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 |
|---|---|
ID: 10947-1Open Giuseppe Di Vito Dear Mr. Di Vito: This responds to your May 22, 1995, letter requesting an interpretation regarding the testing requirements of Federal Motor Vehicle Safety Standard (FMVSS) No. 205, "Glazing Materials." I apologize for the delay in responding. You stated in your letter that you have been requested to manufacture for BMW some type 15A side window security glazing with an internal spall shield coating. Because of the adhesive with which it is applied, this coating cannot pass test number 4 of ANSI Z.26.1-1977 (the boil test). Nevertheless, you urge that test number 5 (the bake test) be used as a substitute for purposes of compliance certification. The boil test and the bake test are not equivalent, and your glazing would have to meet the boil test. Although both tests subject the glazing to the same heat for the same period, the bake test applies the heat using an oven, whereas the boil test applies the heat using boiling water. Section 5 of Z.26 explicitly states that the boil test is to be used for safety glass and that the bake test is only to be used for multiple glazed units. The illustrations that you enclosed with your letter show that your glazing is not a multiple glazed unit. Therefore, it has to meet the boil test to be certified for use on motor vehicles sold in this country. I hope this information is helpful. If you have any further questions or need additional information, please feel free to write Paul Atelsek of my staff at this address or call him at (202) 366-2992. Sincerely, John Womack Acting Chief Counsel ref:205 d:8/4/95
|
1995 |
ID: 10948Open Mr. John C. Golden Dear Mr. Golden: This responds to your request for an interpretation asking if, under NHTSA's requirements, your company may market a lighting device, called a "Lightman," for use on warning triangles. I apologize for the delay in responding. As explained below, the answer to your question is yes. However, since the Federal Highway Administration (FHWA) regulates use of warning triangles carried in commercial vehicles, that agency's regulations could also affect your product. You explain that the Lightman is a battery operated safety strobe device, which is in the shape of an equilateral triangle measuring 3 1/2 inches on each side. You would like to market the Lightman specifically for use on warning triangles, but are concerned about the minimum area requirements of Safety Standard No. 125, Warning Devices. You ask, "Does the mounting of one of these devices...take away minimum reflective area such that it would render the warning triangles illegal or ineffective?" As you note, Standard No. 125 specifies requirements for the configuration of warning devices. Warning devices that are subject to Standard No. 125 must be certified as meeting those configuration requirements. As we understand the Lightman, it will be sold to motorists separately from the Standard No. 125 warning devices. However, we understand that you will market the Lightman as appropriate for use with previously- certified warning devices. There is a provision in our statute that regulates the modifications that motor vehicle manufacturers, dealers, distributors and repair businesses may make to certified vehicles and equipment. (See section 30122 of Title 49 U.S.C. 30101 et seq., copy enclosed.) However, this provision does not regulate the modifications that individuals make to their vehicles or items of equipment, such as warning triangles. Thus, under NHTSA's statute, an individual would not be precluded from placing the light on his or her equilateral triangle. As you note in your letter, the FHWA regulates use of warning devices with regard to commercial trucks, and should be contacted about your question. Responding to your request for a contact in FHWA, we suggest Mr. James Scapellato, Director, FHWA Office of Motor Carrier Research and Standards, at the following address and telephone number: 400 Seventh Street, S.W. Rm. 3107 Washington, DC 20590. Telephone: (202) 366-1790 We will be happy to forward your letter to Mr. Scapellato, if you would like us to do so. I hope this information is helpful. If you have any further questions about our regulations, please feel free to call Dorothy Nakama of my staff at (202) 366- 2992. Sincerely,
John Womack Acting Chief Counsel Enclosure bcc: Mr. Larry Minor Office of Motor Carrier Research & Standards FHWA, Rm. 3107 ref:vsa(a)(2)(A)#125 d:10/16/95
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1995 |
ID: 10949Open Mr. Kenneth Zawlocki Dear Mr. Zawlocki: This responds to your request for an interpretation of Standard No. 218, Motorcycle Helmets. Your questions are addressed below. You first ask whether the Penetration Test (S7.2) tests the outer shell of the helmet, the Impact Attenuation Test (S7.1) tests inner protection materials, and the Retention System Test (S7.3) tests straps that hold the helmet on the head. Each of these tests measures the performance of a motorcycle helmet as a total system, i.e., the tests are conducted on a motorcycle helmet as a whole, rather than on helmet components. Therefore, the tests are not limited to measuring the performance of the components you cite. By way of example, while the shell of the helmet may play a critical role in a helmet's resistance to penetration, the composition and thickness of the liner may also be important. Similarly, while certain components are more important than others in meeting certain criteria, overall design and construction of the helmet will determine whether it meets the impact attenuation and retention requirements. You next ask whether Standard No. 218 specifies the types or amounts of material to be used in manufacturing helmets. Standard No. 218 specifies performance requirements for motorcycle helmets. A manufacturer may use any types or amounts of materials that enable the manufacturer to fully comply with the standard. While Standard No. 218 does not specify that certain materials must be used in manufacturing a helmet, the National Highway Traffic Safety Administration's (NHTSA) experience in over 20 years of helmet testing indicates that helmets meeting Standard No. 218 have common characteristics. The first of these is a dense foam liner that is approximately one inch thick. Helmets with thinner liners or liners composed of a soft compressible foam are not likely to meet the impact attenuation or penetration requirements of the Standard. The weight of the helmet, while not governed by any section of Standard No. 218, is also a good indicator of how it will perform in testing. Although it may be technically possible to build a lightweight helmet that satisfies the performance requirements of Standard No. 218, NHTSA is not aware of any motorcycle helmet weighing less than three pounds that has done so. Finally, you ask whether Standard No. 218 precludes decorating a helmet with any material such as leather or cloth, or with items such as wigs, flowers, decals or hats. The various helmet decorations you describe could affect a motorcycle helmet's compliance with a variety of Standard No. 218's performance requirements. One example is S5.5, Projections. The inside of the shell must be free of protruding rivets or other projections. The presence of any projections within the helmet indicates that it is not a complying helmet. Projecting snaps or other objects are permitted on the outside of the helmet only if they are required for essential accessories such as visors or face shields. Any projection on the outside of a helmet must not protrude more than five millimeters. I note that under 49 U.S.C. '30112(a), "a person may not manufacture for sale, sell, offer for sale, introduce or deliver for introduction in interstate commerce, or import into the United States" a new motorcycle helmet that does not comply with Standard No. 218. Also, dealers and repair businesses may not modify new or used motorcycle helmets in a manner that results in the helmet no longer complying with the standard. Any of these parties must therefore ensure that any contemplated decorations would not affect a helmet's compliance with Standard No. 218. Federal law does not address modifications made by a motorcycle helmet owner to his or her own helmet. However, it is NHTSA's policy to discourage motorcycle helmet users from modifying their helmets. This is because even relatively simple modifications can reduce the safety protection provided by the helmet. S5.6.1(f)(3) of Standard No. 218 requires the following instruction to be placed on helmets: "Make no modifications..." I also note that State laws may address modifications made by motorcycle helmet owners to their own helmets. I hope this information is helpful. If you have further questions, please contact Dorothy Nakama of my staff at (202) 366-2992. Sincerely,
John Womack Acting Chief Counsel ref:218 d:8/29/95
|
1995 |
ID: 1096Open Steven B. Fisher, Esq. Re: Motor Vehicle Safety Standard No. 108 Dear Mr. Fisher: This responds to your letter of July 31, 1995, to Philip R. Recht, formerly Chief Counsel of this agency. You have asked several questions relating to use of the word "practicable" in the lamp location requirements of Federal Motor Vehicle Safety Standard No. 108. Your first question is "with respect to truck, trailer identification lights (red), what is meant exactly by `practicable' as used in SS5.3.1.1 and 5.3.1.4." Your second question is whose responsibility it is to make the determination of practicability. Your final question is whether there is any way for a manufacturer of "a single rear identification light" to know where a trailer manufacturer will install the product on any given trailer. We don't see the word "practicable" in S5.3.1.1. However, S5.3.1.4 does provide that rear clearance lamps need not meet the requirement of Table II that they "be located as close as practicable to the top of the vehicle" when the rear identification lamps are located at the extreme height of the vehicle. Table II specifies location of lighting equipment on the vehicle, and it is therefore the responsibility of the vehicle manufacturer, in certifying that its vehicle complies with all applicable Federal motor vehicle safety standards, to determine what is practicable. As you indicate, a trailer manufacturer may make such a determination "in light of the particular design/configuration of the trailer involved." NHTSA will not contest this determination unless it is clearly erroneous. In short, "practicable" as meant by S5.3.1.4 or any other place where the word occurs, is not a term defined by Standard No. 108, and derives its meaning from specific factual contexts. We note that the Random House Dictionary of the English Language (1967) defines "practicable" as "capable of being done, effected, or put into practice with the available means" (p. 1127). There is no responsibility under Standard No. 108 for the manufacturer of identification lamps to know where its products will be installed on the motor vehicle. Its responsibility under Standard No. 108 is to ensure that any identification lamp that it manufactures for replacement purposes is designed to conform to Standard No. 108's performance specifications and so certified at the time the lamp is shipped from the factory. If you have any further questions you may phone Taylor Vinson of this office (202-366-5263). Sincerely,
John Womack Acting Chief Counsel ref:108 d:8/30/95
|
1995 |
ID: 10975Open Helen A. Rychlewski Dear Ms. Rychlewski: This responds to your letter of June 7, 1995, to the National Highway Traffic Safety Administration (NHTSA), requesting an interpretation of whether a vehicle can be certified as meeting the seat back requirements in S3.2 of Federal Motor Vehicle Safety Standard (FMVSS) No. 201, Occupant Protection in Interior Impact, based on the results of a particular test. The vehicle is equipped with a seat with an inertial latch on the recliner. In order to keep the seat from folding forward during the test procedure specified in FMVSS No. 201, you welded the inertial latch to conduct the test. In past agency interpretation of the safety standards, NHTSA has stated that if (1) there are two or more possible conditions under which a compliance test may be conducted (e.g., whether an inertial lock is engaged or not); (2) the standard does not specify which test condition is to be used, and (3) the language of the standard as a whole and the standard's purpose do not imply a limit that would make one of those conditions inappropriate, there is a presumption that the requirements have to be met under all test conditions. The intent of FMVSS No. 201 is to minimize injuries caused by an occupant striking interior components during a crash. Because inertial latches are intended to lock during a crash, NHTSA believes that testing with the inertial latch engaged most closely indicates the protection offered to an occupant during a crash. Therefore, NHTSA would test a vehicle seat back on a seat with an inertial latch with the latch engaged. The test procedures in NHTSA standards are the procedures NHTSA will use in compliance testing. While manufacturers are not required to test their products using those procedures, they must ensure that the vehicle would comply when tested by NHTSA. NHTSA could weld the latch as you have done, or could engage the inertial latch through other means. If you believe that the test you conducted indicates that the seat back will comply when tested by NHTSA with the latch engaged, such a test may be the basis for your certification. I hope this information has been helpful. If you have any other questions or need additional information, please contact Mary Versailles of my staff at this address or by phone at (202) 366-2992. Sincerely,
John Womack Acting Chief Counsel ref:201 d:8/4/95
|
1995 |
ID: 10992Open Mr. John Renock Dear Mr. Renock: Mr. M. Judson Brown, the project manager for your Transit Authority's compressed natural gas (CNG) bus project, requested that I explain the Federal regulation of CNG containers to you. According to Mr. Brown's letter, the Central New York Regional Transit Authority believes that certain CNG fuel containers are required to be re-inspected and hydrostatically retested every three years. The short explanation is that this agency, the National Highway Traffic Safety Administration (NHTSA), has no authority to regulate the reinspection or retesting of CNG containers used to fuel motor vehicles, after the first consumer purchase. With regard to Mr. Brown's inquiry into the authority of the Research and Special Programs Administration (RSPA) to require reinspection and retesting, we are forwarding your letter to RSPA so that officials of that agency can explain their regulations to you. NHTSA has been authorized by Congress to issue Federal Motor Vehicle Safety Standards (FMVSSs) for new motor vehicles and new items of motor vehicle equipment. The agency has used this authority to issue FMVSS No. 304, Compressed natural gas fuel container integrity, (49 CFR 571.304) which specifies requirements for the integrity of new CNG containers used to fuel motor vehicles. Each new CNG container manufactured on or after March 27, 1995 (the date the standard took effect) must comply with FMVSS No. 304 and be certified as complying with that standard when it is sold. However, after the first consumer purchase of a motor vehicle or an item of motor vehicle equipment, NHTSA's authority is much more limited and does not extend to the reinspection or retesting of motor vehicles or such equipment. I hope you find this information helpful. If you have any other questions, please contact Marvin Shaw at this address or by phone at (202) 366-2992. Sincerely, John Womack Acting Chief Counsel cc: M. Judson Brown ref:304 d:7/18/95
|
1995 |
ID: 10994Open Patrick M. Raher, Esq. Dear Mr. Raher: This responds to your request for an interpretation of the seat position specifications of Standards No. 208, Occupant Crash Protection, and No. 214, Side Impact Protection. These specifications, which are part of the test conditions for the standards' dynamic crash tests, indicate how a vehicle's seats are positioned in those tests. You asked how the specifications apply in the case of power seats which have different maximum seating locations in the forward and rearward position depending on seat height. As discussed below, the seats would be positioned midway between the forwardmost and rearmost positions (with the forwardmost and rearmost positions being determined irrespective of seat height), and at the lowest possible height at that midway position. This appears to correspond to Option 1 in your letter. In your letter, you described a power seat design whose seat position potential is trapezoidal rather than rectangular, due to the mechanism utilized in the power seat operation. In particular, the seat can move further forward in its highest position than in its lowest position, and further rearward in its lowest position than in its highest position. You also indicated that a lowering of the seat from a higher position has the effect of moving the seat backward. The seat position specifications of Standards No. 208 (S8.1.2) and No. 214 (S6.3) read as follows: Adjustable seats are in the adjustment position midway between the forwardmost and rearmost positions, and if separately adjustable in a vertical direction, are at the lowest position. If an adjustment position does not exist midway between the forwardmost and rearmost positions, the closest adjustment position to the rear of the midpoint is used. This provision sets forth two conditions concerning how an adjustable seat is positioned in a crash test. The first condition, for the longitudinal position of the seat, is for the seat to be in the adjustment position midway between the forwardmost and rearmost positions. The terms "forwardmost" and "rearmost" are not qualified by height, so the absolute forwardmost and rearmost positions would be used, irrespective of seat height at those positions. The second condition, for the vertical position of a seat which is separately adjustable in a vertical direction, is for the seat to be in the lowest position. We interpret this to refer to the lowest vertical position that can be attained at the longitudinal position described above. Therefore, in positioning a seat for a crash test, we would not change the longitudinal position of the seat merely because the mechanism was designed so that lowering the seat from a higher position had the effect of moving the seat backward. Instead, we would find the lowest vertical position that could be attained at the specified longitudinal position. I hope this information is helpful. If you have any further questions, please feel free to call Edward Glancy of my staff at 366-2992. Sincerely,
John Womack Acting Chief Counsel ref:208 d:8/31/95
|
1995 |
ID: 10999Open Mr. Tim Phillips Dear Mr. Phillips: This responds to your letter of June 21, 1995, in which you asked us to update your information on new tire sizing codes used in the DOT identification of tires. Please be advised that this agency no longer specifies tire size codes. 49 Code of Federal Regulations (CFR) '574.5, Tire identification requirements (copy enclosed), requires tire manufacturers to label on one sidewall of each tire it produces a tire identification number (TIN), and specifies that the TIN will be composed of four groupings, the second of which "shall be used to identify the tire size." The size requirement in the TIN was first promulgated as '574.4 on November 10, 1970 (35 FR 17257). At that time, NHTSA (then the National Highway Safety Bureau) specified in Table 1 of the regulation the codes to be used to designate the various tire sizes. In the following two years, the agency amended Table 1 numerous times to add new codes to represent additional tire sizes. On November 8, 1972 NHTSA published a final rule rescinding Table 1 and the agency-specified tire codes (37 FR 23727). The agency explained that because of the many new tire sizes being introduced, available new codes had become exhausted and it was necessary to change the system to one permitting greater flexibility. Accordingly, the agency amended the regulation to permit manufacturers to assign their own two-digit code to represent tire size and to permit retreaders to use either a self-assigned matrix code or a self-assigned tire size code. The November 8, 1972 amendment also required each new tire manufacturer and retreader to maintain a record of each symbol used and provide that information to NHTSA upon written request. Those requirements remain in effect (49 CFR '574.5(b)). In summary, 49 CFR '574.5 no longer specifies tire size codes for use as the second grouping of symbols in TINs. Rather, the regulation permits manufacturers and retreaders to use their own tire size codes in that grouping of the TIN. I hope this information is helpful to you. Should you have any further questions or need additional information, please feel free to contact Walter Myers of my staff at this address or at (202) 366-2992. Sincerely,
John Womack Acting Chief Counsel Enclosure
ref:574 d:8/4/95
|
1995 |
ID: 11-000612 M.Edie (Part 523)OpenMark D. Edie Office of the General Counsel Ford Motor Company 1350 I Street N.W., Suite 450 Washington, D.C. 20005 Re: Request for Interpretation of 49 CFR 523.2 AND 523.5(b)(2) Dear Mr. Edie: This is a response to your letter on January 21, 2011, in which you requested an interpretation of 49 CFR 523.2 and 523.5(b)(2) as they would apply to the classification of a motor vehicle with components affixed to its undercarriage. The specific components described in your letter are tire aero deflectors, which are attached in front of the tires in order to reduce aerodynamic drag and thereby improve fuel economy. Your letter states that in order to perform as needed, some of the components may be between 20 and 15 centimeters from their lowest point to the ground. The components are made of flexible plastic and capable of bending without breaking and returning to their original position after encountering solid objects up to 20 centimeters in height at typical off-road speeds. You requested our confirmation that this type of component would be excluded from the running clearance measurement in 49 CFR 523.5(b)(2), and thus allow vehicles equipped with these components to be classified as light trucks for CAFE compliance purposes, provided that they meet all other required criteria for that classification. This letter provides the agencys opinion based on the information provided. By way of background, the National Highway Traffic Safety Administration (NHTSA) does not endorse or approve the classification of any motor vehicle. This is the responsibility of the vehicle manufacturer, who must also ensure that the vehicle complies with all applicable regulatory requirements. In order to comply with CAFE requirements, the manufacturer must classify its vehicles according to the definitions in 49 CFR Part 523, as promulgated under 49 U.S.C. 32901(a)(17)-(19). Improper classification can result in NHTSA determining that a manufacturers CAFE compliance obligations for its passenger car and light truck fleets are different from those assumed by the manufacturer, and create difficulties in meeting the standards. NHTSAs regulations at 49 CFR 523.5 provide two basic ways in which a vehicle can be classified as a light truck for CAFE purposes: 523.5(a) covers vehicles that the agency considers functional light trucks, that are not passenger cars because they were not manufactured primarily for transporting up to ten individuals; and 523.5(b) covers vehicles which are expressly excluded from the passenger car category due to their capability for off-highway operation.[1] Your question focuses on 523.5(b), which states that a vehicle must either: (1)(i) [Have] 4-wheel drive; or (ii) [Be] rated at more than 6,000 pounds gross vehicle weight; and (2) [Have] at least four of the following characteristics calculated when the automobile is at curb weight, on a level surface, with the front wheels parallel to the automobile's longitudinal centerline, and the tires inflated to the manufacturer's recommended pressure (i) Approach angle of not less than 28 degrees. (ii) Breakover angle of not less than 14 degrees. (iii) Departure angle of not less than 20 degrees. (iv) Running clearance of not less than 20 centimeters. (v) Front and rear axle clearances of not less than 18 centimeters each. Running clearance is defined in 49 CFR 523.2 as the distance from the surface on which an automobile is standing to the lowest point on the automobile, excluding unsprung weight. We have previously interpreted 49 CFR 523.5(b) to mean that it does not require a vehicle to meet four of the five criteria [of 523.5(b)(2)] at all ride heights; however, a vehicle must meet four out of the five criteria in at least one ride height.[2] In the situation presented in that prior interpretation, the vehicle was equipped with a driver-controllable variable ride height suspension system. In some positions, the vehicle would have had a running clearance of less than 20 centimeters, but the agency determined that it was appropriate, for CAFE classification purposes, to measure the vehicles running clearance with its adjustable suspension placed in the position(s) intended for off-road operation under real-world conditions.[3] |
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ID: 11-000697_Trooper_Kile_205Open
Trooper James S. Kile 266 Periwinkle Lane New Market, Virginia 22844
Dear Trooper Kile:
This responds to your letter asking about the applicability of Federal Motor Vehicle Safety Standard (FMVSS) No. 205, Glazing Materials, to shade bands on windshields of passenger vehicles. You ask 1) whether Federal law permits any type of obstruction or tinting above the AS-1 line on the windshield; and 2) in the absence of an AS-1 line, is any tinting or other type of obstruction permitted near the top of the windshield. FMVSS No. 205 does not contain restrictions on tinting or opaque obstructions in the shade band area. Furthermore, the area of the windshield with a light transmittance of less than 70% must be marked by the AS-1 line.
By way of background, the National Highway Traffic Safety Administration (NHTSA) is authorized by the National Traffic and Motor Vehicle Safety Act (49 U.S.C. Chapter 301) to issue Federal motor vehicle safety standards for new motor vehicles and motor vehicle equipment. Pursuant to that authority, the agency has established FMVSS No. 205, which specifies performance requirements for various types of glazing (called items), and specifies the locations in vehicles where each item of glazing may be used. The standard also incorporates by reference industry standards, the American National Standard for Safety Glazing Materials for Glazing Motor Vehicles and Motor Vehicle Equipment Operating on Land Highways Safety Standard (ANSI Z26.1-1996) and SAE J100, Passenger Car Glazing Shade Bands.
ANSI Z26.1-1996 requires that all glazing materials used in areas of the vehicle requisite for driving visibility have a light transmittance level of not less than 70%. FMVSS No. 205 allows a shade ban area or opaque area used to mount the rearview mirror near the top of the windshield. These areas are permitted to have a light transmittance level of less than 70%. Section 7 of ANSI Z26.1-1996 requires that glazing materials requisite for driving visibility with areas having a light transmittance level of less than 70% be permanently marked with the AS-1 line with an arrow pointed to the area that has a light transmittance level greater than 70%.
FMVSS No. 205 requires that shade bands conform to either SAE J100 or paragraph S5.3.2 which mandate the lower boundary of the shade band. Neither SAE J100 nor paragraph S5.3.2 specify a luminous transmittance level for the shade ban area. Thus, FMVSS No. 205 does not prohibit any type of tinting or opaque obstruction in the shade band area provided that the windshield will be able to meet all other performance requirements specified in ANSI Z26.1-1996. Thus, FMVSS No. 205 does not prohibit any tinting or opaque obstructions above the AS-1 line assuming that the AS-1 line is in a location specified by SAE J100 or paragraph S5.3.2.
On vehicles without a shade ban the AS-1 line must mark the lowest point of the break area, the opaque area at the top of the windshield and in the center where the rearview mirror is mounted. If no AS-1 line is present on the windshield, the entire windshield must have at least a 70% light transmittance level. A windshield with no AS-1 line would still be permitted to have shade band or other tinting at the top of the windshield provided that the light transmittance of the shade band or tinting was not less than 70%.
If you have any further questions, you may refer them to Thomas Healy of this office at 202-366-7161.
Sincerely,
O. Kevin Vincent Chief Counsel
5/10/2011 |
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.