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: aiam4459OpenMr. Mike Kaizaki Manager, Truck Tire Engineering Yokohama Tire Corporation Corporate Office 60l S. Acacia Fullerton, CA 9263l; Mr. Mike Kaizaki Manager Truck Tire Engineering Yokohama Tire Corporation Corporate Office 60l S. Acacia Fullerton CA 9263l; "Dear Mr. Kaizaki: This responds to your letter requesting a interpretation of Standard No. ll9, New Pneumatic Tires for Vehicles Other Than Passenger Cars. You asked whether it is permissible to place two tire size designations, 385/65R22.5 in larger letters and l5R22.5 in small letters, on the same tire. The answer to your question is no. By way of background information, the National Highway Traffic Safety Administration does not provide approvals of motor vehicles or motor vehicle equipment. Under the National Traffic and Motor Vehicle Safety Act, it is the responsibility of the manufacturer to ensure that its vehicles or equipment comply with applicable standards. The following represents our opinion based on the facts provided in your letter. The practice of labeling two tire sizes on one tire, as you requested in your letter, was once a fairly common practice and was referred to as 'dual-size markings.' Dual-size markings were a marketing effort by tire manufacturers to try to persuade consumers to change the size and/or type of tire on their vehicles, by representing that this particular tire size was an appropriate replacement for two different sizes of tires. However, the practice of using dual-size markings confused many consumers about the size of the tire on their vehicle. The only purpose of the Federally required markings on tires is to provide consumers, in a straightforward manner, with technical information necessary for the safe use and operation of the tire. The agency concluded that it was inappropriate to permit a marketing technique that was confusing many consumers to defeat the purpose of the required markings on tires. Accordingly, dual-size markings were expressly prohibited for passenger car tires subject to Standard No. 109, 36 FR 1195, January 26, 1971. The marking requirements for tires subject to Standard No. 119 are set forth in section S6.5 of the standard. Section S6.5(c) requires that each tire be marked on both sidewalls with 'the tire size designation as listed in the documents and publications designated in S5.1.' Section S5.1 of Standard No. 119 requires each tire manufacturer to ensure that a listing of the rims that may be used with each tire the manufacturer produces is available to the public. This may be done either by the individual manufacturer furnishing a document to each of its dealers, to this agency, and to any person upon request, or the manufacturer may rely on the tire and rim matching information published by certain standardization organizations. While Standard No. 119 does not expressly prohibit dual-size markings, section S6.5(c) uses the singular when it refers to the 'tire size designation' to be labeled on the tire. Considering the past history associated with dual-size markings, this agency interprets section S6.5(c) of Standard No. 119 as prohibiting a manufacturer from marking a tire with two different size designations, even if a document or publication designated in S5.1 were to show two different size designations for the same tire size. Sincerely, Erika Z. Jones Chief Counsel"; |
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ID: aiam3666OpenMs. Linda Anderson, 1611 Mechanic Street, Doylestown, PA 18901; Ms. Linda Anderson 1611 Mechanic Street Doylestown PA 18901; Dear Ms. Anderson: This responds to your November 21, 1982, letter and subsequent Januar 12, 1983, letter submitting supplementary information concerning a play tray that you want to produce. You ask in general whether that tray would be required to comply with any of the requirements applicable to child seating systems in Standard No. 213, *Child Restraint Systems*. In a conversation that you had with Mr. Roger Tilton of my staff, you indicated that you no longer need information relating to the first two questions raised in your November letter. Accordingly, we will focus on the other issues that you raised.; The play tray that you describe would be attached to a child seat b the use of velcro fasteners secured around the restraint belts of the child seat. You state that the restraints would have to be in their proper position before the tray, which itself is not designed as a restraint, could be attached. You ask whether a manufacturer of a child seat could sell such a tray as a part of its child seating system or whether it could be marketed separately.; If the play tray were marketed as part of a child seat, it would b required to comply with all of the requirements of the standard applicable to child seats. Section S5.2.2.2 prohibits any fixed or moveable surfaces in front of the child except for surfaces that adequately restrain the test dummy in the 20 mph test. If the tray attached to the child restraint so that it is the only surface in front of the child, the child restraint would have to be tested with just the tray as specified in Section S5.2.2.2. It does not appear likely that the tray would comply with those requirements.; If your tray is manufactured and marketed separately to consumers wh own child restraint systems, it would not be required to comply with the requirements of Standard No. 213. That standard applies to new child seating systems that are designed to restrain, seat or position children. Your tray sold by itself would not constitute a child seating system designed to restrain, seat or position children and thus would not be subject to this standard.; You should be aware, however, that your tray would be considered moto vehicle equipment. As such it would be subject to our defect authority. If it were found that a substantial number of your trays were being improperly used as the sole restraint device on a child seat by connecting the tray without using the proper seat belt restraint system, the agency might determine that this constitutes a safety-related defect. Also, this could be the source of product liability suits in the event that your tray was involved in an accident where a child is injured while improperly restrained. From our analysis of your diagrams, this type of misuse appears to be likely.; In a final question, you asked whether the regulations ever change. Th answer to that question is yes. The agency frequently amends its own regulations acting upon new information or changed safety needs. Further, the agency receives petitions from members of the public to amend its regulations. The process for submitting those petitions is outlined in Part 552 of our regulations (copy enclosed).; Sincerely, Frank Berndt, Chief Counsel |
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ID: aiam2974OpenMr. Charles D. Hylton, III, Director, Editorial Services, National Tire Dealers & Retreaders Association, Inc., 1343 L Street, N.W., Washington, DC 20005; Mr. Charles D. Hylton III Director Editorial Services National Tire Dealers & Retreaders Association Inc. 1343 L Street N.W. Washington DC 20005; Dear Mr. Hylton: This is in response to your letter of February 27, 1979, asking whethe tire dealers are responsible for supplying point-of-sale information concerning the Uniform Tire Quality Grading Standards (UTQG) (49 CFR 575.104) to prospective tire purchasers.; Subpart A of Part 575, *Consumer Information Regulations*, provides i section 575.6(c) (49 CFR 575.6(c)) that,; >>>'Each manufacturer of motor vehicles, each brand name owner o tires, and each manufacturer of tires for which there is no brand name owner shall provide for examination by prospective purchasers, at each location where its vehicles or tires are offered for sale by a person with whom the manufacturer or brand name owner has a contractual, proprietary, or other legal relationship, or by a person who has such a relationship with a distributor of the manufacturer or brand name owner concerning the vehicle or tire in question, the information specified in Subpart B of this part that is applicable to each of the vehicles or tires offered for sale at that location ...'<<<; The UTQG Standards, contained in Subpart B of Part 575, specify th information which must be furnished to prospective purchasers by vehicle manufacturers, tire manufacturers, and tire brand name owners (49 CFR 575.104(d)(1)(ii)).; Thus, the Consumer Information Regulations place the responsibility fo providing UTQG point-of-sale information to prospective tire purchasers on manufacturers and brand name owners rather than directly on tire dealers. The means by which tire manufacturers and brand name owners assure that UTQG information is provided for examination will be determined between these suppliers and their dealers and distributors.; You should also note that, in light of the 30-day stay granted by th U.S. Court of Appeals for the Sixth Circuit in the case of *B.F. Goodrich Co. v. Department of Transportation*, the effective dates for all requirements of the UTQG regulation, with the exception of paragraphs (d)(1)(i)(A) and (d)(1)(iii) (49 CFR 575.104(d)(i)(A) and (d)(1)(iii), are now March 31, 1979 for bias-ply tires and October 1, 1979 for bias- belted tires. Paragraph (d)(1)(i)(A), the sidewall molding requirement, and paragraph (d)(1)(iii), the first purchaser requirement, now become effective October 1, 1979 for bias-ply tires and March 31, 1980 for bias-belted tires.; Sincerely, Frank A. Berndt, Acting Chief Counsel |
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ID: aiam0949OpenMr. Gene L. King, Mayfair Bedding Co., 2029 Alum Rock Avenue, San Jose, CA, 95116; Mr. Gene L. King Mayfair Bedding Co. 2029 Alum Rock Avenue San Jose CA 95116; Dear Mr. King: This is in reply to your letter of October 23, 1972, concerning th application of Motor Vehicle Safety Standard No. 302, 'Flammability of Interior Materials', to house boats and tent camp trailers.; Standard No. 302 applies to passenger cars, multipurpose passenge vehicles, trucks, and buses. This does not include house boats or tent camp trailers.; Yours truly, Richard B. Dyson, Assistant Chief Counsel |
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ID: aiam3373OpenMr. R. Kawaguchi, Toyo Kogyo USA Office, 23777 Greenfield Road, Suite 462, Southfield, Mi 48075; Mr. R. Kawaguchi Toyo Kogyo USA Office 23777 Greenfield Road Suite 462 Southfield Mi 48075; Dear Mr. Kawaguchi: This is in response to your letter of October 20, 1980, concernin Federal Motor Vehicle Safety Standard No.l 115, Vehicle identification number (49 CFR 571.115).; Your question concerns the submission of horsepower data to the agenc as required by the standard (S4.5.2). On February 25, 1980, the agency published an amendment to Standard No. 115 in the Federal Register (45 FR 12255) which authorized slight variations between the engine horsepower encoded in the vehicle identification number (VIN) and the actual engine horsepower. Except in the case of motorcycles, a variance in horsepower of plus or minus 10 percent was authorized. You wish to know whether the engine horsepower data you submit to the agency should be consistent with the VIN coding, or whether you should submit the precise horsepower.; The information which must be submitted pursuant to S6.3 is tha necessary to decipher the characters contained in the VIN. Consequently, the engine horsepower submitted should represent the horsepower actually encoded in the VIN, whether or not this is the precise horsepower.; Sincerely, Frank Berndt, Chief Counsel |
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ID: aiam3689OpenMr. James E. Benson, Sales Manager, Boschung Company, Inc., 530 Armory Drive, South Holland, IL 60473; Mr. James E. Benson Sales Manager Boschung Company Inc. 530 Armory Drive South Holland IL 60473; Dear Mr. Benson: This is in reply to your letter of March 23, 1983, asking whether stop lamp is required on a Boschung vehicle which has a top speed of 16 mph. You also asked for a copy of the 'Rules for Manufacturer Standard Specs.'; The agency does not consider a vehicle, which cannot exceed 20 mph an has an abnormal configuration, to be a motor vehicle. These vehicles, typically, are highway maintenance and construction equipment, lane stripers, self-propelled pavers, sod handler, fork lift, and other similar vehicles. It would not appear, therefore, that the low-speed Boschung is a 'motor vehicle.' The question of whether it is required to have a stop lamp, therefore, is dependent upon the laws of the municipality in which it is operated.; I assume the 'Rules' you wish are the Federal motor vehicle safet standards. You should write the Superintendent of Documents, U.S. Government Printing Office, Washington, D.C. 20402, enclosing a check for $8, and ask for 'Title 49 Code of Federal Regulations Parts 400 to 999.' The safety standards are at Part 571, and you will find all other regulations in the 500 series which apply to motor vehicles and their manufacturers.; If you have any further questions, we shall be happy to answer them. Sincerely, Frank Berndt, Chief Counsel |
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ID: aiam3723OpenMr. Robert J. Ainsworth, President, TOPAC International Trading Company, 325 N. Baldwin Park Blvd., City of Industry, CA 91746; Mr. Robert J. Ainsworth President TOPAC International Trading Company 325 N. Baldwin Park Blvd. City of Industry CA 91746; Dear Mr. Ainsworth: This is in response to your letter of July 12, 1983, with respect t UTQGS requirements and tires you intend to import from Shanghai, China. You have asked whether it is permissible, as an interim step to cover your initial order, if the factory affixes a label stating the traction and temperature ratings assigned to its 'Warrior' tires, subsequent tires will have this information molded into the sidewalls.; We understand from Mr. Vinson's phone conversation with you on July 2 that the tires have not been imported for sale previously and indeed are the product of a new factory which has recently opened. According to the UTQGS regulation, a tire need not have information molded into its sidewalls if it is 'a tire of a new tire line, manufactured within the first six months of production of the tire line' (49 CFR 575.104(d)(1)(i)(A)). We interpret this time frame as meaning within six months of the initial production of the tire line for export to the United States. Therefore, your initial shipment would appear to come within the exception established by the regulation.; If you have any further questions, please let us know. Sincerely, Frank Berndt, Chief Counsel |
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ID: aiam2831OpenMr. Don M. Carnahan, Supervisor, Pupil Transportation, Division of Financial Services, Office of Superintendent of Public Instruction, Old Capital Building, Olympia, WA 98504; Mr. Don M. Carnahan Supervisor Pupil Transportation Division of Financial Services Office of Superintendent of Public Instruction Old Capital Building Olympia WA 98504; Dear Mr. Carnahan: This is in reply to your letter of March 9, 1978, asking whether school bus manufacturer may install strobe lights on the top of vehicles as original equipment, without violating Federal Motor Vehicle Safety Standard No. 108. As you indicated in your letter of December 28, 1977, this would be permissible under local law.; I informed you on February 14, 1978, in requesting a clarification that legality depended on whether the additional lighting impaired the effectiveness of the required equipment. If so, paragraph S4.1.3 of Standard No. 108 would prohibit installation. The lamps in question are strobe lights, either white or amber in color, that would be used during inclement weather. We do not know whether these lights would be used while the bus is in motion, or when it is stopped and the required schoolbus warning lamps are activated. If the strobe lights are used while the vehicle is in motion, during inclement weather, we do not know whether they would impair the effectiveness of the stop lamps by distracting the attention of a driver following the bus. If the light of the strobe lamp is white, and the light operates while the vehicle is at rest and its red or red and amber warning signals are also activated, the signals might prove confusing to other motorists. However, on the basis of the data presented, it is not possible to determine whether the strobe lamps would impair the effectiveness of the required lighting equipment within the meaning of S4.1.3. Therefore, we are willing to defer to the judgment of the State of Washington on this question, until such time, if ever, as data may be presented supporting a conclusion of impairment.; Sincerely, Joseph J. Levin, Jr., Chief Counsel |
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ID: aiam2562OpenMr. Gordon P. Cress, Chief, Structures & Test, Weber Aircraft, 2820 Ontario Street, Burbank, CA 91505; Mr. Gordon P. Cress Chief Structures & Test Weber Aircraft 2820 Ontario Street Burbank CA 91505; Dear Mr. Cress: This responds to your letter of February 25, 1977, requesting a interpretation concerning the force requirements specified in Safety Standard No. 207, *Seating Systems*, and Safety Standard No. 210, *Seat Belt Assembly Anchorages*. You ask whether the specified forces are intended to be 'limit loads' (those loads under which structural integrity must be maintained even though permanent set, yielding or permanent deformation takes place) (your terms and definitions).; Under the requirements of Standard No. 210, the anchorage of a sea belt assembly must be able to withstand certain designated forces when tested in accordance with the procedures of the standard. Paragraph S4.2.3 of Standard No. 210 provides that permanent deformation or rupture of a seat belt anchorage or its surrounding area is not considered to be a failure, if the required force is sustained for a specified period of time. Therefore, the force requirements of Standard No. 210 could be considered 'ultimate loads,' as you define that term.; The agency interprets the force requirements of Standard No. 207 t allow some deformation of the seats during the force test, provided structural integrity is maintained. Therefore, the force requirements of Standard No. 207 could also be considered 'ultimate loads,' as you define that term. Please note, however, that if seats are displaced to an extent that the agency determines occupant safety is threatened, a determination could be made under provisions of the National Traffic and Motor Vehicle Safety Act (15 U.S.C. S1381, *et seq*.) that the vehicle contains a safety related defect and sanctions could be imposed on the manufacturer.; Please contact our office if you have any further questions. Sincerely, Frank A. Berndt, Acting Chief Counsel |
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ID: aiam2098OpenMr. Frank W. Bowers, Manager, Product Reliability, General Electric Company, Nela Park, Cleveland, OH 44112; Mr. Frank W. Bowers Manager Product Reliability General Electric Company Nela Park Cleveland OH 44112; Dear Mr. Bowers: This is in reply to your letter of July 8, 1975, to Ed Leysath of thi agency concerning wattage requirements for Type 1A and 2A headlamps.; Your specific question is whether the wattage specifications in Federa Motor Vehicle Safety Standard No. 108 for Type 1A and 2A headlamps are design wattages or maximum wattages.; Paragraph S4.1.1.21(b) of Standard No. 108 specifies that, 'Each Typ 1A headlamp shall be *designed* for a maximum of 50 watts. Each Type 2A headlamp shall be *designed* for a maximum of 60 watts for each filament.' (Emphasis added.) It follows, therefore, that the 50- and 60- watt values are design wattages. You are correct in your interpretation that a tolerance of approximately 7.5% applies to these values, and that an ampere value of 4.20 for a 50-watt filament and 5.02 for a 60-watt filament is permitted. The 7.5% tolerance as you know is the average actual maximum wattage (as opposed to design wattage) rating of headlamps listed in Table 2 of SAE Standard J573 as determined by multiplication of the maximum amperage times the design volts.; Sincerely, Frank A. Berndt, 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.