Toland Street San Francisco CA 94124; Dear Mr. Harvey: This is in reply to your letter of May 22, 1973, in which you state yo are a distributor of Peterbilt trucks and ask whether certain operations you perform subject you to Federal requirements. These operations are modifications to air brake systems and the installation of used bodies on new truck chassis.; A company whose business includes the installation of used bodies o new truck chassis is a manufacturer under the National Traffic and Motor Vehicle Safety Act and, as such, has certain responsibilities under the Act and regulations issued by this agency. In response to your question regarding registration, you are required pursuant to NHTSA 'Manufacturers' Identification' regulations (49 CFR Part 566) to submit to the agency information regarding the manufacturing operations of your company and the types of vehicles that it manufacturers.; A manufacturer is also required, pursuant to NHTSA 'Certification regulations (49 CFR Part 567, 568) to ascertain and certify the conformity of each vehicle he manufacturers to applicable motor vehicle safety standards. Under these regulations the person who completes the vehicle (the 'final-stage manufacturer') is required to affix to the vehicle a label that contains the certification that the vehicle conforms to applicable standards, as well as other information. Our experience has been that most manufacturers who install truck bodies onto new chassis are final-stage manufacturers, who must affix this label. Persons whose manufacturing operations precede that of the final-stage manufacturer are required to provide documentation with the vehicle that indicates what steps will be necessary in order to bring the vehicle into conformity with applicable standards. You also ask if there are requirements for the making of periodic reports. NHTSA 'Defect Reports' regulations (49 CFR S 573.5(b)) do require manufacturers to furnish the NHTSA with quarterly production figures.; The other operation you describe is the modification of vehicle ai brake systems, including changes in valves, lines, spring brakes, air tanks, etc. If you merely modify an existing air brake system, there are presently no certification or reporting requirements applicable to you. The NHTSA has just issued certification requirements for persons who alter completed vehicles, and depending on the extent of the modification you perform, these requirements may apply to you. They are effective February 1, 1974. All trucks manufactured after September 1, 1974, that are manufactured with air brakes will be required to conform to requirements specified in Federal Motor Vehicle Safety Standard No. 121. The law would not allow you to modify the air brake system of any truck manufactured on or after that date, before the sale of the truck to a purchaser for a purpose other than resale (a user), if the modification you performed would cause the vehicle to no longer comply with the standard.; I have only summarized the requirements that, based on the facts yo have provided, would be applicable to you. Your responsibilities are stated specifically in the regulations we have referred to, and you may obtain copies of these requirements as indicated on the enclosed, 'Where to Obtain Motor Vehicle Safety Standards and Regulations.'; Yours truly, Richard B. Dyson, Assistant Chief Counsel |
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ID: aiam4699OpenMr. Jim Evans Quality Control Department The Bargman Company 129 Industrial Avenue Coldwater, MI 49036; Mr. Jim Evans Quality Control Department The Bargman Company 129 Industrial Avenue Coldwater MI 49036; Dear Mr. Evans: This is in reply to your letter of December 13, 1989 with respect to whether the installation of 'yellow' reflex reflectors on the rear of motor vehicles is permissible under Standard No. 108. Because the standard uses the term 'amber' instead of 'yellow', I shall refer to yellow as amber also. As you note, the standard requires two red reflex reflectors to be mounted on the rear, but is silent as to whether additional reflectors, amber in color, are permitted. One of your customers has asked you to manufacture an amber turn signal lens that would have an amber reflex reflector area around the outer edge. The turn signal lamp would be adjacent to a lamp of apparently identical size and shape with a red lens and reflex reflector area, providing stop and tail lamp functions. The State of Michigan apparently allows only red reflex reflectors on the rear. You have asked whether reflectors of other colors may be mounted on the rear as long as the required red ones are present, and if it is illegal, whether Standard No. 108 may be amended to eliminate the confusion. Because an amber reflector is not a required item of lighting equipment that Standard No. 108 specifies to be installed on the rear of a motor vehicle, its acceptability is subject to the general provisions of section S5.1.3. This states, in pertinent part, that no additional reflective device may be installed that impairs the effectiveness of lighting equipment required by Standard No. 108. It does not appear to us that an amber taillamp lens with an amber reflector would create an impairment. Under Standard No. 108, amber is a permissible color for rear turn signal lamps, and its presence on a reflector surrounding the lamp should not create confusion. Therefore, manufacture, sale, and installation of an amber taillamp lens with an amber reflector would not constitute a noncompliance with Standard No. 108. However, an interpretation by NHTSA that its lighting standard does not forbid the installation of an amber reflex reflector does not mean that a State could not adopt and enforce a law prohibiting such a reflector. Under section l03(d) of the National Traffic and Motor Vehicle Safety Act, a State may impose its own safety requirements covering any aspect of performance that is not covered by Standard No. 108. We construe this provision narrowly, as allowing a State to regulate all lighting equipment that is not specifically required by Standard No. 108. Noting that Section CI 257.691 of the Micigan vehicle lighting code that you enclosed specifies that reflectors 'mounted on the rear shall reflect a red color to the rear', the appropriate remedy would be to seek an amendment of the Michigan law. This agency presently has no plans to specify yellow as an alternate color for rear reflex reflectors. Sincerely, Stephen P. Wood Acting 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.