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: aiam4009OpenMr. Edmund Gabler, Colonial House, Apartment 507, 1150 Atlantic Shores Blvd., Hallandale, FL 33009; Mr. Edmund Gabler Colonial House Apartment 507 1150 Atlantic Shores Blvd. Hallandale FL 33009; Dear Mr. Gabler: Thank you for your letter asking about our requirements for lap belt and expressing your views on state laws requiring the proper use of safety belts. We appreciate hearing from concerned citizens on the important subject of improved motor vehicle safety.; You asked whether safety belts on your county buses are legal if thos belts are designed only as lap belts and do not restrain both the pelvic and upper torso areas of the body. The answer to your question is that those belts are permitted to be installed on buses. Some background information may be helpful. Under the National Traffic and Motor Vehicle Safety Act, this agency is authorized to issue safety standards for new motor vehicles. Our Safety Standard No. 208, *Occupant Crash Protection*, requires installation of safety belts in new motor vehicles.; Our belt installation requirements vary according to the type o vehicle. For large 'buses' (i.e., those carrying 11 or more persons), the standard requires installation of a lap belt for the driver. The passenger seats on buses are not required to have belts, but lap belts may be installed if desired. For smaller van-type 'buses' (i.e., those carrying 10 or fewer persons) and for passenger cars, the standard requires installation of lap-and-shoulder belts for the driver and right-front passenger positions, and lap belts for all other seating positions.; Safety belt usage requirements are established by the states, not b the Federal government. To date, 14 states have enacted safety belt use laws, and two other states have belt use laws awaiting gubernatorial approval. Those laws generally require belt usage only in passenger cars, we are not aware of any state which requires belt usage in buses. Moreover, as a practical matter, belt use requirements are limited to the equipment actually installed in the vehicle. This agency does urge all motorists to use safety belts wherever they are available, regardless of whether usage is required by state law.; In your letter, you stated your disapproval of state laws that requir the use of safety belts by motorists. You expressed concerns that being restrained by a belt would be unsafe in an accident and that belt usage laws invade your privacy. We appreciate this opportunity to explain our position on those issues relating to belt usage laws, and hope that this discussion will help shed some light on this very important topic.; You seem to believe that the chances of escaping injury in a crash ar greater if safety belts are not worn. Our accident data clearly show that safety belts substantially reduce deaths and serious injuries in a crash. Our traffic records show that vehicle occupants who do not wear their safety belts are nearly twice as likely to suffer serious or fatal injuries than belted occupants. One important reason is that belt usage reduces that likelihood of being thrown outside the vehicle in a crash. We estimate that ejected occupants are 25 times more likely to be killed than those who remain inside the car. Even in the rare cases of vehicle fires or submersion under water, the use of a safety belt improves the chances for survival by keeping the occupants conscious and uninjured so that they may escape quickly.; While we believe the evidence is overwhelming as to the benefits o safety belt usage, we recognize that there are always a few exceptions to the general rule. We are aware that belt usage is not a panacea, some accidents are so severe that injuries or fatalities will result regardless of whether any occupant protection systems are used. However, we believe that the preliminary data from New York, the first state to enact a belt use law, confirms our belief in the lifesaving potential of belt usage. The New York belt usage law went into effect on January 1 of this year and belt usage climbed to roughly 60 percent, and traffic deaths during the first six months of the year declined by 18 percent compared to the same period last year.; We recognize that a safety belt use law requires an action that man people do not take voluntarily. However, all traffic laws involve some restraint on individual behavior. Most are accepted without a second thought: we drive on the right side of the road, obey speed limits and stop at red lights. In many cases, the failure of motorists to obey these laws will have an impact on other motorists as well as themselves. The same is true for failing to wear safety belts, because automobile accidents have many 'victims'--family, friends, employers and taxpayers--all of whom bear some measure of the human and economic cost. During the past decade, 470,000 persons have died on American highways. Each year an estimated 300,000 are injured seriously enough to require hospital treatment. These traffic injuries and deaths have resulted in an annual cost to society of $57 billion resulting from such costs as emergency medical services, long-term medical care and rehabilitation, worker's compensation, welfare payments, and lost tax revenues. We believe that the relatively small intrusion resulting from safety belt use laws is justified by the substantial societal burden of vehicle-related deaths and injury.; Thank you again for sharing your views with us. I hope this informatio is helpful.; Sincerely, Jeffrey R. Miller, Chief Counsel |
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ID: aiam3236OpenMr. Francois Louis, Governmental Affairs, Renault USA, 14250 Plymouth Road, Detroit, MI 48232; Mr. Francois Louis Governmental Affairs Renault USA 14250 Plymouth Road Detroit MI 48232; Dear Mr. Louis: This responds to your letter of March 3, 1980, requesting a interpretation concerning the proper designated seating capacity for the rear seat in the Renault Le Car vehicle. You state that the rear seat of the Le Car has 48.2 inches of hip room, and ask whether the vehicle would qualify as having only two designated seating positions.; I am enclosing a copy of a letter of interpretation the agency recentl issued to Toyota Motor Company regarding the designated seating capacity of the rear seats in several of its models. The rear-seat designs of these Toyota models are very similar to the Le Car, in that the presence of wheel wells results in hip room measurements below 50 inches under the strict measurement technique specified in the definition of 'designated seating position' (SAE J1100a). As was pointed out in that letter, however, if occupants move their hips slightly forward of the wheel wells, which extend only a few inches out into the seat, there is over 50 inches of usable hip room in these vehicles.; Your letter states that the close proximity of the two inboard portion of the rear seat belt assemblies in the Le Car indicates that only two positions are intended by the manufacturer. The agency would give more credence to this factor if the inboard portions of the belt assemblies were on stiff, immovable cables (or similar design). With the current design, a person wishing to sit in the center position can easily move the belts out of the way, so the belts are not real impediments to use of the center position.; In answer to your ultimate question, the agency must conclude that th rear seat in the Le Car vehicle could qualify as having only two designated seating positions since the hip room is below 50 inches according to the technical measurement procedure specified in the standard. However, we think this is an extremely close case since there is over 48 inches of hip room even between the wheel wells and greater than 50 inches of hip room if the measurement is made mid-way the seat cushion. Therefore, we strongly urge Renault to modify its seat design or to add a third set of belts in this vehicle model. As noted in the letter to Toyota, if manufacturers do not voluntarily comply with the clear intent of the definition of 'designated seating position', the agency may find it necessary to modify the measurement technique that is currently specified.; Sincerely, Frank Berndt, Chief Counsel |
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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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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.