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: aiam1676OpenMemorandum to Interpretation of Certification Regulations (49 CFR Part 567), From Acting Chief Counsel, Subject: Files; Memorandum to Interpretation of Certification Regulations (49 CFR Part 567) From Acting Chief Counsel Subject: Files; In a letter recently mailed by this agency in a current enforcemen action, the following interpretation of 49 CFR Part 567 appeared:; '567.5(g) - The information on the label is not presented in th specified order or form. Your use of a vehicle model designation within the body of the label is unacceptable. However, it is permissible to list your vehicle model after the last statement, which is the vehicle type.'; Richard B. Dyson |
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ID: aiam0964OpenMr. W. G. Milby, Project Engineer, Blue Bird Body Company, Fort Valley, GA 31030; Mr. W. G. Milby Project Engineer Blue Bird Body Company Fort Valley GA 31030; Dear Mr. Milby: In our letter to you of December 7, 1972, regarding Standard 217, Bu Window Retention and Release, we incorrectly stated in the answer to question 5 that an amendment currently being prepared would clarify Figures 1 and 2 to indicate the location of the bus wall in relation to the seat. We do not feel such a clarification is necessary for the purposes of the standard. The intent of those figures is to establish a space envelope containing certain reach distances with respect to the seat, and the location of the wall is therefore not relevant.; Sincerely, Richard B. Dyson, Assistant Chief Counsel |
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ID: aiam2959OpenMr. Frank Tedesco, President, Lifetime Foam Products, Inc. 3001 Cullerton Drive, Franklin Park, IL 60131; Mr. Frank Tedesco President Lifetime Foam Products Inc. 3001 Cullerton Drive Franklin Park IL 60131; Dear Mr. Tedesco: This is in response to your letter of February 8, 1979, requestin confirmation of your understanding of an October 7, 1976, letter of interpretation by our office concerning Safety Standard No. 207, *Seating Systems*. You are correct in your assumption that the standard applies only to completed vehicles and not to vehicle seats as individual equipment.; Sincerely, Frank Berndt, Acting Chief Counsel |
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ID: aiam4474OpenRusty Mitchell A-Z Bus Sales, Inc. P.O. Box 9389 5555 W. Mission Blvd. Ontario, CA 91762; Rusty Mitchell A-Z Bus Sales Inc. P.O. Box 9389 5555 W. Mission Blvd. Ontario CA 91762; "Dear Mr. Mitchell: This is a response to your letter of November 11 1987, in which you asked for information on the 'application of seat belts in school buses.' I am pleased to have this opportunity to explain our regulations to you. The National Highway Traffic Safety Administration (NHTSA) is responsible for developing safety standards applicable to all new motor vehicles, including school buses. In 1977, we issued a set of motor vehicle safety standards regulating various aspects of school bus performance. Among those standards is Standard 222, School Bus Passenger Seating and Crash Protection. Standard 222 requires large school buses (those with a gross vehicle weight rating over 10,000 pounds) to afford passenger crash protection by means of 'compartmentalization.' Compartmentalization requires large school buses to incorporate certain protective elements into the vehicles' interior construction, thereby reducing the risk of injury to school bus passengers without the need for safety belts. These elements include high seats with heavily padded backs and improved seat spacing and performance. Our regulations require a safety belt for the school bus driver because the driver's position is not compartmentalized. Further, because small school buses (10,000 pounds or less GVWR) experience greater force levels in a crash, Standard 222 requires the added protection of safety belts at each passenger position in a small school bus. School buses continue to have one of the lowest fatality rates for any class of motor vehicle. Large school buses are among the safest motor vehicles because of their size and weight (which generally reduce an occupant's exposure to injury-threatening crash forces), the drivers' training and experience, and the extra care other motorists usually take when they are near a school bus. For these reasons, our regulations do not require safety belts for passengers in large school buses. I enclose a copy of a June 1985 NHTSA publication titled 'Safety Belts in School Buses,' which discusses many of the issues relative to this subject. You also asked whether there is an order form listing available data for safety belts in school buses. This agency does not publish 'order forms' for any data. For further information on this subject, you may wish to contact individual school bus manufacturers to ask for data about safety belts in their buses. I hope you find this information helpful. Sincerely, Erika Z. Jones Chief Counsel Enclosure"; |
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ID: aiam1226OpenMr. C. J. Goode, British Leyland Uk Limited, Meteor Works, Lode Lane, Solihull, Warwickshire B92 8NW; Mr. C. J. Goode British Leyland Uk Limited Meteor Works Lode Lane Solihull Warwickshire B92 8NW; Dear Mr. Goode: In your letter of July 5, 1973, you express two concerns about th treatment of multipurpose passenger vehicles under the Motor Vehicle Information and Cost Savings Act.; Your first concern is that the standards to be issued under the ac will apply to all passenger motor vehicles, and will include multipurpose passenger vehicles unless the agency expressly exempts them. As we stated in the notice of proposed rulemaking on the new bumper standard, we are proposing to exempt multipurpose passenger vehicles from the initial standard. The continuance of this exemption depends on a variety of considerations, and we would appreciate the benefit of your views on the subject.; Your second concern is that the definition of 'multipurpose passenge vehicle' in the safety standards (49 CFR 571.3(b)) differs from the definition of the same term in the Cost Savings Act. Although the definitions are fundamentally similar, the safety standards definition limits the MPV category to vehicles designed to carry 10 persons or less, while the Cost Savings Act definition includes somewhat larger vehicles, up to a capacity of 12 persons. We do not foresee any problems as a result of this difference, but if problems arise, it would be possible through rulemaking to restrict the applicability of a cost savings standard to MPV's having a capacity of 10 persons.; Sincerely, James B. Gregory, Administrator |
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ID: aiam4024OpenMr. Robert C. Blunt, Papy, Poole, Weissenborn & Papy, 201 Alhambra Circle, Suite 502, Coral Gables, FL 33134; Mr. Robert C. Blunt Papy Poole Weissenborn & Papy 201 Alhambra Circle Suite 502 Coral Gables FL 33134; Dear Mr. Blunt: This responds to your two letters to former Chief Counsel Jeffre Miller in which you sought information concerning our Uniform Tire Quality Grading Standards (UTQGS).; In your first letter, you enclosed a copy of a newspaper article tha appeared in the Miami Herald. That article stated that a 'Federal study' rated projected mileage for 134 different radial tires, and ranked the 'best' and 'worst' tires. You asked for a copy of this study, along with the standards used by the agency to grade treadwear, traction, and temperature-resistance for tires. Your second letter indicates you subsequently received a copy of our UTQGS (49 CFR S575.104), which sets forth the procedures the tire manufacturers use to grade their tires. As discussed below, the 'Federal study' referenced in the newspaper article is merely information taken from tire manufacturers' UTQGS submissions to the agency.; As set forth in the UTQGS, this agency requires the tire manufacturer to assign grades to each of their tire designs. NHTSA then makes available to the public the grade assignments reported to it by the tire manufacturers. Hence, the tests to which the article referred were conducted entirely by the individual tire manufacturers, not by the Federal government.; Neither the tire manufacturers nor the agency made, or could make, an total tire mileage projections from the reported treadwear grades. If one were to project total mileage from the treadwear grade, one could say only that a certain tire might get x miles if driven over the same roads at the same speeds on the same vehicles with the same careful maintenance performed daily on those vehicles. A projection of a tire's treadlife which did not include all of these caveats would be misleading.; Finally, the agency does not categorize particular tires as the best o the worst based solely on the treadwear grades assigned by the manufacturers. Such an approach ignores the importance of the traction and temperature resistance grades, both of which have far greater significance from a safety standpoint than does the treadwear grade. Because of the many variables involved in selecting the most appropriate tire, this agency cannot state that any particular tire is the best for most drivers.; In your second letter, you stated that you had received a 198 publication entitled 'Tire Grading System Information,' and requested a copy of the 1983 and 1984 updates of that publication. The agency did not update that publication during those years. Instead, all interested consumers have been provided with a complete listing of all grades which have been reported to the agency, together with an explanatory sheet telling how to use those grades. I have enclosed a copy of those grades for your information.; For your information, NHTSA suspended treadwear grading requirement under the UTQGS, effective February 8, 1983. This action was announced after the agency found high levels of variability in treadwear test results and in the grade assignment practices of the various tire manufacturers. This variability resulted in a substantial likelihood that treadwear information being provided to the public under this program would be misleading, i.e., that the assigned treadwear grades could, in many instances, incorrectly rank the actual treadwear performance of different tires.; On April 24, 1984, the United States Court of Appeals for the Distric of Columbia Circuit vacated the agency's suspension of the treadwear grading requirements in *Public Citizen v. Steed*, 733 F.2d 93. Accordingly, the agency published a final rule reimplementing the treadwear grading requirements on December 19, 1984 (49 FR 49293, copy enclosed). Hence, if you were seeking treadwear grades for 1983 and 1984, none were assigned during those years.; If you have any further questions or need more information on thi subject, please contact Steve Kratzke of my staff at this address or by telephone at (202) 426-2992.; Sincerely, Erika Z. Jones, Chief Counsel |
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ID: aiam2780OpenR. L. Ratz, P.E., Product Safety Engineering, Grumman Flxible Corporation, 970 Pittsburgh Drive, Delaware, OH 43015; R. L. Ratz P.E. Product Safety Engineering Grumman Flxible Corporation 970 Pittsburgh Drive Delaware OH 43015; Dear Mr. Ratz: This responds to your recent letter asking whether Safety Standard No 209, *Seat Belt Assemblies*, and Safety Standard No. 210, *Seat Belt Anchorages*, would be applicable to a Type I seat belt assembly used as a securement device for wheelchairs in an urban transit bus.; Safety Standard No. 209 is an equipment standard that is applicable t any seat belt manufactured for use on passenger cars, multipurpose passenger vehicles, trucks or buses. Therefore, the seat belt in question would have to comply with the performance requirements of that standard.; Safety Standard No. 210, however, only specifies requirements for sea belt anchorages at the driver's position on buses. Since the assembly you are concerned with would be at a passenger seating position in the bus, it would not have to comply with the anchorage requirements of Standard No. 210.; Sincerely, Joseph J. Levin, Jr., Chief Counsel |
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ID: aiam3892OpenThe Honorable Dave Durenberger, United States Senate, Washington, DC 20510; The Honorable Dave Durenberger United States Senate Washington DC 20510; Dear Senator Durenberger: Thank you for your recent letter on behalf of your constituent, Mr Pius J. Lacher, the Superintendent of Schools in Mora, Minnesota. Your letter has been referred to my office for reply.; As I understand Mr. Lacher's letter, the Mora public schools would lik to use 12 and 15 passenger vans to transport children to and from extra- curricular activities. Mr. Lacher believes that he is restricted by our Federal regulations to using only large, 72-passenger buses for this purposes. He urges a change in the regulations.; I appreciate this opportunity to clarify our regulations. In thi letter, I would like to explain how our regulations might affect Mora's choice of buses. Before I begin, let me explain that our regulations define a 'bus' as a motor vehicle designed to carry 10 or more passengers. Our regulations require manufacturers and dealers to certify that new buses comply with all applicable motor vehicle safety standards, including our school bus safety standards, when these vehicles are sold to schools.; Our agency has two sets of regulations, issued under different Acts o Congress, that could affect Mora's choice of buses. The first of these, the motor vehicle safety standards issued by our agency under the National Traffic and Motor Vehicle Safety Act of 1966 (Public Law 89-563, 15 U.S.C. 1381-1426) apply to the manufacture and sale of new motor vehicles. In a 1974 amendment to the Act, Congress expressly directed us to issue standards on specific aspects of school bus safety, including emergency exits, seating systems, windows and windshields, and bus structure. The standards we issued became effective April 1, 1977, and apply to each school bus manufactured on or after that date. If Mora plans to buy a *new* bus for use as an activity bus, the manufacturer and dealer must certify that the bus complies with the motor vehicle safety standards applicable to school buses. New conventional 12 or 15 passenger vans that are not manufactured to comply with these standards could not be sold for use as school buses.; The Vehicle Safety Act does not prohibit Mora from using vehicles tha carry more than 10 persons. There might, however, be impediments under Minnesota State law. We administer a set of guidelines for state highway safety programs under the authority of the Highway Safety Act (Public Law 89-564, 23 U.S.C. 401-408). These guidelines, called Highway Safety Programs Standards, cover a wide range of subjects, including school buses. Individual states have chosen to adopt some or all of the guidelines as their own policies governing their highway safety program. Highway Safety Program Standard No. 17 (HSPS 17), specifies that a bus used to transport 16 or less students must either be identified with the words 'School Bus' and comply with the standard's requirements for color, mirrors and signal lamps, or be devoid of all of these characteristics. As it happens, however, a bus sold for use as a school bus is required by the Vehicle Safety Act to have warning lights and mirrors (as well as many other safety features). Because it must have this equipment, a 12 or 15 passenger bus in a State whose law fully incorporates HSPS 17 would have to be painted and signed as a school bus. For a state that has adopted this standard as its own policy, these specifications apply to activity buses as well as to the buses used for daily transportation.; I want to stress that HSPS 17 will affect Mora only if Minnesota ha adopted it and if Minnesota accepts our view that the specifications apply to activity buses. If Minnesota chooses to exempt activity buses from being painted, signed, and equipped as school buses, we might disagree with the wisdom of its decision but we would not insist on compliance with HSPS 17 to the extent of taking action against the State. Congress has given us discretion under the Highway Safety Act not to insist that a State comply with every requirement of the highway safety standards. While we have stressed the importance of a strong pupil transportation program, consistent with HSPS 17, we have not insisted that the States comply with every feature of the standard.; Having said this, however, I would like to restate the importance tha our agency attaches to the use of safe buses to transport children. It remains the agency's position that a yellow school bus meeting the motor vehicle safety standards is the safest means of transportation for school children. In the years since buses began to be manufactured with these safety features, there has been a marked improvement in school bus safety. Mora should consider these safety features when the school district decides to buy their school vehicles. Please let me know if you have any further questions.; Sincerely, Frank Berndt, Chief Counsel |
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ID: aiam0617OpenMr. Jack Gardner, President, Artcraft - Milwaukee, Inc., 117 West Pittsburgh Avenue, Milwaukee, WI, 53204; Mr. Jack Gardner President Artcraft - Milwaukee Inc. 117 West Pittsburgh Avenue Milwaukee WI 53204; Dear Mr. Gardner: This is in reply to your letter of February 25, 1972, concerning th application of Motor Vehicle Safety Standard No. 302, 'Flammability of Interior Materials,' to replacement bus seat covers.; Standard No. 302 does not apply to aftermarket or replacemen materials. It applies only to new vehicles manufactured after September 1, 1972, as of the time of their manufacture, and does not apply to replacement materials used in those vehicles.; We trust this clarifies the situation for you. Yours truly, Richard B. Dyson, Assistant Chief Counsel |
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ID: aiam3938OpenMr. Gerald A. Lakas, Custom Window Tinting Services, 5016-A 46th Avenue, Hyattsville, MD 20781; Mr. Gerald A. Lakas Custom Window Tinting Services 5016-A 46th Avenue Hyattsville MD 20781; Dear Mr. Lakas: Thank you for your letter concerning our regulations that affec tinting businesses, such as yours. I hope that the following discussion will clarify our regulations and answer the questions you raised.; Please note that in all the correspondence the agency has had with you your attorney, and others concerning your business, we have never stated that it is illegal to add all tinting to the glazing of a motor vehicle. We have stated, however, that it is illegal to add some types and levels of tinting. Let me explain further the effect our regulations on tinting.; *Federal Law* The National Traffic and Motor Vehicle Safety Act authorizes our agenc to issue Federal Motor Vehicle Safety Standards that apply to new motor vehicles and items of motor vehicle equipment. In 1967, the agency issued Federal Motor Vehicle Safety Standard No. 205, *Glazing Materials*, which sets performance requirements for glazing materials used in new motor vehicles and glazing materials sold as items of replacement equipment. (A copy of that standard and the American National Standards Institute's code incorporated by reference in our standard has been previously provided to you.); The performance requirements of the standard include ones regulatin the light transmittance and abrasion resistance of glazing. A manufacturer of new vehicles must certify that the glazing in windows requisite for driving visibility, whether clear or tinted, conforms with the light transmittance and other requirements of the standard. Likewise, if a dealer or other person places tinting film on glazing in a new vehicle prior to the sale of the vehicle, that person must certify that the glazing continues to be in compliance with the requirements of Standard No. 205. Thus, for example, the light transmittance through the combination of tinting film and the glazing must be at least 70 percent in the case of glazing used in windows requisite for driving visibility. Similarly, the combination must also meet the abrasion resistance and other requirements of the standard.; In 1974, Congress amended the National Traffic and Motor Vehicle Safet Act to address the problems of persons tampering with safety equipment installed on a motor vehicle after its first sale. The 1974 amendments added section 108(a)(2)(A) to the Act. That section provides, in part that:; >>>No manufacturer, distributor, dealer, or motor vehicle repai business shall knowingly render inoperative, in whole or 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 . . . .<<<; Thus no manufacturer, distributor, dealer, or motor vehicle repai business may add tinting to the glazing materials of a motor vehicle, if that tinting would render inoperative the glazing's compliance with Standard No. 205. Again, section 108(a)(2)(A) does not prohibit tinting, it merely limits the use of tinting. The agency has consistently attempted to explain our interpretation of section 108(a)(2)(A) in letters to vehicle, glazing, and tinting manufacturers, state governments, and individual tinting shops. You indicated that we need to do a better job of conveying our interpretation to all affected persons. We will look at ways to accomplish that goal.; Section 108(a)(2)(A) does not establish any limitations on a individual vehicle owner's ability to alter his or her own vehicle. Under Federal law, individual vehicle owners can themselves install any tinting they want on their vehicles, regardless of whether that tinting would render inoperative the compliance of the vehicle's glazing with the performance requirements of Standard No. 205. The agency, of course, urges individual owners not to install dark tinting on their vehicles.; *State Law* Although the agency does not have the authority to regulate the action of individual vehicle owners, States do have such authority. The agency is aware that a number of States have adopted laws which address the tinting of motor vehicles. Let me emphasize that State laws which are inconsistent with these Federal requirements are preempted. Any State law or regulation which would permit any person to install tinting material on a new vehicle in violation of Standard No. 205 is preempted under section 103(d) of the Vehicle Safety Act. for example, a State law which specifies a transmittance level less than 70 percent for windows requisite for driving visibility in new vehicles would be preempted. The adoption or retention of such a law would have no effect on the illegality of that installation under Federal law. Further, any State law or regulation that would permit manufacturers, distributors, dealers or motor vehicle repair businesses to install tinting materials on a vehicle after its first sale in violation of section 108(a)(2)(A) of the Vehicle Safety Act is also preempted.; *Requirements for Different Vehicles* You asked for an explanation of why there is a difference between th visibility requirements set for passenger cars and other motor vehicles. The agency has generally applied more stringent safety requirements for passenger cars, the most prevalent type of vehicle on the road, and has subsequently applied the same or similar requirements to other vehicle types.; In the case of the glazing requirements, the agency has considered al the windows in a passenger car requisite for driving visibility. The agency has applied different requirements to other vehicles such as vans, because of traditional differences in their construction and use. Many vans are constructed without any windows to the rear of the driver. In addition, the space behind the driver in vans is frequently used to haul objects which prevent an interior view to the rear of the vehicle. Because of this situation, the agency has required trucks, buses and van-type vehicles to have dual outside mirrors to ensure that the driver will have a view to the rear of the vehicle.; *VESC Guidelines* You also asked about the guidelines adopted by the Vehicle Equipmen Safety Commission (VESC). In 1958, Congress authorized the creation of VESC for the purpose of encouraging State cooperation in the establishment and carrying out of traffic safety programs. VESC, however, had no authority to adopt regulatory standards that would directly affect individuals, manufacturers, dealers, distributors, or motor vehicle repair businesses. Although VESC could recommend guidelines, those guidelines would have to be adopted by the States to have the force of law. VESC ceased operations in January 1984. In 1980, VESC adopted a guideline, designated as VESC-20, on the tinting of glazing on used vehicles. Several of the provisions in VESC-20 conflict with the requirements of Standard No. 205. As discussed above, the adoption of VESC-20 by a State would govern the use of tinting by an individual vehicle owner. However, that State law would not affect the use of tinting by manufacturers, distributors, dealers, and motor vehicle repair businesses, whose conduct would still be affected by our regulations.; You asked about Maryland's adoption of a regulation based, in part, o VESC-20. Since VESC- 20 is merely a guideline, Maryland is free to choose the portions of VESC-20 it wishes to adopt, but those portions conflicting with Standard No. 205 are subject to Federal preemption.; *AAMVA Approval* You asked about the effect of a 'notice of equipment compliance' issue to tinting manufacturers by the American Association of Motor Vehicle Administrators (AAMVA), which apparently is a certification by the AAMVA that the material complies with VESC-20. Our regulations do not require a manufacturer of tinting materials to obtain a notice of equipment compliance from AAMVA. Individual States may have adopted regulations which require tinting manufacturers to obtain such notices.; Whether a manufacturer has an AAMVA notice or its tinting material ha been approved by a State has no effect on our regulations. As explained above, if a manufacturer, dealer, distributor, or motor vehicle repair business install tinting film which would render inoperative the glazing materials compliance with Standard No. 205, there would be a violation of section 108(a)(2)(A) of the Vehicle Safety Act.; If you have any further questions, please let me know. Sincerely, Jeffrey R. Miller, Chief Counsel |
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.