Notice2026-21843
Official Release of the MOVES6 Motor Vehicle Emissions Model for SIPs and Transportation Conformity
Primary source
Metadata and text below are from the Federal Register, a public-domain U.S. government work. Always verify the official published version before relying on it for any legal matter.
Published
October 27, 2026
Effective
October 27, 2026
Issuing agencies
Environmental Protection Agency
Abstract
The U.S. Environmental Protection Agency (EPA) is announcing the availability of the latest major release of the MOtor Vehicle Emission Simulator (MOVES) model, MOVES6. MOVES6 is the latest version of the EPA's state-of-the-science modeling tool for estimating emissions from cars, trucks, buses, and motorcycles based on the latest data and regulations. MOVES6 is available for use in State Implementation Plans (SIPs) and transportation conformity analyses. This notice starts a two-year grace period before MOVES6 will be required for use in transportation conformity determinations, both in new regional emissions analyses and in new hot-spot analyses.
Full Text
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<title>Federal Register, Volume 91 Issue 206 (Tuesday, October 27, 2026)</title>
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[Federal Register Volume 91, Number 206 (Tuesday, October 27, 2026)]
[Notices]
[Pages 67565-67570]
From the Federal Register Online via the Government Publishing Office [<a href="http://www.gpo.gov">www.gpo.gov</a>]
[FR Doc No: 2026-21843]
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ENVIRONMENTAL PROTECTION AGENCY
[FRL-13436-01-OAR]
Official Release of the MOVES6 Motor Vehicle Emissions Model for
SIPs and Transportation Conformity
AGENCY: Environmental Protection Agency (EPA).
ACTION: Notice of availability.
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SUMMARY: The U.S. Environmental Protection Agency (EPA) is announcing
[[Page 67566]]
the availability of the latest major release of the MOtor Vehicle
Emission Simulator (MOVES) model, MOVES6. MOVES6 is the latest version
of the EPA's state-of-the-science modeling tool for estimating
emissions from cars, trucks, buses, and motorcycles based on the latest
data and regulations. MOVES6 is available for use in State
Implementation Plans (SIPs) and transportation conformity analyses.
This notice starts a two-year grace period before MOVES6 will be
required for use in transportation conformity determinations, both in
new regional emissions analyses and in new hot-spot analyses.
DATES: The EPA's announcement of the MOVES6 emissions model for SIPs
and transportation conformity determinations in States other than
California is effective October 27, 2026. This announcement starts a
two-year transportation conformity grace period that ends on October
27, 2028. After this date, MOVES6 will be required for use as the
latest EPA emissions model for new transportation conformity analyses
other than California in both regional emissions analyses and in hot-
spot analyses.
FOR FURTHER INFORMATION CONTACT: For technical model questions
regarding the use of MOVES6, please email <a href="/cdn-cgi/l/email-protection#2a47455c4f596a4f5a4b044d455c"><span class="__cf_email__" data-cfemail="4e2321382b3d0e2b3e2f60292138">[email protected]</span></a>. For questions
about SIPs, contact Kaitlyn Leffert at <a href="/cdn-cgi/l/email-protection#ec80898a8a899e98c2878d8598809582ac899c8dc28b839a"><span class="__cf_email__" data-cfemail="ed81888b8b889f99c3868c8499819483ad889d8cc38a829b">[email protected]</span></a>. For
questions about transportation conformity, contact Aaron Letterly at
<a href="/cdn-cgi/l/email-protection#24484150504156485d0a4545564b4a644154450a434b52"><span class="__cf_email__" data-cfemail="a0ccc5d4d4c5d2ccd98ec1c1d2cfcee0c5d0c18ec7cfd6">[email protected]</span></a>.
SUPPLEMENTARY INFORMATION:
Preamble acronyms and abbreviations. Throughout this preamble, the
use of ``we,'' ``us,'' or ``our'' is intended to refer to the EPA. We
use multiple acronyms and terms in this preamble. While this list may
not be exhaustive, to ease the reading of this preamble and for
reference purposes, the EPA defines the following terms and acronyms
here:
ACT Advanced Clean Trucks
CO Carbon Monoxide
CAA Clean Air Act
CFR Code of Federal Regulations
CNG Compressed Natural Gas
DOE Department of Energy
DOT Department of Transportation
EMFAC EMissions FACtors
EPA Environmental Protection Agency
EV Electric Vehicle
FHWA Federal Highway Administration
FR Federal Register
FTA Federal Transit Administration
GHG Greenhouse Gas
HC Hydrocarbons
MPO Metropolitan Planning Organization
MOVES MOtor Vehicle Emission Simulator
MY Model Year
NAAQS National Ambient Air Quality Standards
NO<INF>2</INF> Nitrogen Dioxide
NO<INF>X</INF> Nitrogen Oxides
PM Particulate Matter
TIP Transportation Improvement Program
SIP State Implementation Plan
VMT Vehicle Miles Traveled
VOC Volatile Organic Compounds
Table of Contents
I. General Information
II. What is MOVES6?
III. SIPs and MOVES6
IV. Transportation Conformity and MOVES6
I. General Information
A. Does this action apply to me?
Entities potentially impacted by the approval of MOVES6 are those
that adopt, approve, or fund transportation plans, transportation
improvement programs (TIPs), or transportation projects as defined in
40 CFR 93.101 and those that develop and submit SIPs to the EPA.
Regulated categories and entities potentially affected by this action
include:
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Category Examples of regulated entities
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Local government....................... Local air quality and
transportation agencies,
including metropolitan
planning organizations (MPOs).
State government....................... State air quality and
transportation agencies.
Federal government..................... U.S. Department of
Transportation (Federal
Highway Administration (FHWA)
and Federal Transit
Administration (FTA)).
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This table is not intended to be exhaustive but rather provides a
guide for readers regarding entities likely to be affected by the
release of MOVES. Other entities not listed in the table could also be
affected. To determine whether your organization is affected by this
action, you should carefully examine the transportation conformity
applicability requirements in 40 CFR 93.102. If you have questions
regarding the applicability of this action to a particular entity,
consult the persons listed in the preceding FOR FURTHER INFORMATION
CONTACT section.
B. How can I get copies of MOVES6 and other related information?
The official version of the MOVES6 model and supporting
documentation are available on the EPA's MOVES website at: <a href="https://www.epa.gov/moves">https://www.epa.gov/moves</a>. Individuals who want to receive EPA announcements
related to the MOVES6 model can follow instructions linked from the
MOVES website at: <a href="https://www.epa.gov/moves/latest-version-motor-vehicle-emission-simulator-moves">https://www.epa.gov/moves/latest-version-motor-vehicle-emission-simulator-moves</a> to receive EPA email announcements
related to MOVES and MOVES guidance.
Available guidance on how to apply MOVES6 for SIPs and
transportation conformity purposes can be found on the EPA's
transportation conformity website, <a href="https://www.epa.gov/state-and-local-transportation/policy-and-technical-guidance-state-and-local-transportation">https://www.epa.gov/state-and-local-transportation/policy-and-technical-guidance-state-and-local-transportation</a>,\1\ including the ``MOVES6 Policy Guidance: Use of MOVES
for State Implementation Plan Development, Transportation Conformity,
General Conformity, and Other Purposes,'' \2\ referred to in this
notice as the ``MOVES6 Policy Guidance.'' This website also includes
the ``MOVES6 Technical Guidance: Using MOVES to Prepare Emission
Inventories in State Implementation Plans and Transportation
Conformity.'' \3\
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\1\ Interested parties can find these documents under the
``Emission Models and Conformity'' and ``Project-Level Conformity''
topics on this website.
\2\ EPA-403-B-26-001, October 2026.
\3\ EPA-403-B-26-002, October 2026.
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The EPA will continue to update these websites as other MOVES
support materials and guidance are developed or updated.
II. What is MOVES6?
MOVES6 is the EPA's latest official motor vehicle emissions model
for State and local agencies to estimate volatile organic compounds
(VOCs), nitrogen oxides (NO<INF>X</INF>), particulate matter
(PM<INF>2.5</INF> and PM<INF>10</INF>), carbon monoxide (CO), and other
pollutants and precursors from cars, trucks, buses, and motorcycles for
SIP purposes and transportation conformity determinations other than
California.\4\ MOVES6 represents the
[[Page 67567]]
sixth major release of the MOVES series of models.
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\4\ In California, a different onroad emissions model, the
EMissions FACtors (EMFAC) model, is used for regulatory purposes
instead of MOVES. MOVES can also model emissions in the District of
Columbia, Puerto Rico, and the U.S. Virgin Islands.
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MOVES is a flexible model using a variety of input and output
options, allowing more than one way to develop emissions estimates.
Like its predecessors, MOVES6 includes the capability to estimate
criteria pollutant and precursor emissions from vehicle exhaust and
evaporative emissions as well as brake wear and tire wear emissions.
Also, like previous versions, MOVES6 does not include the capability to
estimate emissions of re-entrained road dust. To estimate emissions
from re-entrained road dust, practitioners should continue to use the
latest approved methodologies.\5\
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\5\ See the EPA's Notice of Availability, Official Release of
the January 2011 AP-42 Method for Estimating Re-Entrained Road Dust
from Paved Roads (76 FR 6328; Feb. 4, 2011).
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The EPA is releasing MOVES6 to account for important legislative
and regulatory changes. On February 12, 2026, the EPA finalized the
Endangerment Finding Rescission Rule that repealed all greenhouse gas
(GHG) emission standards for light-, medium-, and heavy-duty on-highway
vehicles and engines.\6\ MOVES6 accounts for this change and also
accounts for the Congressional disapproval of the waiver for
California's Advanced Clean Trucks (ACT) regulations.\7\ MOVES6 also
accounts for legislation that reduced incentives for electric vehicles
(EVs) and EV charging infrastructure.\8\
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\6\ 91 FR 7686 (Feb. 18, 2026) (the ``Endangerment Finding
Rescission Rule'').
\7\ In 2025, Congress enacted joint resolutions of disapproval
under the Congressional Review Act for certain preemption waivers
that the EPA had previously issued pursuant to CAA section 209,
including ACT (see H.J. Res. 87). President Trump signed the
resolution into law (see Pub. L. 119-15, 139 Stat. 65 (June 12,
2025)). This resolution provides that the corresponding waiver
``shall have no force or effect.'' As a result, the EPA's prior
preemption waiver for ACT has no force or effect. Accordingly, ACT
is preempted by the CAA, meaning that a State can no longer enforce
or attempt to enforce the ACT regulations and that estimated
emissions reductions attributed to the ACT regulations cannot be
used for the CAA purposes of SIP development or conformity
determinations.
\8\ See Public Law 119-21, 139 Stat. 72 (July 4, 2025).
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Previous versions of the MOVES model (i.e., MOVES5 and MOVES4) both
accounted for the GHG vehicle standards in effect at the time those
models were released, projecting that GHG standards would be met
through greater adoption of EVs over time.\9\ However, these GHG
standards have since been rescinded.\10\ In MOVES6, the EPA updated
energy consumption rates and adjusted assumptions about the fraction of
EVs and other fuel types.\11\ MOVES6 still projects that some fraction
of vehicles are EVs in future years, but these fractions by year are
generally smaller than in MOVES5 and MOVES4. In addition, MOVES6
includes updated activity data and fixes incorrect values in MOVES5.
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\9\ See the EPA's Notice of Availability, Official release of
the MOVES5 Motor Vehicle Emissions Model for SIPs and Transportation
Conformity (89 FR 99862; Dec. 11, 2024). See also the EPA's Notice
of Availability, Official release of the MOVES4 Motor Vehicle
Emissions Model for SIPs and Transportation Conformity (88 FR 62567;
Sept. 12, 2023). MOVES3 does not include EVs in the default
information.
\10\ See 91 FR 7686 (Feb. 18, 2026).
\11\ The projections are based on the U.S. Department of Energy
(DOE), U.S. Energy Information Administration ``Annual Energy
Outlook 2025: Case Descriptions'' at 9 (explaining the alternate
transportation case description) at: <a href="https://www.eia.gov/outlooks/archive/aeo25/assumptions/pdf/case_descriptions.pdf">https://www.eia.gov/outlooks/archive/aeo25/assumptions/pdf/case_descriptions.pdf</a>.
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There are no changes to the MOVES interface since MOVES5. The
significant changes in MOVES6 are summarized below:
<bullet> EV fractions were reduced to account for the repeal of GHG
standards and reductions in incentives for EVs and EV infrastructure.
Medium- and heavy-duty EV fractions were also reduced to account for
Congressional disapproval of the waiver for California's ACT
regulations that included heavy-duty zero emission vehicle
requirements.
<bullet> Energy consumption rates for model year (MY) 2017-2024
were updated based on real-world data from the EPA's 2025 Automotive
Trends Report.\12\ Rates for MY 2025 and later continued these trends.
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\12\ See U.S. Environmental Protection Agency. (2026). The 2025
EPA Automotive Trends Report: Fuel Economy and Technology since
1975. EPA-420-R-26-001.
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<bullet> Historical and projected vehicle miles traveled (VMT) and
vehicle populations were updated using the latest data on school buses
and transit buses, as well as updated values from the U.S. Federal
Highway Administration (FHWA) Highway Statistics (2024) and the DOE
Annual Energy Outlook (2025).
<bullet> Emission rates were corrected to fix minor errors in
MOVES5. The fixes affected exhaust hydrocarbon (HC), NO<INF>X</INF>,
and PM from MYs 2031 and later medium-duty (Class 2b and 3) trucks, CO
from MYs 2027 and later light-duty cars and trucks, and tire wear from
all compressed natural gas (CNG) heavy-heavy-duty (Class 8) trucks.
<bullet> Gasoline properties in a few counties were updated to
account for new data and changes to local fuel requirements since
MOVES5.
As a result of all these changes, estimates of emissions from
MOVES6 may differ from earlier versions of MOVES. The net impact of
these changes on estimated emissions will depend on many factors,
including the specific area being modeled and the inputs used.
For additional information on the updates included in MOVES6,
please refer to the ``Overview of EPA's MOtor Vehicle Emission
Simulator (MOVES6),'' found at the EPA's MOVES website. Specific
information about MOVES6 inputs and algorithms can be found on the
EPA's websites for MOVES Onroad Technical Reports and MOVES Nonroad
Technical Reports.\13\
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\13\ For more information, see the EPA's MOVES website at:
<a href="https://www.epa.gov/moves">https://www.epa.gov/moves</a>.
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III. SIPs and MOVES6
The EPA has articulated the Agency's policy regarding the use of
MOVES6 in SIP development in the MOVES6 Policy Guidance. This notice
highlights certain aspects of the guidance, but State and local
governments should refer to the guidance for more detailed information
on how and when to use MOVES6 in reasonable further progress SIPs,
attainment demonstrations, maintenance plans, inventory updates, and
other SIP submissions.
The Clean Air Act (CAA) and implementation rules for the National
Ambient Air Quality Standards (NAAQS) describe how SIP inventories and
control measures should be based on the most current information and
applicable models available when a SIP is developed.\14\ Therefore,
States should use the latest version of MOVES and planning assumptions
available at the time that a SIP is developed to ensure the SIP is
based on the most accurate estimates of emissions possible. Now that
MOVES6 is available, it should be used in ozone, CO, PM, and nitrogen
dioxide (NO<INF>2</INF>) SIP development for all States other than
California as expeditiously as possible, as there is no grace period
for the use of MOVES6 in SIPs. For example, MOVES6 should be used if a
State is in the early stages of SIP development and significant work
has not yet occurred or if work has not yet started for a new SIP
requirement.
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\14\ See CAA section 172(c)(3). See also 81 FR 58029 (Aug. 24,
2016) and 83 FR 63022 (Dec. 6, 2018).
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The EPA also recognizes the time and level of effort involved in
SIP development. In cases in which State and local agencies have
already completed significant work on a SIP with MOVES5 or MOVES4 as of
the MOVES6 release, they may continue to rely on this earlier version.
For instance, SIP development may continue if a State has progressed
far enough along that
[[Page 67568]]
switching from a previous model version would create a significant
adverse impact on State resources (e.g., if attainment modeling has
already been completed with MOVES5 or MOVES4 prior to the MOVES6
release). However, as noted in section II of this notice, MOVES5 and
MOVES4 contain national default EV projections that do not reflect the
Endangerment Finding Rescission Rule or other updates in MOVES6. See
sections 1.5 and 2.1 of the MOVES6 Policy Guidance for more information
on using previous versions of MOVES in SIP development, including
details on how to adjust EV projections in MOVES5 and MOVES4.
States should consult with their EPA Regional Office if they have
questions about how MOVES6 affects SIPs under development in specific
nonattainment or maintenance areas. Early consultation can facilitate
the EPA's consideration of whether to make an adequacy finding for
transportation conformity purposes as well as the Agency's
consideration of a SIP submission.
The EPA does not require States to revise submitted SIPs or SIPs
that have already been approved simply because a new motor vehicle
emissions model is now available.\15\ States can, however, choose to
update these SIPs with MOVES6, for example, if it is determined that it
is appropriate to update motor vehicle emissions budgets (``budgets'')
with the model for future transportation conformity determinations.\16\
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\15\ See Sierra Club v. EPA, 356 F.3d. 296, 308 (D.C. Cir. 2004)
(``To require states to revise completed plans every time a new
model is announced would lead to significant costs and potentially
endless delays in the approval processes.'').
\16\ See 40 CFR 93.101, (definition of ``motor vehicle emissions
budget'').
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The EPA recognizes that States may have relied on the EV
assumptions in MOVES5 and MOVES4 in SIP development based on the
Agency's statements in previous versions of the MOVES Policy and
Technical Guidance. The EPA expects limited cases in which State and
local agencies have already completed significant work with MOVES5 or
MOVES4 and submitted a SIP prior to or shortly after the Endangerment
Finding Rescission Rule. When evaluating these SIP submittals, the EPA
will consider the latest MOVES model, assumptions, and guidance
information available to a State at the time it developed its SIP.
For complete explanations of how MOVES6 is to be implemented for
SIP purposes, refer to the MOVES6 Policy Guidance.
IV. Transportation Conformity and MOVES6
Transportation conformity is required under CAA section 176(c) to
ensure that federally funded or approved highway and transit activities
are consistent with (i.e., ``conform to'') the purpose of the SIP.
Conformity to the purpose of the SIP means that transportation
activities will not cause or contribute to new air quality violations,
worsen existing violations, or delay timely attainment of the relevant
NAAQS or any interim milestones.\17\ The EPA's transportation
conformity regulations establish the criteria and procedures for
determining whether metropolitan transportation plans, TIPs, and
federally supported highway and transit projects conform to the
SIP.\18\ Transportation conformity applies to designated nonattainment
and maintenance areas for transportation-related criteria pollutants:
ozone, PM<INF>2.5</INF>, PM<INF>10</INF>, CO, and NO<INF>2</INF>.\19\
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\17\ See 42 U.S.C. 7506(c).
\18\ See 40 CFR parts 51 and 93.
\19\ ``Maintenance areas'' are those areas initially designated
nonattainment for a criteria pollutant and subsequently redesignated
to attainment after 1990. Maintenance areas have SIPs developed
under CAA section 175A. See also 40 CFR 93.101.
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The EPA has articulated the Agency's policy regarding the use of
MOVES6 in transportation conformity determinations in the MOVES6 Policy
Guidance. This notice highlights certain aspects of the guidance, but
State and local governments should refer to the guidance for more
detailed information on how and when to use MOVES6 in transportation
conformity determinations.
In this notice, the EPA is announcing the availability of MOVES6
for use in transportation conformity determinations other than
California. The EPA is also establishing a two-year grace period before
MOVES6 will be required for use in regional emissions analyses for
transportation conformity determinations of transportation plans and
TIPs and in hot-spot analyses for project-level transportation
conformity determinations that use the EPA's emissions model.\20\ The
MOVES6 grace period for regional emissions and hot-spot analyses
applies to the use of MOVES6 and any future minor revisions that occur
during the grace period.
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\20\ The grace period also applies in the case that a regional
emissions analysis is done for a project not included in a
conforming transportation plan or TIP (i.e., a project in an
isolated rural area). See the transportation conformity regulations
at 40 CFR 93.101 for the definition of an isolated rural area and 40
CFR 93.109(g) for how conformity is done in an isolated rural area.
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This MOVES6 grace period is separate and distinct from the two-year
grace period established with the release of the previous version of
the model, MOVES5. The two-year grace period established by the EPA's
December 2024 MOVES5 Notice of Availability in the Federal Register is
unchanged by the release of MOVES6 and continues to be in effect until
December 11, 2026.\21\
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\21\ See 89 FR 99862 (Dec. 11, 2024).
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The EPA also notes that MOVES6 includes the latest information for
the national default projections of EVs, whereas the information in
earlier versions of MOVES5 and MOVES4 needs to be updated for new or
delayed analyses after the MOVES6 release.\22\ During the two-year
MOVES6 grace period, modelers beginning new analyses with MOVES5 may
not rely on MOVES5 national defaults for projections of EVs. See
additional information below in sections IV.C. and D. of this notice
and in the EPA's MOVES6 Policy Guidance.\23\
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\22\ See 40 CFR 93.110(a).
\23\ Modelers that begin new analyses using MOVES4 during the
MOVES5 grace period must also change the EV projections.
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The remainder of this section describes how the transportation
conformity grace period was determined and summarizes how it will be
implemented, including those circumstances in which the MOVES6 grace
period could be shorter than two years for regional emissions analyses.
However, for complete explanations regarding transportation conformity,
refer to the MOVES6 Policy Guidance.
A. Why is the EPA establishing a two-year transportation conformity
grace period?
CAA section 176(c)(1) states that ``. . . [t]he determination of
conformity shall be based on the most recent estimates of emissions,
and such estimates shall be determined from the most recent population,
employment, travel, and congestion estimates. . . .'' \24\
Additionally, the transportation conformity regulations require
conformity determinations to be based on ``the latest emission
estimation model available,'' and further state that this requirement
is satisfied if the most current version of the EPA's motor vehicle
emissions model is used in the conformity analysis.\25\ When the EPA
announces a new emissions model, such as MOVES6, the Agency establishes
a grace period before the model must be used for transportation
conformity purposes.\26\ In consultation with the
[[Page 67569]]
U.S. Department of Transportation (DOT), the EPA must consider the
degree of change in the emissions model and the effects of the new
model on the transportation planning process.\27\ The transportation
conformity regulations provide that the EPA will establish a grace
period for new emissions models of between three and 24 months.\28\
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\24\ 42 U.S.C. 7506(c)(1).
\25\ See 40 CFR 93.111.
\26\ See 40 CFR 93.111(b).
\27\ See 40 CFR 93.111(b)(2).
\28\ See 40 CFR 93.111(b)(1).
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The EPA articulated its intentions for establishing the length of a
grace period in the preamble to the 1993 transportation conformity
rule:
``EPA and DOT will consider extending the grace period if the
effects of the new emissions model are so significant that previous SIP
demonstrations of what emission levels are consistent with attainment
would be substantially affected. In such cases, States should have an
opportunity to revise their SIPs before MPOs must use the model's new
emissions factors.'' \29\
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\29\ See 58 FR 62211 (Nov. 24, 1993).
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In consultation with DOT, the EPA considered the degree of change
in MOVES6 and the effects of the new model on the transportation
planning process.\30\ The EPA considered the transition of State and
local transportation and air quality agencies to conduct and provide
technical support for analyses for MOVES6. Since 1993, the fundamental
purpose of 40 CFR 93.111(b) of the transportation conformity
regulations has been to provide a sufficient amount of time for MPOs
and other State and local agencies to learn and employ new emissions
models. The transition to a new emissions model involves preparing
input data and model output as well as considering how the model
affects regional emissions analysis results and whether SIP and/or
transportation plan/TIP changes are necessary.
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\30\ See 40 CFR 93.111(b)(2).
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The EPA provides guidance on how to run the latest MOVES version
for SIP and transportation conformity purposes with the release of the
model.\31\ Generally, existing guidance and training applies to MOVES6
as noted on the EPA's website, and the Agency will notify MOVES6 users
when updates to these materials are available. Training materials will
continue to address different levels of State and local expertise.
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\31\ Refer to the EPA's ``MOVES6 Technical Guidance: Using MOVES
to Prepare Emission Inventories for State Implementation Plans and
Transportation Conformity,'' EPA-403-B-26-002, October 2026,
available on the EPA's website at: <a href="https://www.epa.gov/moves/latest-version-motor-vehicle-emission-simulator-moves">https://www.epa.gov/moves/latest-version-motor-vehicle-emission-simulator-moves</a>.
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Upon consideration of these factors, the EPA is establishing a two-
year grace period, which begins today, October 27, 2026, and ends on
October 27, 2028, before MOVES6 needs to be used for new transportation
conformity analyses in States other than California.
B. Circumstances in Which the MOVES6 Grace Period Will Be Shorter Than
Two Years
The MOVES6 grace period for regional emissions analyses will be
shorter than two years for a given pollutant if an area revises its SIP
and motor vehicle emissions budgets with MOVES6 and such budgets have
been found adequate or approved into the SIP prior to the end of the
two-year grace period. In this case, the new regional emissions
analysis must use MOVES6 because the transportation conformity
determination would be demonstrating consistency with a MOVES6-based
budget.\32\
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\32\ See 40 CFR 93.111.
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Areas designated nonattainment or maintenance for more than one
pollutant may rely on both MOVES6 and MOVES5 to determine
transportation conformity for different pollutants during the MOVES6
grace period. In addition, the length of the MOVES6 grace period for
hot-spot analyses would not be affected by an early submission of
MOVES6-based budgets. The appropriate EPA Regional Office should be
consulted regarding situations in multi-pollutant areas.
C. Use of MOVES6 for Regional Emissions Analyses During the Grace
Period
During the transportation conformity grace period, areas should use
interagency consultation to examine how MOVES6 will impact their
regional emissions analyses and future transportation plan and TIP
conformity determinations.\33\ Areas should carefully consider whether
the SIP and budget(s) should be revised with MOVES6 or if
transportation plans and TIPs should be revised before the end of the
grace period. The transportation conformity regulations also provide
flexibility in that regional emissions analyses started with MOVES5
before or during the MOVES6 grace period can be completed using
MOVES5.\34\
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\33\ Isolated rural areas should also consider how future
regional emissions analyses will be affected when MOVES6 is
required, if such an analysis is anticipated.
\34\ See 40 CFR 93.111(c).
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It is also important that transportation conformity determinations
continue to meet the requirements for using the latest planning
assumptions.\35\ Under the transportation conformity regulations, the
latest planning assumptions must be used when the conformity analysis
begins, but if new information becomes available after that point, it
does not need to be included unless a significant delay in the analysis
occurs as determined through interagency consultation. As described in
section II of this notice, MOVES6 incorporates applicable Federal
vehicle standards, including the effects of the EPA's Endangerment
Finding Rescission Rule as well as other updates that provide the
latest information for the national default projections of EVs. Below
is an overview for meeting the latest planning assumptions requirements
during this model transition:
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\35\ See 40 CFR 93.110.
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<bullet> For transportation conformity analyses started before the
release of MOVES6, the national default EV projections in MOVES5 can be
used by transportation agencies as part of their latest planning
assumptions so long as the analysis has already begun (i.e., the
analysis was started prior to the MOVES6 release) and there is no
significant delay in the analysis.\36\
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\36\ See 40 CFR 93.110(a).
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<bullet> For transportation conformity determinations in which the
analysis starts after the release of MOVES6, modelers must either
update their MOVES5 modeling to include updated EV fraction projections
or use MOVES6.
When the MOVES6 grace period ends, MOVES6 will replace MOVES5 as
the latest EPA emissions model for all new transportation conformity
analyses. State and local agencies are encouraged to transition sooner
to MOVES6 to use the latest information and other model improvements.
See sections 1.5 and 3.5 of the MOVES6 Policy Guidance for further
details.
When the grace period ends on October 27, 2028, MOVES6 will become
the only EPA motor vehicle emissions model for regional emissions
analyses for transportation conformity in States other than California.
In general, this means that all new transportation plans and TIP
conformity determinations started after the end of the grace period
must be based on MOVES6, even if the SIP is based on MOVES5 or an older
version of the MOVES model.
D. Use of MOVES6 for Project-Level Hot-Spot Analyses During the
Conformity Grace Period
The MOVES6 grace period also applies to the use of MOVES6 for CO,
PM<INF>10</INF>, and PM<INF>2.5</INF> hot-spot analyses. The
transportation conformity regulations contain the requirements for when
a hot-spot analysis is required for project-
[[Page 67570]]
level conformity determinations.\37\ The transportation conformity
regulations provide flexibility for analyses started before the end of
the grace period. A conformity determination for a transportation
project may be based on a previous model if the analysis was begun
before the end of the grace period and if the final environmental
document for the project is issued no more than three years after the
issuance of the draft environmental document.\38\
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\37\ See 40 CFR 93.116 and 93.123. In CO nonattainment and
maintenance areas, a hot-spot analysis is required for all non-
exempt projects, with quantitative hot-spot analyses being required
for larger, congested intersections and other projects. In
PM<INF>2.5</INF> and PM<INF>10</INF> nonattainment and maintenance
areas, the transportation conformity regulations require that a
quantitative hot-spot analysis be completed for certain projects.
\38\ See 40 CFR 93.111(c).
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Project-level transportation conformity determinations in which the
hot-spot analysis has already begun (i.e., the analysis was started
prior to the MOVES6 release) with MOVES5 may have included the model's
national default EV projections. These transportation conformity
determinations may be completed because those EV projections were
relied on as the most recent assumptions when the analysis began. For
these conformity determinations, the interagency consultation process
should be used to confirm when the analysis began, the EV projections
used, and whether there is any delay in the analysis that would require
new EV projections to be included.
For CO, PM<INF>10</INF>, and PM<INF>2.5</INF> hot-spot analyses
that start during the MOVES6 grace period, project sponsors can choose
to use MOVES6 or MOVES5. If MOVES5 is used, modelers must update their
MOVES5 modeling to include updated EV fraction projections. Any new CO,
PM<INF>10</INF>, or PM<INF>2.5</INF> hot-spot analyses for
transportation conformity purposes begun after the end of the MOVES6
grace period must be based on MOVES6.
Interagency consultation must be used to evaluate and choose
model(s) and associated methods and assumptions to be used in
transportation conformity hot-spot analyses and regional emissions
analyses.\39\ For questions about how the MOVES grace periods apply in
a project-level conformity determination, contact your EPA Regional
Office.
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\39\ See 40 CFR 93.105(c)(1)(i).
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See the EPA's ``Project-level Conformity'' website, <a href="https://www.epa.gov/state-and-local-transportation/project-level-conformity-and-hot-spot-analyses">https://www.epa.gov/state-and-local-transportation/project-level-conformity-and-hot-spot-analyses</a>, for the latest information and guidance
documents for hot-spot analyses. See sections 1.5 and 3.7 of the MOVES6
Policy Guidance for further details.
Abigale D. Tardif,
Acting Assistant Administrator, Office of Air and Radiation.
[FR Doc. 2026-21843 Filed 10-26-26; 8:45 am]
BILLING CODE 6569-60-P
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