Standard Reference Test Tire

Published date05 August 2021
Citation86 FR 42762
Record Number2021-15361
SectionProposed rules
CourtNational Highway Traffic Safety Administration
Federal Register, Volume 86 Issue 148 (Thursday, August 5, 2021)
[Federal Register Volume 86, Number 148 (Thursday, August 5, 2021)]
                [Proposed Rules]
                [Pages 42762-42775]
                From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
                [FR Doc No: 2021-15361]
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                DEPARTMENT OF TRANSPORTATION
                National Highway Traffic Safety Administration
                49 CFR Parts 571 and 575
                [Docket No. NHTSA-2020-0067]
                RIN 2127-AL92
                Standard Reference Test Tire
                AGENCY: National Highway Traffic Safety Administration (NHTSA),
                Department of Transportation (DOT).
                [[Page 42763]]
                ACTION: Notice of proposed rulemaking (NPRM).
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                SUMMARY: This document proposes amendments to several Federal motor
                vehicle safety standards and consumer information regulations to update
                the standard reference test tire (SRTT) used therein. The SRTT is used
                in those standards and regulations as a baseline tire to rate tire
                treadwear, define snow tires based on traction performance, and
                evaluate pavement surface friction. This proposed rule is necessary
                because the only manufacturer of the currently referenced SRTT ceased
                production of the tire. Referencing a new SRTT ensures the availability
                of a test tire for testing purposes.
                DATES: Submit comments on or before September 7, 2021.
                ADDRESSES: You may submit comments electronically to the docket
                identified in the heading of this document by visiting the following
                website:
                 Federal eRulemaking Portal: Go to http://www.regulations.gov. Follow the online instructions for submitting
                comments.
                Alternatively, you can file comments using the following methods:
                 Mail: Docket Management Facility: U.S. Department of
                Transportation, 1200 New Jersey Avenue SE, West Building Ground Floor,
                Room W12-140, Washington, DC 20590-0001.
                 Hand Delivery or Courier: West Building Ground Floor, Room
                W12-140, 1200 New Jersey Avenue SE, between 9 a.m. and 5 p.m. ET,
                Monday through Friday, except Federal holidays. To be sure someone is
                there to help you, please call (202) 366-9826 before coming.
                 Fax: (202) 493-2251.
                 Regardless of how you submit your comments, you should mention the
                docket number identified in the heading of this document.
                 Instructions: For detailed instructions on submitting comments and
                additional information on the rulemaking process, see the Public
                Participation heading of the Supplementary Information section of this
                document. Note that all comments received will be posted without change
                to http://www.regulations.gov, including any personal information
                provided. Please see the Privacy Act heading below.
                 Privacy Act: In accordance with 5 U.S.C. 553(c), DOT solicits
                comments from the public to better inform its rulemaking process. DOT
                posts these comments, without edit, to www.regulations.gov, as
                described in the system of records notice, DOT/ALL-14 FDMS, accessible
                through www.dot.gov/privacy. In order to facilitate comment tracking
                and response, we encourage commenters to provide their name, or the
                name of their organization; however, submission of names is completely
                optional. Whether or not commenters identify themselves, all timely
                comments will be fully considered. If you wish to provide comments
                containing proprietary or confidential information, please contact the
                agency for alternate submission instructions.
                 Docket: For access to the docket to read background documents or
                comments received, go to http://www.regulations.gov. Follow the online
                instructions for accessing the dockets.
                FOR FURTHER INFORMATION CONTACT: You may contact Hisham Mohamed, Office
                of Crash Avoidance Standards, by telephone at (202) 366-0307 or David
                Jasinski, Office of the Chief Counsel, by telephone at (202) 366-2992.
                The mailing address of both of these officials is: National Highway
                Traffic Safety Administration, 1200 New Jersey Avenue SE, Washington,
                DC 20590.
                SUPPLEMENTARY INFORMATION:
                I. Background
                 This rulemaking addresses the standard reference test tire (SRTT)
                manufactured according to specifications set forth in an ASTM
                International standard, E1136, ``Standard Specification for P195/75R14
                Radial Standard Reference Test Tire'' (14-inch SRTT). The 14-inch SRTT
                is a size P195/75R14 all-season steel-belted radial tire. The
                dimensions, weight, materials, and other physical properties of the
                tire are specified in E1136. The tire is not intended for general use,
                but as the name indicates, is used for testing.
                 The 14-inch SRTT was first introduced in the 1980s. The 14-inch
                SRTT was manufactured by one company, Michelin North America, Inc
                (Michelin) and was sold under its Uniroyal brand. NHTSA uses the 14-
                inch SRTT to evaluate tire treadwear performance \1\ by comparing a
                candidate tire's performance to the performance of the SRTT in a
                particular performance test. NHTSA also uses the 14-inch SRTT to
                evaluate test surface friction \2\ for safety standards relating to
                braking because the narrow specifications for the tire (size, component
                materials, etc.) ensure consistent, repeatable performance.
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                 \1\ 49 CFR 575.104.
                 \2\ 49 CFR 571.105, 571.121, 571.122, 571.126, 571.135, 571.136,
                571.139, 571.500.
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                 NHTSA first incorporated the 14-inch SRTT into the Federal Motor
                Vehicle Safety Standards (FMVSSs) in a 1995 rule adopting FMVSS No.
                135, the light vehicle braking standard.\3\ Previously, NHTSA had used
                skid number to define the road test surface in the light vehicle
                braking test. Testing a surface to determine skid number involved using
                a locked wheel. However, modern anti-lock brake systems (ABS) are
                designed to achieve maximum friction prior to a wheel becoming locked
                and the tire skidding. An anti-lock brake system prevents wheel lockup
                by modulating a vehicle's brakes at a point just before the wheels
                would lock up. Consequently, in the 1995 final rule, NHTSA adopted ASTM
                method E1337, ``Standard Test Method for Determining Longitudinal Peak
                Braking Coefficient (PBC) of Paved Surfaces Using Standard Reference
                Test Tire,'' as the means for evaluating test surfaces.\4\ ASTM E1337
                measures the peak braking force prior to wheel lockup, which
                corresponds to the behavior of an anti-lock brake system. ASTM E1337
                specifies the use of the E1136 SRTT in order to ensure that variability
                in tire size, material, or construction does not affect the evaluation
                of test surfaces.
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                 \3\ 60 FR 6411, 6415-17 (Feb. 2, 1995).
                 \4\ Another reason for adopting the peak braking force related
                to the variability associated with determining skid number. That
                matter was discussed in more detail in NHTSA's earlier proposals to
                require heavy vehicles to be equipped with anti-lock brake systems.
                See 49 FR 20465 (May 14, 1984); 49 FR 28962 (July 17, 1984).
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                 Over time, the evaluation of a test surface using the ASTM E1337
                test method and the E1136 SRTT was incorporated into the heavy vehicle
                braking standards (FMVSS Nos. 105 and 121), the light and heavy vehicle
                electronic stability control standards (FMVSS Nos. 126 and 136), the
                motorcycle braking standard (FMVSS No. 122), and the low-speed vehicle
                standard (FMVSS No. 500).\5\
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                 \5\ ASTM E1337 is also incorporated by reference into 49 CFR
                575.106, which are the provisions related to a new tire consumer
                information program. However, the test procedures in 49 CFR 575.106
                are not currently used pending publication of a proposed and final
                rule establishing the remaining aspects of the consumer information
                program. See 75 FR 15893 (Mar. 30, 2010). Therefore, this proposal
                does not address 49 CFR 575.106. In a proposal implementing the
                remaining aspects of that tire consumer information program, NHTSA
                would address the issues discussed in this proposal.
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                 The use of the 14-inch SRTT is also incorporated into the
                definition of a ``snow tire'' in FMVSS No. 139. Specifically, a ``snow
                tire'' is defined as a tire that attains a traction index greater than
                or equal to 110 compared to the 14-inch SRTT when using the ASTM F1805
                snow traction test. The ASTM F1805 snow traction test measures the
                driving traction of tires while traveling in a
                [[Page 42764]]
                straight line on snow- and ice-covered surfaces. Tires that meet the
                definition of ``snow tires'' are subject to less stringent performance
                test requirements compared to other tires subject to FMVSS No. 139.\6\
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                 \6\ See 71 FR 877, 880 (Jan. 6, 2006).
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                 The SRTT is also used as part of the Uniform Tire Quality Grading
                Standards (UTQGS), an information program to assist consumers in making
                informed decisions when purchasing tires. The UTQGS apply to passenger
                car tires and require motor vehicle and tire manufacturers and tire
                brand name owners to provide consumers with information about their
                tires' relative performance regarding treadwear, traction, and
                temperature resistance.
                 The 14-inch SRTT is used as part of the determination of a tire's
                UTQG treadwear rating. As part of the UTQG test procedures, treadwear
                is measured by running the tires being tested (called candidate tires)
                in convoys over a 400-mile course of public roads near San Angelo,
                Texas. The performance of tires over this course can change daily due
                to variability in the road surface, temperature, humidity, and
                precipitation. To compensate for changes in condition of the test
                course, candidate tires are tested concurrently with course monitoring
                tires (CMTs).
                 NHTSA has used the 14-inch SRTT as the exclusive CMT since 1991.
                CMTs must be not more than one year old at the time of commencement of
                the test and must be used within two months from being removed from
                storage in order to prevent variability resulting from aging of the
                CMT. The performance of the CMT is used to determine the base course
                wear rate (BCWR) by running four-vehicle convoys equipped with 16 CMTs
                for 6,400 miles over the test course four times per year. \7\ The wear
                rate of the CMT over the prior four quarterly CMT test runs are
                averaged to calculate the BCWR, which is published in Docket No. NHTSA-
                2001-9395. The BCWR is used to determine a course severity adjustment
                factor, which is applied to the comparison between the candidate tires
                and CMTs to determine a tire's rating.
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                 \7\ See 65 FR 33481 (May 24, 2000).
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                II. Proposal To Replace 14-Inch SRTT With 16-Inch SRTT
                 This proposal would amend NHTSA's safety standards and regulations
                to no longer reference the 14-inch SRTT. Because of technological
                advancements in the development of tires and the general trend of
                increasing rim diameter sizes since the 1980s, the size and materials
                of the 14-inch SRTT are no longer representative of modern tires sold
                in the U.S. Further, Michelin has ceased production of the 14-inch SRTT
                because it has become difficult for Michelin to obtain the materials
                necessary to manufacture the SRTT.\8\ Thus, NHTSA seeks to reference a
                different standard reference test tire in the agency's safety standards
                and regulations and to transition seamlessly to the new tire in the
                agency's compliance and consumer information test programs.
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                 \8\ See ``Discontinued Tire Will Lead to ASTM Standard Changes''
                (July 30, 2015), available at https://www.astm.org/cms/drupal-7.51/newsroom/discontinued-tire-will-lead-astm-standard-changes (last
                accessed April 13, 2021).
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                 ASTM International has developed an updated specification for an
                SRTT designated F2493 (16-inch SRTT). The 16-inch SRTT is size P225/
                60R16. The 16-inch SRTT is considered to be more representative of
                current tires because of its larger size and new material and design
                features that lead to traction that is more typical of modern passenger
                car tires.\9\ To the best of NHTSA's knowledge, the 16-inch SRTT is
                manufactured only by Michelin and sold under its Uniroyal brand.
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                 \9\ See ``New ASTM Specification Presents Requirements for
                Standard Reference Test Tire'' (April 1, 2007), available at https://www.astm.org/cms/drupal-7.51/newsroom/new-astm-specification-presents-requirements-standard-reference-test-tire (last accessed
                April 13, 2021).
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                 To reference an SRTT that is more representative of tires on the
                road today, and in consideration of Michelin's decision to cease
                production of the 14-inch SRTT, NHTSA has determined that replacing the
                14-inch SRTT in its regulations is warranted. The only suitable
                replacement for the 14-inch SRTT that has been suggested to NHTSA is
                the 16-inch SRTT. However, because the 16-inch SRTT is a larger size
                and uses more modern design and materials, it is likely that the 16-
                inch SRTT will not perform identically to the 14-inch SRTT. Therefore,
                NHTSA has been cooperating with Transport Canada, Natural Resources
                Canada, representatives of ASTM International committees F09 on tires
                and E17 on vehicle-pavement systems, the U.S. Tire Manufacturers
                Association (including Michelin, currently the sole manufacturer of
                SRTTs), and the Rubber Association of Canada to conduct testing to
                determine the consequences of replacing the 14-inch SRTT with the 16-
                inch SRTT. The results of the testing by these entities, in addition to
                NHTSA's own testing, have substantially contributed to this proposal to
                replace the 14-inch SRTT with the 16-inch SRTT.\10\
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                 \10\ See Docket No. NHTSA-2020-0067.
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                A. Proposed FMVSS Amendments
                1. Surface Friction Measurement
                 As discussed above, other than for defining a ``snow tire,'' NHTSA
                uses the SRTT in the FMVSSs to define the surface coefficient of
                friction for the test surface for braking and electronic stability
                control (ESC) standards. The friction of the test surface is measured
                by the peak braking force prior to wheel lockup, which is referred to
                as a peak friction coefficient (PFC) or peak braking coefficient (PBC).
                For the purpose of this preamble, NHTSA uses the term peak friction
                coefficient or PFC, but the terms are used interchangeably in the
                FMVSS.
                 In the FMVSS, the peak friction coefficient of a surface is
                determined using the 1990 version of ASTM E1337 test method. The ASTM
                E1337 test method involves mounting the SRTT to a test trailer,
                bringing the trailer to a test speed of 40 mph (64 km/h), and applying
                the brake to produce the maximum braking force prior to wheel lockup.
                 When NHTSA was informed that production of the 14-inch SRTT was to
                be discontinued, NHTSA evaluated the 16-inch SRTT to determine whether
                it would be a suitable replacement. NHTSA carefully considered the
                effect of the 16-inch SRTT on the determination of PFC. NHTSA was
                concerned that the use of the 16-inch SRTT without further changes to
                the FMVSSs would increase the stringency of the braking and ESC FMVSSs.
                The reason for this was that the different materials used in the 16-
                inch SRTT and the increased size of the tire would result in the 16-
                inch SRTT having better traction performance than the 14-inch SRTT. If
                the 16-inch SRTT has improved traction performance relative to the 14-
                inch SRTT, then the same surface would have a higher PFC when tested
                with the 16-inch SRTT. Alternatively stated, obtaining an identical PFC
                value using the 16-inch SRTT would require a road surface with lower
                friction. Testing braking systems using stopping distance on road
                surfaces with lower friction would require improved braking performance
                to stop in the same distance, which is not an outcome intended by this
                rulemaking. Consequently, NHTSA sought a conversion factor to evaluate
                PFC of a test surface using the 16-inch SRTT without altering the
                severity of any braking or ESC FMVSSs.
                [[Page 42765]]
                 Initial testing confirmed the assumption that using the 16-inch
                SRTT resulted in a test surface having a higher PFC than when evaluated
                using the 14-inch SRTT. Transportation Research Center, Inc. (TRC)
                conducted initial testing in support of the ASTM committee evaluating
                this issue (the E17.21 committee).\11\ Testing was conducted on 15
                different surfaces of varying friction. The evaluation of a dry test
                surface (e.g., 0.9 PFC using the 14-inch SRTT) using the 16-inch SRTT
                resulted in a PFC over 15 percent higher than the PFC derived using the
                14-inch SRTT. However, testing on a low friction surface (0.5 PFC using
                the 14-inch SRTT) showed that the PFC derived using the 16-inch SRTT
                and the 14-inch SRTT was similar.
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                 \11\ See docket No. NHTSA-2020-0067.
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                 Because the difference in performance between the 16-inch SRTT and
                the 14-inch SRTT was not consistent for all levels of surface friction,
                something more than a simple multiplier is necessary to correlate
                performance between the two tires. ASTM International has developed
                such a formula. That formula is included in the 2019 update to ASTM
                E1337, which NHTSA is proposing to incorporate by reference into the
                FMVSSs, in place of the 1990 version of E1337 currently referenced.
                NHTSA has used the formula in the 2019 version of E1337 to derive PFC
                value for all of the FMVSSs. Those values are listed in the table
                below.
                 Each value derived using the formula was rounded to the hundredths
                position, rounding up if necessary. This ensures that the updated FMVSS
                test surface PFC specification will be no more stringent as a result of
                this proposed amendment than it is now, consistent with NHTSA's intent
                in this rulemaking.
                ------------------------------------------------------------------------
                 PFC value using PFC value using
                 FMVSS section 14-inch SRTT 16-inch SRTT
                ------------------------------------------------------------------------
                FMVSS No. 105 S6.9.2(a) (high 0.9 1.02
                 friction testing)..................
                FMVSS No. 105 S6.9.2(b) (low 0.5 0.55
                 friction testing)..................
                FMVSS No. 121 S5.3.1.1, S5.7.1, 0.9 1.02
                 S6.1.7 (high friction testing) \12\
                FMVSS No. 121 S5.3.6.1, S6.1.7 (low 0.5 0.55
                 friction testing)..................
                FMVSS No. 122 S6.1.1.1 (high 0.9 1.02
                 friction testing)..................
                FMVSS No. 122 S6.1.1.2 (low friction =0.8 >=0.90
                FMVSS No. 126 S6.2.2................ 0.9 1.02
                FMVSS No. 135 S6.2.1, S7.4.3, 0.9 1.02
                 S7.5.2, S7.6.2, S7.7.3, S7.8.2,
                 S7.9.2, S7.10.3, S7.11.3...........
                FMVSS No. 136....................... 0.9 1.02
                FMVSS No. 500 \13\.................. 0.9 1.02
                ------------------------------------------------------------------------
                 NHTSA commissioned confirmatory testing using the 16-inch SRTT to
                verify that the PFC values discussed above are equivalent to the PFC
                values in the FMVSSs derived using the 14-inch SRTT. NHTSA has
                contracted with TRC to conduct this testing on five different test
                surfaces (wet ceramic, wet jennite, wet asphalt, dry asphalt, and dry
                broomed concrete). These test surfaces range from high to low PFC
                values. For each test surface, 10 of each of the 14-inch SRTT and the
                16-inch SRTT were each tested 3 times with 10 stops per test, for a
                total of 300 tests for each size SRTT on each test surface. A final
                report summarizing the results has been placed in the docket identified
                at the beginning of this NPRM.
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                 \12\ NHTSA is also proposing to revise Tables I, II, and IIA in
                FMVSS No. 121 to eliminate the redundant references to PFC values in
                those tables. In place of PFC values, NHTSA is proposing to include
                in Table I (Stopping Sequence) references to the sections in which
                the various procedures are set forth, which is a more helpful
                reference.
                 \13\ Although FMVSS No. 500 specifies a PFC value for the test
                surface, the test surface is only used to verify the vehicle's
                maximum speed.
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                2. Snow Tire Definition
                 Presently, for a manufacturer to designate a tire as a ``snow
                tire,'' the tire must attain a traction index equal to or greater than
                110 compared to the 14-inch SRTT when tested using the snow traction
                test in the 2000 version of ASTM F1805. The ASTM F09 committee on tires
                commissioned a study to determine the feasibility of replacing the 14-
                inch SRTT with the 16-inch SRTT in the determination of whether a tire
                meets the definition of ``snow tire.'' This study was funded by the
                United States Tire Manufacturers Association (USTMA).
                 The study consisted of testing of traction during the winter test
                seasons of 2016, 2017, and 2018 to develop a method to correlate
                results of tests conducted using the 16-inch SRTT with those conducted
                using the 14-inch SRTT. ASTM International has published a technical
                report documenting this work.\14\ ASTM International determined that a
                correlation factor of 0.9876 was appropriate, meaning that a tire that
                attained a rating of 110 when tested using the 14-inch SRTT correlated
                to a rating of 111.4 or 111.5 when tested using the 16-inch SRTT,
                depending on the number of significant digits considered. Recent
                guidance issued by the USTMA, a trade association consisting of
                companies that manufacture tires in the United States, recommends a
                minimum traction index of 112 using the 16-inch SRTT.\15\ Accordingly,
                NHTSA is proposing to amend the definition of ``snow tire'' in FMVSS
                No. 139 to specify that a snow tire is a tire that attains a traction
                index of 112 when tested using the updated F1895 test method using the
                16-inch SRTT. This proposal is consistent with the guidance issued by
                USTMA, which NHTSA believes reflects a consensus within the tire
                industry on the appropriate traction index for use in determining what
                qualifies as a ``snow tire.'' NHTSA seeks comment on this proposal.
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                 \14\ Available at https://www.astm.org/COMMIT/2019_04_10_E1136%20to%20F2493%20transition%20for%20ASTMF1805.pdf
                (last accessed April 13, 2021).
                 \15\ See https://www.ustires.org/sites/default/files/USTMA_TISB_37_0.pdf (last accessed April 13, 2021).
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                 Furthermore, after reviewing this information from the USTMA, NHTSA
                determined that additional clarification was necessary to the
                definition of a ``snow tire'' in FMVSS No. 139. The latest (2020)
                version of ASTM F1805 defines the standard test procedure for measuring
                traction on ``snow'' and ``ice'' surfaces. However, there are multiple
                surface types in both the ``snow'' and ``ice'' categories. They include
                soft pack (new) snow, medium pack snow, medium hard pack snow, hard
                pack snow, ice--wet, and ice--dry.\16\ The definition of ``snow tire''
                in FMVSS No.
                [[Page 42766]]
                139 does not specify the surface type specified within ASTM F1805 for
                testing.
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                 \16\ The surface types are defined in the text of ASTM F1805.
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                 NHTSA interprets that the ``medium pack snow'' condition was
                intended for use by manufacturers for marketing tires as ``snow
                tires.'' NHTSA seeks comment on whether this assumption is correct. It
                is the surface type specified for severe snow tires in UNECE Regulation
                No. 117 for determining when use of the Alpine or Three-Peak Mountain
                Snowflake marking that indicates that a tire meets the requirements for
                use in severe snow conditions. Based upon the research on the SRTT, the
                2020 revision of ASTM F1805 contains a revised tractive coefficient
                range for ``medium pack snow'' using the 14-inch SRTT from 0.25-0.41 to
                0.25-0.38 and adds a tractive coefficient range for ``medium pack
                snow'' using the 16-inch SRTT of 0.23-0.38.
                 Based on the research by ASTM International and USTMA's recent
                guidance, NHTSA is proposing to update the definition of a ``snow
                tire'': (1) To replace the reference to the 14-inch SRTT with the 16-
                inch SRTT and to change the minimum traction index in order to meet the
                definition of a ``snow tire'' from 110 to 112 using this tire; (2) to
                specify that this traction index is obtained when tested on the
                ``medium pack snow'' surface, and (3) to update the incorporation by
                reference of ASTM F1805 from the 2000 version to the 2020 version,
                which is the latest version. ASTM F1805-20 incorporates the research
                discussed above. NHTSA is not aware of other research on equivalent
                performance of the 14-inch SRTT and 16-inch SRTT on snow-covered
                surfaces other than the testing by ASTM International.
                B. Proposed UTQGS Amendments
                 In anticipation of Michelin's decision to cease production of the
                14-inch SRTT, NHTSA began including testing of the 16-inch SRTT as part
                of its BCWR determination. Since the second quarter of 2016, NHTSA has
                been duplicating BCWR testing using both the 14-inch SRTT and the 16-
                inch SRTT. NHTSA has shared some data from this testing with its
                testing partners (named at the end of Section I of this preamble) in
                order to develop options that could be implemented once production of
                the 14-inch SRTT has ended. Four options have been considered:
                 1. Use the research data to develop a correlation formula between
                the 14-inch SRTT and the 16-inch SRTT. While this would allow future
                testing and rating to be based on either SRTT, it was likely to be the
                most resource-intensive to develop and validate a formula.
                 2. Establish an effective date for the 16-inch SRTT and begin
                publishing the quarterly BCWR after that date using four quarters of
                data using that tire. After two quarters of testing it was apparent
                that this was likely to result in a shift in the BCWR. However, large
                shifts in BCWR have occurred in the past, such as when repaving was
                done on portions of the route.
                 3. Allow a transition period in which NHTSA would publish BCWR
                rates for both SRTTs, allowing manufacturers to choose when to shift
                within that period.
                 4. Establish an effective date to begin quarterly testing with the
                16-inch SRTT, but continue to calculate the BCWR rate using the prior
                quarterly testing results used to calculate prior BCWR rates. The first
                quarter with official testing using the 16-inch SRTT CMT would result
                in a BCWR rate calculated from the average of those results and the
                results of the previous three quarters testing using the 14-inch SRTT
                CMT, the second quarter would average two quarters with the 16-inch
                SRTT CMT and 2 quarters with the 14-inch SRTT CMT, and so on.
                 In 2017, Michelin informed NHTSA that the test results from the
                first two quarters of testing were within the normal variability seen
                for BCWR.\17\ Michelin believed that NHTSA could develop an entirely
                new formula for determining BCWR, but believed that such a formula may
                not be able to be developed prior to the end of production of 14-inch
                SRTT. Instead, Michelin recommended adding a new conversion factor to
                the existing formula derived from the ratio of the BCWR from the 14-
                inch SRTT CMT to the BCWR of the 16-inch SRTT CMT measured over a
                specific number of quarters of testing. Michelin recommended that this
                factor be based on at least six quarters of testing, which was all the
                testing that was available at the time of Michelin's recommendation.
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                 \17\ Michelin presentation; UTQG Wear Change from 14'' TO 16''
                SRTT First Two Test Quarters. See docket No. NHTSA-2020-0067.
                ---------------------------------------------------------------------------
                 NHTSA now has 14 consecutive quarters of testing data. Table 1
                summarizes the quarterly BCWR values determined by NHTSA since the
                first quarter of 2017. As shown in Table 1, NHTSA has determined BCWR
                reference values for the 16-inch SRTT. Table 1 also shows BCWR rates
                for the 16-inch SRTT beginning in Q2 2017 after four quarters of BCWR
                values were obtained. Table 1 also shows a conversion factor based on
                the ratio of the BCWR using the 14-inch SRTT to the BCWR using the 16-
                inch SRTT measured over all available quarters of testing.
                 Table 1--Quarterly BCWR Data Since April 2016
                --------------------------------------------------------------------------------------------------------------------------------------------------------
                 Derived
                 14-inch SRTT BCWR 16-inch SRTT BCWR Quarterly Theoretical 16- conversion factor
                 data data published BCWR inch SRTT BCWR based on prior
                 rate rate six quarters
                --------------------------------------------------------------------------------------------------------------------------------------------------------
                January-March 2017....................................... 8.090 5.349 9.059 ................. .................
                April-June 2017.......................................... 7.556 5.952 8.573 ................. .................
                July-September 2017...................................... 9.640 6.189 8.692 ................. .................
                October-December 2017.................................... 8.932 6.578 8.555 6.017 .................
                January-March 2018....................................... 7.481 5.731 8.402 6.113 .................
                April-June 2018.......................................... 8.253 6.074 8.577 6.143 1.392
                July-September 2018...................................... 9.648 6.467 8.579 6.213 1.393
                October-December 2018.................................... 8.867 6.602 8.562 6.219 1.403
                January-March 2019....................................... 6.555 5.999 8.331 6.286 1.328
                April-June 2019.......................................... 8.242 5.506 8.328 6.144 1.348
                July-September 2019...................................... 7.243 5.656 7.727 5.941 1.344
                October-December 2019.................................... 7.237 6.206 7.319 5.842 1.312
                January-March 2020....................................... 7.695 5.259 7.604 5.657 1.301
                April-June 2020.......................................... 6.719 5.616 7.224 5.684 1.276
                [[Page 42767]]
                
                July-September 2020...................................... 6.983 6.856 7.159 5.984 1.257
                October-December 2020.................................... 8.122 6.886 7.380 6.154 1.206
                January-March 2021....................................... 7.228 4.687 7.263 6.011 1.239
                --------------------------------------------------------------------------------------------------------------------------------------------------------
                 The conversion factor listed in the last column of Table 1 is
                determined by dividing the average of six quarters of BCWR testing with
                the 14-inch SRTT by the average of the same six quarters of BCWR with
                the 16-inch SRTT. The conversion factor is similar for all quarters
                currently available. NHTSA requests comments on how the new conversion
                factor should be selected from among the available quarters of data.
                For example, NHTSA could use the last six (or some other number) of
                quarters of data, or all data available to determine the conversion
                factor. NHTSA requests comments on which of these possible conversion
                factors NHTSA could use and why.
                 For this NPRM, NHTSA is basing the adjustment on the average of all
                17 consecutive quarters of available data. The average BCWR wear rate
                using the 14-inch SRTT is 7.911. The average BCWR wear rate using the
                16-inch SRTT is 5.942. Dividing 7.911 by 5.977 results in a conversion
                factor of 1.324. Based upon this new conversion factor, the new formula
                for the treadwear grade, assuming the decision was to use the most
                recent quarter's conversion factor, would be: \18\
                ---------------------------------------------------------------------------
                 \18\ The first equation definition P is set forth in 49 CFR
                57.104(e)(2)(ix)(F).
                ---------------------------------------------------------------------------
                BILLING CODE 4910-59-P
                [GRAPHIC] [TIFF OMITTED] TP05AU21.038
                BILLING CODE 4910-59-C
                 NHTSA does not believe the calculation of projected mileage as used
                in this formula also requires adjustment, as the calculation takes into
                consideration the actual measurement of the CMT used during the test of
                the candidate tire being evaluated.
                 NHTSA is also proposing to modify language in the treadwear test
                procedure in Sec. 575.104 to reference the total distance and schedule
                of events in terms of circuits completed rather than mileage. This
                proposed change is intended to allow testing to be more flexible in the
                vent of route changes or other unforeseen circumstances. With the added
                flexibility of these changes, NHTSA believes that it is preferable to
                use the actual mileage of the completed circuit in the calculation of
                the wear rate rather than the estimated 400 miles per circuit. NHTSA
                believes that this would ensure that the wear rate reflects the actual
                mileage covered if the completed 16 circuits is not exactly 6,400
                miles. NHTSA seeks comment on these proposed changes and any potential
                effects they may have on the testing process or data integrity.
                 NHTSA also seeks comment on the specification in the note to Sec.
                575.104(e)(2)(ix)(C) that the CMT must
                [[Page 42768]]
                be no more than one year old at the commencement of testing and that it
                must be used within two months after removal from storage. NHTSA lacks
                facilities to store tires in a climate-controlled environment at its
                testing facility in San Angelo, Texas. Therefore, because of the time
                limitations on the use of the CMT in the BCWR testing, NHTSA only
                purchases CMTs on a quarterly basis depending on funding availability
                and conducts BCWR testing as soon as feasible after receiving a
                shipment of CMTs. Lack of funding sometimes requires NHTSA to delay CMT
                purchases, and sometimes when NHTSA purchases CMTs, supplies may be
                limited, meaning that NHTSA is required to wait weeks or months before
                receiving CMTs for testing. To increase NHTSA's flexibility in
                purchasing and testing CMTs, NHTSA is considering lengthening the
                amount of time tires may be removed from storage to four months, so
                that NHTSA can purchase CMTs in advance and store them in its San
                Angelo facility. NHTSA also requests comment on whether the word
                ``storage'' is sufficiently well defined and, if not, how NHTSA could
                define ``storage'' more clearly to ensure tires are stored in such a
                way that would minimize testing variability without providing
                inflexible limitations on NHTSA's use of the SRTT. NHTSA requests
                comment on this proposed change.
                C. Summary
                 Based on the foregoing, NHTSA has tentatively concluded that the
                best course of action in response to Michelin's determination to cease
                production of the 14-inch SRTT is to replace the 14-inch SRTT with the
                16-inch SRTT for all uses in NHTSA's standards and regulations. Because
                the 16-inch SRTT is a different size and made of different materials,
                changes are necessary to the FMVSS and tire regulations to ensure that
                the use of the 16-inch SRTT to evaluate test surface friction does not
                alter the stringency of the standards or the treadwear ratings of tires
                in the UTQGS treadwear testing program. NHTSA tentatively believes that
                this proposal accomplishes those goals. NHTSA requests comment on that
                determination, the merits of these goals, and whether the proposed
                amendments would accomplish those goals. NHTSA also seeks comment on
                the use and storage requirements for the CMT tires used in the BCWR
                calculation.
                III. Effective Date
                 For the changes to the UTQGS, NHTSA expects to make these changes
                effective at the next BCWR determination at least 30 days after the
                date of publication of a final rule. NHTSA does not believe any further
                lead time is necessary for the following reasons. First, because NHTSA
                is using a conversion factor to keep the rating scale used with the 14-
                inch SRTT and 16-inch SRTT identical, ratings of a particular line of
                tires should not be affected by this proposed rule. Second, tire lines
                rated prior to the effective date of the changes proposed in this rule
                would not be required to be rerated. Third, limited availability of the
                14-inch SRTT could make it difficult for NHTSA to continue to obtain
                14-inch SRTTs in its BCWR determinations. NHTSA is currently restricted
                by its regulations to using SRTTs that were manufactured within one
                year prior to the commencement of testing and two months after removal
                from storage in order to prevent variability in results due to tire
                aging. This provision prevents NHTSA from stockpiling 14-inch SRTTs.
                 For FMVSS changes, NHTSA is proposing a lead time of six months.
                This will give NHTSA's compliance test facilities sufficient time to
                obtain and validate test surfaces using the 16-inch SRTT. Although
                NHTSA has determined an equivalent level of surface friction when
                evaluating PBC with the 16-inch SRTT in place of the 14-inch SRTT,
                NHTSA anticipates requiring test facilities conducting NHTSA's
                compliance tests to revalidate test surfaces using the 16-inch SRTT, to
                ensure that testing is being done in accordance with the procedures in
                the FMVSS. A six-month lead time is consistent with the requirements of
                49 U.S.C. 30111(d) that standards be effective between 180 days and 1
                year after they are prescribed. However, potential unavailability of
                the 14-inch SRTT may constitute good cause for NHTSA to impose a
                shorter lead time in a final rule resulting from this proposal.
                 NHTSA does not believe that manufacturers require more than six
                months of lead time. Because NHTSA intends the proposed peak braking
                coefficient specifications in the FMVSS using the 16-inch SRTT to be an
                equivalent level of friction to existing peak braking coefficients
                using the 14-inch SRTT, NHTSA does not intend to affect the FMVSS
                compliance of any vehicle and does not believe this proposal would do
                so.
                 NHTSA requests comments on the proposed lead time for changes to
                the UTQGS and FMVSSs.
                IV. Public Participation
                How do I prepare and submit comments?
                 To ensure that your comments are correctly filed in the Docket,
                please include the docket number of this document in your comments.
                 Your comments must not be more than 15 pages long (49 CFR 553.21).
                NHTSA established this limit to encourage you to write your primary
                comments in a concise fashion. However, you may attach necessary
                additional documents to your comments. There is no limit on the length
                of the attachments.
                 Please submit your comments electronically to the docket following
                the steps outlined under ADDRESSES. You may also submit two copies of
                your comments, including the attachments, by mail to Docket Management
                at the beginning of this document, under ADDRESSES.
                How can I be sure that my comments were received?
                 If you wish to be notified upon receipt of your mailed comments,
                enclose a self-addressed, stamped postcard in the envelope containing
                your comments. Upon receiving your comments, Docket Management will
                return the postcard by mail.
                How do I submit confidential business information?
                 If you wish to submit any information under a claim of
                confidentiality, you should submit the following to the NHTSA Office of
                Chief Counsel, 1200 New Jersey Avenue SE, Washington, DC 20590: (1) A
                complete copy of the submission; (2) a redacted copy of the submission
                with the confidential information removed; and (3) either a second
                complete copy or those portions of the submission containing the
                material for which confidential treatment is claimed and any additional
                information that you deem important to the Chief Counsel's
                consideration of your confidentiality claim. A request for confidential
                treatment that complies with 49 CFR part 512 must accompany the
                complete submission provided to the Chief Counsel. For further
                information, submitters who plan to request confidential treatment for
                any portion of their submissions are advised to review 49 CFR part 512,
                particularly those sections relating to document submission
                requirements. Failure to adhere to the requirements of part 512 may
                result in the release of confidential information to the public docket.
                In addition, you should submit two copies from which you have deleted
                the
                [[Page 42769]]
                claimed confidential business information, to Docket Management at the
                address given at the beginning of this document under ADDRESSES. To
                facilitate social distancing during COVID-19, NHTSA is temporarily
                accepting confidential business information electronically. Please see
                https://www.nhtsa.gov/coronavirus/submission-confidential-business-information for details.
                Will the agency consider late comments?
                 NHTSA will consider all comments received before the close of
                business on the comment closing date indicated at the beginning of this
                document under DATES. In accordance with DOT policies, to the extent
                possible, NHTSA will also consider comments received after the
                specified comment closing date. If NHTSA receives a comment too late to
                consider in developing the proposed rule, NHTSA will consider that
                comment as an informal suggestion for future rulemaking action.
                How can I read the comments submitted by other people?
                 You may read the comments received on the internet. To read the
                comments on the internet, go to http://www.regulations.gov and follow
                the on-line instructions provided.
                 You may download the comments. The comments are imaged documents,
                in either TIFF or PDF format. Please note that even after the comment
                closing date, NHTSA will continue to file relevant information in the
                Docket as it becomes available. Further, some people may submit late
                comments. Accordingly, NHTSA recommends that you periodically search
                the Docket for new material.
                 You may also see the comments at the address and times given near
                the beginning of this document under ADDRESSES.
                V. Regulatory Analyses
                A. Executive Order 12866, Executive Order 13563, and DOT Rulemaking
                Procedures
                 NHTSA has considered the impact of this rulemaking action under
                Executive Order 12866, Executive Order 13563, and the Department of
                Transportation's administrative rulemaking procedures. This rulemaking
                is not considered significant and was not reviewed by the Office of
                Management and Budget under E.O. 12866, ``Regulatory Planning and
                Review.''
                 This proposal updates the standard reference test tire used as a
                baseline tire for consumer information testing, in the determination of
                what is a snow tire, and to evaluate testing surface friction for
                evaluating braking and electronic stability control performance. This
                proposal will not have a direct effect on safety because the changes
                proposed in this rule are designed to maintain the present level of
                stringency of NHTSA's braking and electronic stability control FMVSSs.
                However, if the 14-inch SRTT is discontinued without a replacement,
                NHTSA would be unable to verify test surface friction coefficient prior
                to compliance testing for braking and electronic stability control
                system FMVSSs. Thus, this rulemaking indirectly affects safety by
                ensuring that NHTSA would be able to perform compliance tests of those
                FMVSSs. Also, if this proposal were not adopted, it is expected that
                the 14-inch SRTT would soon no longer be available for purchase,
                rendering it impossible for NHTSA to continue maintaining the BCWR for
                treadwear testing. This unavailability of an SRTT would lead to tire
                manufacturers being unable to rate their tires for treadwear under the
                UTQGS and mold those ratings onto the side of the tire as required by
                49 CFR part 575.
                 This proposed rule is expected to result in additional costs to
                NHTSA because the 16-inch SRTT has a retail price that is $35 per tire
                more than the 14-inch SRTT ($335 vs. $300).\19\ NHTSA purchases 64
                SRTTs for its own use annually in determining BCWR. Therefore, based on
                the cost difference of $35 per tire, NHTSA expects that, if adopted,
                this proposal would result in $2,240 additional annual costs to the
                government. However, NHTSA has been using the 14-inch SRTT and 16-inch
                SRTT side-by-side since 2016 for its quarterly BCWR determination in
                anticipation of this rulemaking and NHTSA plans to continue to do so
                until this proposal is finalized. After this proposal is finalized,
                NHTSA does not expect to continue purchasing 14-inch SRTTs. Therefore,
                when compared to years since 2016, NHTSA would likely purchase fewer
                SRTTs in subsequent years after this proposal is finalized.
                ---------------------------------------------------------------------------
                 \19\ Data on the price of the SRTT was obtained from
                instructions on how to purchase SRTTs from Michelin. See https://www.astm.org/COMMIT/2011%2011%2008%20E1136%20F2493%20SRTT%20Purchase%20Procedure.pdf.
                (last accessed April 13, 2021).
                ---------------------------------------------------------------------------
                 As to potential costs to the public, based upon information
                provided to NHTSA by Michelin from 2017 and 2018, annual U.S. sales of
                14-inch SRTTs is fewer than 2,000 units. Assuming that U.S. sales of
                16-inch SRTTs is comparable to sales of 14-inch SRTTs, the annual cost
                of this proposal would be less than $70,000. However, NHTSA does not
                know how many sales are a consequence of the SRTT being used as part of
                NHTSA's compliance test procedures, versus those sold for other
                purposes (e.g., SRTTs sold to assess the performance of tires to some
                other country's regulations or to voluntary industry standards). Any
                SRTT sales that are not related to compliance with NHTSA's regulations
                would not be affected by this proposal and the existence of such sales
                would mean this rule would be less costly than the maximum estimate of
                $70,000 per year. Moreover, NHTSA does not have any direct knowledge of
                whether regulated entities have been conducting side-by-side testing
                using both the 14-inch SRTT and 16-inch SRTTs like NHTSA has and
                whether side-by-side testing has artificially increased sales in 2017
                and 2018.
                 NHTSA requests comments on the benefits and costs of this NPRM.
                B. Regulatory Flexibility Act
                 Pursuant to the Regulatory Flexibility Act (5 U.S.C. 601 et seq.,
                as amended by the Small Business Regulatory Enforcement Fairness Act
                (SBREFA) of 1996), whenever an agency is required to publish a notice
                of rulemaking for any proposed or final rule, it must prepare and make
                available for public comment a regulatory flexibility analysis that
                describes the effect of the rule on small entities (i.e., small
                businesses, small organizations, and small governmental jurisdictions).
                The Small Business Administration's regulations at 13 CFR part 121
                define a small business, in part, as a business entity ``which operates
                primarily within the United States.'' (13 CFR 121.105(a)). However, no
                regulatory flexibility analysis is required if the head of an agency
                certifies the rule would not have a significant economic impact on a
                substantial number of small entities. SBREFA amended the Regulatory
                Flexibility Act to require Federal agencies to provide a statement of
                the factual basis for certifying that a rule would not have a
                significant economic impact on a substantial number of small entities.
                 NHTSA has considered the effects of this proposal under the
                Regulatory Flexibility Act. I certify that this proposal will not have
                a significant economic impact on a substantial number of small
                entities. This proposal would directly impact the government, as it
                affects only the test procedures NHTSA uses in its FMVSSs and
                regulations that reference tire performance. It affects manufacturers
                of tires and of motor vehicles only to the
                [[Page 42770]]
                extent those manufacturers choose to test their products in the manner
                NHTSA would test them. They are not required to use the test procedures
                NHTSA uses.
                 Although we believe some entities producing tires or vehicles that
                would be tested by NHTSA using procedures that use the 16-inch SRTT are
                considered small businesses, we do not believe this proposal will have
                a significant economic impact on those manufacturers. First, the small
                manufacturers are not required to use the SRTT in certifying their
                products. Second, for manufacturers choosing to use the 16-inch SRTT to
                test their products, this proposal would result in a cost increase of
                only $35 per tire to entities currently purchasing the 14-inch SRTT to
                assess their products. We do not believe this cost increase is
                significant. Finally, for the changes to the UTQGS, because NHTSA is
                using a conversion factor to keep the rating scale used with the 14-
                inch SRTT and 16-inch SRTT identical, ratings of a particular line of
                tires should not be affected by this proposed rule. For FMVSS changes,
                NHTSA has determined an equivalent level of surface friction when
                evaluating PBC with the 16-inch SRTT in place of the 14-inch SRTT, so
                the change to the standard reference test tire should not change the
                performance of current tires or vehicles.
                C. Executive Order 13132 (Federalism)
                 NHTSA has examined this proposal pursuant to Executive Order 13132
                (64 FR 43255, August 10, 1999) and concluded that no additional
                consultation with States, local governments or their representatives is
                mandated beyond the rulemaking process. The agency has concluded that
                the rulemaking would not have sufficient federalism implications to
                warrant consultation with State and local officials or the preparation
                of a federalism summary impact statement. The proposal would not have
                ``substantial direct effects on the States, on the relationship between
                the national government and the States, or on the distribution of power
                and responsibilities among the various levels of government.''
                 NHTSA rules can preempt in two ways. First, the National Traffic
                and Motor Vehicle Safety Act contains an express preemption provision:
                When a motor vehicle safety standard is in effect under this chapter, a
                State or a political subdivision of a State may prescribe or continue
                in effect a standard applicable to the same aspect of performance of a
                motor vehicle or motor vehicle equipment only if the standard is
                identical to the standard prescribed under this chapter. 49 U.S.C.
                30103(b)(1). It is this statutory command by Congress that preempts any
                non-identical State legislative and administrative law addressing the
                same aspect of performance.
                 The express preemption provision described above is subject to a
                savings clause under which ``[c]ompliance with a motor vehicle safety
                standard prescribed under this chapter does not exempt a person from
                liability at common law.'' 49 U.S.C. 30103(e). Pursuant to this
                provision, State common law tort causes of action against motor vehicle
                manufacturers that might otherwise be preempted by the express
                preemption provision are generally preserved. However, the Supreme
                Court has recognized the possibility, in some instances, of implied
                preemption of such State common law tort causes of action by virtue of
                NHTSA's rules, even if not expressly preempted. This second way that
                NHTSA rules can preempt is dependent upon there being an actual
                conflict between an FMVSS and the higher standard that would
                effectively be imposed on motor vehicle manufacturers if someone
                obtained a State common law tort judgment against the manufacturer,
                notwithstanding the manufacturer's compliance with the NHTSA standard.
                Because most NHTSA standards established by an FMVSS are minimum
                standards, a State common law tort cause of action that seeks to impose
                a higher standard on motor vehicle manufacturers will generally not be
                preempted. However, if and when such a conflict does exist--for
                example, when the standard at issue is both a minimum and a maximum
                standard--the State common law tort cause of action is impliedly
                preempted. See Geier v. American Honda Motor Co., 529 U.S. 861 (2000).
                 Pursuant to Executive Orders 13132 and 12988, NHTSA has considered
                whether this proposed rule could or should preempt State common law
                causes of action. The agency's ability to announce its conclusion
                regarding the preemptive effect of one of its rules reduces the
                likelihood that preemption will be an issue in any subsequent tort
                litigation.
                 To this end, the agency has examined the nature (e.g., the language
                and structure of the regulatory text) and objectives of this proposed
                rule and finds that this proposal would affect only minimum safety
                standards (and only insofar as how NHTSA would conduct compliance
                testing under those standards). As such, NHTSA does not intend that
                this proposed rule preempt State tort law that would effectively impose
                a higher standard on motor vehicle manufacturers than that established
                by the affected FMVSSs. Establishment of a higher standard by means of
                State tort law would not conflict with the minimum standards affected
                by this proposal. Without any conflict, there could not be any implied
                preemption of a State common law tort cause of action. Aspects of this
                proposed rule would amend 49 CFR part 575, which is not a safety
                standard but an information program to assist consumers in making
                informed decisions when purchasing tires. The 14-inch SRTT is used as
                part of the determination of a tire's treadwear rating. This proposed
                change would not impose any requirements on anyone.
                D. Executive Order 12988 (Civil Justice Reform)
                 With respect to the review of the promulgation of a new regulation,
                section 3(b) of Executive Order 12988, ``Civil Justice Reform'' (61 FR
                4729; Feb. 7, 1996), requires that Executive agencies make every
                reasonable effort to ensure that the regulation: (1) Clearly specifies
                the preemptive effect; (2) clearly specifies the effect on existing
                Federal law or regulation; (3) provides a clear legal standard for
                affected conduct, while promoting simplification and burden reduction;
                (4) clearly specifies the retroactive effect, if any; (5) specifies
                whether administrative proceedings are to be required before parties
                file suit in court; (6) adequately defines key terms; and (7) addresses
                other important issues affecting clarity and general draftsmanship
                under any guidelines issued by the Attorney General. This document is
                consistent with that requirement.
                 Pursuant to this order, NHTSA notes as follows. The issue of
                preemption is discussed above. NHTSA notes further that there is no
                requirement that individuals submit a petition for reconsideration or
                pursue other administrative proceedings before they may file suit in
                court.
                E. Protection of Children From Environmental Health and Safety Risks
                 Executive Order 13045, ``Protection of Children from Environmental
                Health and Safety Risks'' (62 FR 19855, April 23, 1997), applies to any
                rule that: (1) Is determined to be ``economically significant'' as
                defined under Executive Order 12866, and (2) concerns an environmental,
                health, or safety risk that the agency has reason to believe may have a
                disproportionate effect on children. If the regulatory action meets
                [[Page 42771]]
                both criteria, the agency must evaluate the environmental health or
                safety effects of the planned rule on children, and explain why the
                planned regulation is preferable to other potentially effective and
                reasonably feasible alternatives considered by the agency.
                 This proposal is not economically significant under E.O. 12866.
                Further, it is part of a rulemaking that is not expected to have a
                disproportionate health or safety impact on children. Consequently, no
                further analysis is required under Executive Order 13045.
                F. Paperwork Reduction Act
                 Under the Paperwork Reduction Act of 1995 (PRA), a person is not
                required to respond to a collection of information by a Federal agency
                unless the collection displays a valid Office of Management and Budget
                (OMB) control number. There is not any information collection
                requirement associated with this proposal.
                G. Incorporation by Reference
                 Under regulations issued by the Office of the Federal Register (1
                CFR 51.5(a)), an agency, as part of a proposed rule that includes
                material incorporated by reference, must summarize material that is
                proposed to be incorporated by reference and must discuss the ways the
                material proposed to be incorporated by reference is reasonably
                available to interested parties or how the agency worked to make
                materials available to interested parties.
                 This proposed rule would incorporate by reference ASTM F2493,
                ``Standard Specification for P225/60R16 97S Radial Standard Reference
                Test Tire,'' to replace the existing incorporation by reference of ASTM
                E1136, which is a 14-inch standard reference test tire. As discussed
                earlier in this document, the ASTM F2493 is a standard reference test
                tire that is not used for general use, but, as its name suggests, is
                used for testing. The ASTM F2493 standard reference test tire is
                primarily used for evaluating surface friction (traction). The standard
                reference test tire specifications include, among other things, size,
                design, construction, and materials requirements.
                 This proposed rule would also update an existing incorporation by
                reference of ASTM E1337, ``Standard Test Method for Determining
                Longitudinal Peak Braking Coefficient (PBC) of Paved Surfaces Using
                Standard Reference Test Tire.'' ASTM E1337 is a standard test method
                for evaluating peak braking coefficient of a test surface using a
                standard reference test tire using a trailer towed by a vehicle. NHTSA
                uses this method to evaluate test surfaces for conducting compliance
                test procedures for its braking and electronic stability control
                standards. The 2019 version of ASTM E1337 specifies that the test may
                be conducted using the 16-inch SRTT and includes correlation data for
                converting testing using the 14-inch SRTT to the 16-inch SRTT and vice
                versa.
                 Finally, this proposed rule would update an existing incorporation
                by reference of ASTM F1805, ``Standard Test Method for Single Wheel
                Driving Traction in a Straight Line on Snow- and Ice-Covered
                Surfaces.'' ASTM F1805 is a test method for measuring the traction of
                tires on snow- or ice-covered surfaces using an instrumented four-wheel
                drive vehicle with a single test wheel capable of measure tire
                performance. NHTSA uses ASTM F1805 as part of its criteria for
                determining whether a tire may be considered a ``snow tire'' under its
                light vehicle tire standards. The 2020 version of F1805 specifies that
                the test may be conducted using the 16-inch SRTT and includes
                correlation data for converting testing using the 14-inch SRTT to the
                16-inch SRTT and vice versa.
                 The ASTM standards proposed for incorporation by reference in this
                NPRM are available for review at NHTSA's headquarters in Washington,
                DC, and for purchase from ASTM International. The ASTM standards that
                are currently incorporated by reference (and which would be replaced
                under this proposal) are available for review at NHTSA or at ASTM
                International's online reading room.\20\ If this proposal is adopted as
                a final rule, NHTSA anticipates that ASTM International would update
                its reading room to include these standards.
                ---------------------------------------------------------------------------
                 \20\ https://www.astm.org/READINGLIBRARY/.
                ---------------------------------------------------------------------------
                H. National Technology Transfer and Advancement Act
                 Section 12(d) of the National Technology Transfer and Advancement
                Act (NTTAA) requires NHTSA to evaluate and use existing voluntary
                consensus standards in its regulatory activities unless doing so would
                be inconsistent with applicable law (e.g., the statutory provisions
                regarding NHTSA's vehicle safety authority) or otherwise impractical.
                Voluntary consensus standards are technical standards developed or
                adopted by voluntary consensus standards bodies. Technical standards
                are defined by the NTTAA as ``performance-based or design-specific
                technical specification and related management systems practices.''
                They pertain to ``products and processes, such as size, strength, or
                technical performance of a product, process or material.''
                 Examples of organizations generally regarded as voluntary consensus
                standards bodies include ASTM International, the Society of Automotive
                Engineers (SAE), and the American National Standards Institute (ANSI).
                If NHTSA does not use available and potentially applicable voluntary
                consensus standards, we are required by the Act to provide Congress,
                through OMB, an explanation of the reasons for not using such
                standards.
                 As discussed above, both standard reference test tires are based on
                specifications published by ASTM International. Thus, this rulemaking
                accords with the requirements of the NTTAA.
                I. Unfunded Mandates Reform Act
                 Section 202 of the Unfunded Mandates Reform Act of 1995 (UMRA)
                requires Federal agencies to prepare a written assessment of the costs,
                benefits, and other effects of proposed or final rules that include a
                Federal mandate likely to result in the expenditure by State, local, or
                tribal governments, in the aggregate, or by the private sector, of more
                than $100 million annually (adjusted for inflation with base year of
                1995). Before promulgating a NHTSA rule for which a written statement
                is needed, section 205 of the UMRA generally requires the agency to
                identify and consider a reasonable number of regulatory alternatives
                and adopt the least costly, most cost-effective, or least burdensome
                alternative that achieves the objectives of the rule. The provisions of
                section 205 do not apply when they are inconsistent with applicable
                law. Moreover, section 205 allows the agency to adopt an alternative
                other than the least costly, most cost-effective, or least burdensome
                alternative if the agency publishes with the final rule an explanation
                of why that alternative was not adopted.
                 This proposal would not result in any expenditure by State, local,
                or tribal governments or the private sector of more than $100 million,
                adjusted for inflation.
                J. National Environmental Policy Act
                 NHTSA has analyzed this rulemaking action for the purposes of the
                National Environmental Policy Act. The agency has determined that
                implementation of this action would not have any significant impact on
                the quality of the human environment.
                K. Regulation Identifier Number (RIN)
                 The Department of Transportation assigns a regulation identifier
                number
                [[Page 42772]]
                (RIN) to each regulatory action listed in the Unified Agenda of Federal
                Regulations. The Regulatory Information Service Center publishes the
                Unified Agenda in April and October of each year. You may use the RIN
                contained in the heading at the beginning of this document to find this
                action in the Unified Agenda.
                List of Subjects
                49 CFR Part 571
                 Imports, Incorporation by reference, Motor vehicle safety,
                Reporting and recordkeeping requirements, Tires.
                49 CFR Part 575
                 Consumer protection, Incorporation by reference, Motor vehicle
                safety, Reporting and recordkeeping requirements, Tires.
                 In consideration of the foregoing, NHTSA proposes to amend 49 CFR
                parts 571 and 575 as follows:
                PART 571--FEDERAL MOTOR VEHICLE SAFETY STANDARDS
                0
                1. The authority citation for part 571 of title 49 continues to read as
                follows:
                 Authority: 49 U.S.C. 322, 30111, 30115, 30117, and 30166;
                delegation of authority at 49 CFR 1.95.
                0
                2. Amend Sec. 571.5 by revising paragraphs (d)(33) through (35) to
                read as follows:
                Sec. 571.5 Matter incorporated by reference.
                * * * * *
                 (d) * * *
                 (33) ASTM E1337-19, ``Standard Test Method for Determining
                Longitudinal Peak Braking Coefficient (PBC) of Paved Surfaces Using
                Standard Reference Test Tire,'' approved December 1, 2019, into
                Sec. Sec. 571.105; 571.121; 571.122; 571.126; 571.135; 571.136;
                571.500.
                 (34) ASTM F1805-20, ``Standard Test Method for Single Wheel Driving
                Traction in a Straight Line on Snow- and Ice-Covered Surfaces,''
                approved May 1, 2020, into Sec. 571.139.
                 (35) ASTM F2493-19, ``Standard Specification for P225/60R16 97S
                Radial Standard Reference Test Tire,'' approved Oct. 1, 2019, into
                Sec. Sec. 571.105; 571.121; 571.122; 571.126; 571.135; 571.136;
                571.139; 571.500.
                * * * * *
                0
                3. Amend Sec. 571.105 by removing paragraphs S6.9.2(a) and S6.9.2(b)
                and adding paragraph S6.9.2 to read as follows:
                Sec. 571.105 Standard No. 105; Hydraulic and electric brake systems.
                * * * * *
                 S6.9.2 (a) For vehicles with a GVWR greater than 10,000 pounds,
                road tests (excluding stability and control during braking tests) are
                conducted on a 12-foot-wide, level roadway, having a peak friction
                coefficient of 1.02 when measured using an ASTM F2493-19 (incorporated
                by reference, see Sec. 571.5), standard reference test tire, in
                accordance with ASTM E1337-19 (incorporated by reference, see Sec.
                571.5), at a speed of 40 mph, without water delivery. Burnish stops are
                conducted on any surface. The parking brake test surface is clean, dry,
                smooth, Portland cement concrete.
                 (b) For vehicles with a GVWR greater than 10,000 pounds, stability
                and control during braking tests are conducted on a 500-foot-radius
                curved roadway with a wet level surface having a peak friction
                coefficient of 0.55 when measured on a straight or curved section of
                the curved roadway using an ASTM F2493-19 standard reference tire, in
                accordance with ASTM E1337-19 at a speed of 40 mph, with water
                delivery.
                * * * * *
                0
                4. Amend Sec. 571.121 by revising paragraphs S5.3.1.1 introductory
                text, S5.3.6.1, S5.7.1, S6.1.7, Table I, Table II, and Table IIa to
                read as follows:
                Sec. 571.121 Standard No. 121; Air brake systems.
                * * * * *
                 S5.3.1.1 Stop the vehicle from 60 mph on a surface with a peak
                friction coefficient of 1.02 with the vehicle loaded as follows:
                * * * * *
                 S5.3.6.1 Using a full-treadle brake application for the duration of
                the stop, stop the vehicle from 30 mph or 75 percent of the maximum
                drive-through speed, whichever is less, on a 500-foot radius curved
                roadway with a wet level surface having a peak friction coefficient of
                0.55 when measured on a straight or curved section of the curved
                roadway using an ASTM F2493-19 (incorporated by reference, see Sec.
                571.5) standard reference tire, in accordance with ASTM E1337-19
                (incorporated by reference, see Sec. 571.5), at a speed of 40 mph,
                with water delivery.
                * * * * *
                 S5.7.1 Emergency brake system performance. When stopped six times
                for each combination of weight and speed specified in S5.3.1.1, except
                for a loaded truck tractor with an unbraked control trailer, on a road
                surface having a PFC of 1.02, with a single failure in the service
                brake system of a part designed to contain compressed air or brake
                fluid (except failure of a common valve, manifold, brake fluid housing,
                or brake chamber housing), the vehicle shall stop at least once in not
                more than the distance specified in Column 5 of Table II, measured from
                the point at which movement of the service brake control begins, except
                that a truck-tractor tested at its unloaded vehicle weight plus up to
                1,500 pounds shall stop at least once in not more than the distance
                specified in Column 6 of Table II. The stop shall be made without any
                part of the vehicle leaving the roadway, and with unlimited wheel
                lockup permitted at any speed.
                * * * * *
                 S6.1.7 Unless otherwise specified, stopping tests are conducted on
                a 12-foot wide level, straight roadway having a peak friction
                coefficient of 1.02. For road tests in S5.3, the vehicle is aligned in
                the center of the roadway at the beginning of a stop. Peak friction
                coefficient is measured using an ASTM F2493-19 standard reference test
                tire (see ASTM F2493-19 (incorporated by reference, see Sec. 571.5))
                in accordance with ASTM E1337-19 (incorporated by reference, see Sec.
                571.5), at a speed of 40 mph, without water delivery for the surface
                with PFC of 1.02, and with water delivery for the surface with PFC of
                0.55.
                * * * * *
                 Table I--Stopping Sequence
                ------------------------------------------------------------------------
                 Single unit
                 Truck tractors trucks and
                 buses
                ------------------------------------------------------------------------
                Burnish (S6.1.8)........................ 1 1
                Stability and Control at GVWR (S5.3.6).. 2 N/A
                Stability and Control at LLVW (S5.3.6).. 3 5
                Manual Adjustment of Brakes............. 4 N/A
                60 mph Service Brake Stops at GVWR 5 2
                 (S5.3.1)...............................
                60 mph Emergency Service Brake Stops at N/A 3
                 GVWR (S5.7.1)..........................
                [[Page 42773]]
                
                Parking Brake Test at GVWR (S5.6)....... 6 4
                Manual Adjustment of Brakes............. 7 6
                60 mph Service Brake Stops at LLVW 8 7
                 (S5.3.1)...............................
                60 mph Emergency Service Brake Stops at 9 8
                 LLVW (S5.7.1)..........................
                Parking Brake Test at LLVW (S5.6)....... 10 9
                Final Inspection........................ 11 10
                ------------------------------------------------------------------------
                 Table II--Stopping Distance in Feet
                --------------------------------------------------------------------------------------------------------------------------------------------------------
                 Service brake Emergency brake
                 Vehicle speed in miles per hour -------------------------------------------------------------------------------------------------------
                 (1) (2) (3) (4) (5) (6) (7) (8)
                --------------------------------------------------------------------------------------------------------------------------------------------------------
                30.............................................. 70 78 65 78 84 61 170 186
                35.............................................. 96 106 89 106 114 84 225 250
                40.............................................. 125 138 114 138 149 108 288 325
                45.............................................. 158 175 144 175 189 136 358 409
                50.............................................. 195 216 176 216 233 166 435 504
                55.............................................. 236 261 212 261 281 199 520 608
                60.............................................. 280 310 250 310 335 235 613 720
                --------------------------------------------------------------------------------------------------------------------------------------------------------
                Note:
                (1) Loaded and Unloaded Buses.
                (2) Loaded Single-Unit Trucks.
                (3) Loaded Tractors with Two Axles; or with Three Axles and a GVWR of 70,000 lbs. or less; or with Four or More Axles and a GVWR of 85,000 lbs. or less.
                 Tested with an Unbraked Control Trailer.
                (4) Loaded Tractors with Three Axles and a GVWR greater than 70,000 lbs.; or with Four or More Axles and a GVWR greater than 85,000 lbs. Tested with an
                 Unbraked Control Trailer.
                (5) Unloaded Single-Unit Trucks.
                (6) Unloaded Tractors (Bobtail).
                (7) All Vehicles except Tractors, Loaded and Unloaded.
                (8) Unloaded Tractors (Bobtail).
                 Table IIa--Stopping Distance in Feet: Optional Requirements for: (1) Three-Axle Tractors With a Front Axle That
                Has a GAWR of 14,600 Pounds or Less, and With Two Rear Drive Axles That Have a Combined GAWR of 45,000 Pounds or
                 Less, Manufactured Before August 1, 2011; and (2) All Other Tractors Manufactured Before August 1, 2013
                ----------------------------------------------------------------------------------------------------------------
                 Service Brake Emergency Brake
                 Vehicle speed in miles per hour -----------------------------------------------------------------------------
                 (1) (2) (3) (4) (5) (6)
                ----------------------------------------------------------------------------------------------------------------
                30................................ 70 78 84 89 170 186
                35................................ 96 106 114 121 225 250
                40................................ 125 138 149 158 288 325
                45................................ 158 175 189 200 358 409
                50................................ 195 216 233 247 435 504
                55................................ 236 261 281 299 520 608
                60................................ 280 310 335 355 613 720
                ----------------------------------------------------------------------------------------------------------------
                Note: (1) Loaded and unloaded buses; (2) Loaded single unit trucks; (3) Unloaded truck tractors and single unit
                 trucks; (4) Loaded truck tractors tested with an unbraked control trailer; (5) All vehicles except truck
                 tractors; (6) Unloaded truck tractors.
                * * * * *
                0
                5. Amend Sec. 571.122 by revising paragraphs S6.1.1.1, S6.1.1.2,
                S6.1.1.3, and S6.9.7.1(a) to read as follows:
                Sec. 571.122 Standard No. 122; Motorcycle brake systems.
                * * * * *
                 S6.1.1.1 High friction surface. A high friction surface is used for
                all dynamic brake tests excluding the ABS tests where a low-friction
                surface is specified. The high-friction surface test area is a clean,
                dry and level surface, with a gradient of =0.90.
                * * * * *
                0
                6. Amend Sec. 571.126 by revising paragraph S6.2.2 to read as follows:
                Sec. 571.126 Standard No. 126; Electronic stability control systems
                for light vehicles.
                * * * * *
                [[Page 42774]]
                 S6.2.2 The road test surface must produce a peak friction
                coefficient (PFC) of 1.02 when measured using an ASTM F2493-19
                (incorporated by reference, see Sec. 571.5) standard reference test
                tire, in accordance with ASTM E1337-19 (incorporated by reference, see
                Sec. 571.5) at a speed of 64.4 km/h (40 mph), without water delivery.
                * * * * *
                0
                7. Amend Sec. 571.135 by revising paragraphs S6.2.1, S7.4.3(f),
                S7.5.2(f), S7.6.2(f), S7.7.3(f), S7.8.2(f), S7.9.2(f), S7.10.3(e), and
                S7.11.3(f) to read as follows:
                Sec. 571.135 Standard No. 135; Light vehicle brake systems.
                * * * * *
                 S6.2.1 Unless otherwise specified, the road test surface produces a
                peak friction coefficient (PFC) of 1.02 when measured using an ASTM
                F2493-19 (incorporated by reference, see Sec. 571.5) standard
                reference test tire, in accordance with ASTM E1337-19 (incorporated by
                reference, see Sec. 571.5), at a speed of 64.4 km/h (40 mph), without
                water delivery.
                * * * * *
                 S7.4.3 * * *
                 (f) Test surface: PFC of at least 1.02.
                * * * * *
                 S7.5.2 * * *
                 (f) Test surface: PFC of 1.02.
                * * * * *
                 S7.6.2 * * *
                 (f) Test surface: PFC of 1.02.
                * * * * *
                 S7.7.3 * * *
                 (f) Test surface: PFC of 1.02.
                * * * * *
                 S7.8.2 * * *
                 (f) Test surface: PFC of 1.02.
                * * * * *
                 S7.9.2 * * *
                 (f) Test surface: PFC of 1.02.
                * * * * *
                 S7.10.3 * * *
                 (e) Test surface: PFC of 1.02.
                * * * * *
                 S7.11.3 * * *
                 (f) Test surface: PFC of 1.02.
                * * * * *
                0
                8. Amend Sec. 571.136 by revising paragraph S6.2.2 to read as follows:
                Sec. 571.136 Standard No. 136; Electronic stability control systems
                for heavy vehicles.
                * * * * *
                 S6.2.2 The road test surface produces a peak friction coefficient
                (PFC) of 1.02 when measured using an ASTM F2493-19 standard reference
                test tire, in accordance with ASTM E1337-19, at a speed of 64.4 km/h
                (40 mph), without water delivery (both documents incorporated by
                reference, see Sec. 571.5).
                * * * * *
                0
                9. Amend Sec. 571.139 by revising the definition of ``Snow tire'' in
                S3 to read as follows:
                Sec. 571.139 Standard No. 139; New pneumatic radial tires for light
                vehicles.
                * * * * *
                 S3 * * *
                 Snow tire means a tire that attains a traction index equal to or
                greater than 112, compared to the ASTM F2493-19 (incorporated by
                reference, see Sec. 571.5) Standard Reference Test Tire when using the
                snow traction test on the medium pack snow surface as described in ASTM
                F1805-20 (incorporated by reference, see Sec. 571.5), and that is
                marked with an Alpine Symbol specified in S5.5(i) on at least one
                sidewall.
                * * * * *
                0
                10. Amend Sec. 571.500 by revising paragraph S6.2.1 to read as
                follows:
                Sec. 571.500 Standard No. 500; Low-speed vehicles.
                * * * * *
                 S6.2.1 Pavement friction. Unless otherwise specified, the road test
                surface produces a peak friction coefficient (PFC) of 1.02 when
                measured using a standard reference test tire that meets the
                specifications of ASTM F2493-19, in accordance with ASTM E1337-19, at a
                speed of 64.4 km/h (40.0 mph), without water delivery (both
                incorporated by reference; see Sec. 571.5).
                * * * * *
                PART 575--CONSUMER INFORMATION
                0
                11. The authority citation for part 575 of title 49 continues to read
                as follows:
                 Authority: 49 U.S.C. 32302, 32304A, 30111, 30115, 30117, 30123,
                30166, 30181, 30182, 30183, and 32908, Pub. L. 104-414, 114 Stat.
                1800, Pub. L. 109-59, 119 Stat. 1144, Pub. L. 110-140, 121 Stat.
                1492, 15 U.S.C. 1232(g); delegation of authority at 49 CFR 1.95.
                0
                12. Amend Sec. 575.3 by revising paragraph (c) to read as follows:
                Sec. 575.3 Matter incorporated by reference.
                * * * * *
                 (c) ASTM International (ASTM), 100 Barr Harbor Drive, P.O. Box
                C700, West Conshohocken, PA 19428-2959, 610-832-9500, https://www.astm.org/.
                 (1) ASTM E 501-08 (``ASTM E 501''), ``Standard Specification for
                Standard Rib Tire for Pavement Skid-Resistance Tests'' (June 2008), IBR
                approved for Sec. Sec. 575.104 and 575.106.
                 (2) ASTM F2493-19 (``ASTM F2493''), ``Standard Specification for
                P225/60R16 97S Radial Standard Reference Test Tire,'' (approved Oct. 1,
                2019), IBR approved for Sec. 575.104.
                * * * * *
                0
                13. Amend Sec. 575.104 by revising paragraphs (e)(2)(viii)
                introductory text, (e)(2)(viii)(A) through (E), and (e)(2)(ix)(A)(2),
                the note to paragraph (e)(2)(ix)(C), and paragraph (e)(2)(ix)(F) to
                read as follows:
                Sec. 575.104 Uniform tire quality grading standards.
                * * * * *
                 (e) * * *
                 (2) * * *
                 (viii) Drive the convoy on the test roadway for 16 circuits
                (approximately 6,400 miles).
                 (A) After every circuit (approximately 400 miles), rotate each
                vehicle's tires by moving each front tire to the same side of the rear
                axle and each rear tire to the opposite side of the front axle.
                Visually inspect each tire for treadwear anomalies.
                 (B) After every second circuit (approximately 800 miles), rotate
                the vehicles in the convoy by moving the last vehicle to the lead
                position. Do not rotate driver positions within the convoy. In four-car
                convoys, vehicle one shall become vehicle two, vehicle two shall become
                vehicle three, vehicle three shall become vehicle four, and vehicle
                four shall become vehicle one.
                 (C) After every second circuit (approximately 800 miles), if
                necessary, adjust wheel alignment to the midpoint of the vehicle
                manufacturer's specification, unless adjustment to the midpoint is not
                recommended by the manufacturer; in that case, adjust the alignment to
                the manufacturer's recommended setting. In all cases, the setting is
                within the tolerance specified by the manufacturer of the alignment
                machine.
                 (D) After every second circuit (approximately 800 miles), if
                determining the projected mileage by the 9-point method set forth in
                paragraph (e)(2)(ix)(A)(1) of this section, measure the average tread
                depth of each tire following the procedure set forth in paragraph
                (e)(2)(vi) of this section.
                 (E) After every fourth circuit (approximately 1,600 miles), move
                the complete set of four tires to the following vehicle. Move the tires
                on the last vehicle to the lead vehicle. In moving the tires, rotate
                them as set forth in paragraph (e)(2)(viii)(A) of this section.
                * * * * *
                 (ix) * * *
                 (A) * * *
                 (2) Two-point arithmetical method. (i) For each course monitoring
                and
                [[Page 42775]]
                candidate tire in the convoy, using the average tread depth
                measurements obtained in accordance with paragraphs (e)(2)(vi) and
                (e)(2)(viii)(F) of this section and the corresponding mileages as data
                points, determine the slope (m) of the tire's wear in mils of tread
                depth per 1,000 miles by the following formula:
                [GRAPHIC] [TIFF OMITTED] TP05AU21.039
                Where:
                Yo = average tread depth after break-in, mils.
                Y1 = average tread depth after 16 circuits (approximately 6,400
                miles), mils.
                Xo = 0 miles (after break-in).
                X1 = Total mileage of travel after 16 circuits (approximately 6,400
                miles).
                 (ii) This slope (m) will be negative in value. The tire's wear rate
                is defined as the slope (m) expressed in mils per 1,000 miles.
                * * * * *
                 (C) * * *
                 Note to paragraph (e)(2)(ix)(C): The base wear rate for the
                course monitoring tires (CMTs) will be obtained by the Government by
                running the tire specified in ASTM F2493 (incorporated by reference,
                see Sec. 575.3) course monitoring tires for 16 circuits over the
                San Angelo, Texas, UTQGS test route 4 times per year, then using the
                average wear rate from the last 4 quarterly CMT tests for the base
                course wear rate calculation. Each new base course wear rate will be
                published in Docket No. NHTSA-2001-9395. The course monitoring tires
                used in a test convoy must be no more than one-year-old at the
                commencement of the test and must be used within four months after
                removal from storage.
                * * * * *
                 (F) Compute the grade (P) of the of the NHTSA nominal treadwear
                value for each candidate tire by using the following formula:
                [GRAPHIC] [TIFF OMITTED] TP05AU21.040
                Where base course wear raten = new base course wear rate,
                i.e., average treadwear of the last 4 quarterly course monitoring tire
                tests conducted by NHTSA.
                 Round off the percentage to the nearest lower 20-point increment.
                * * * * *
                 Issued in Washington, DC, under authority delegated in 49 CFR
                1.95 and 501.8.
                Steven S. Cliff,
                Acting Administrator.
                [FR Doc. 2021-15361 Filed 8-4-21; 8:45 am]
                BILLING CODE 4910-59-P
                

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