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Transportation Conformity Rule Amendments: Flexibility and Streamlining

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[Federal Register: August 15, 1997 (Volume 62, Number 158)]
[Rules and Regulations]
[Page 43779-43818]
From the Federal Register Online via GPO Access [wais.access.gpo.gov]
[DOCID:fr15au97-16]
_______________________________________________________________________

ENVIRONMENTAL PROTECTION AGENCY
40 CFR Parts 51 and 93
[FRL-5871-4]
RIN 2060-AG16

Transportation Conformity Rule Amendments: Flexibility and
Streamlining

AGENCY: Environmental Protection Agency (EPA).
ACTION: Final rule.

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SUMMARY: Today EPA promulgates a clarified and more flexible
transportation conformity rule. The conformity rule requires that
transportation plans, programs, and projects conform to state air
quality implementation plans (SIPs) and establishes the criteria and
procedures for determining whether or not they do. Conformity to a SIP
means that transportation activities will not produce new air quality
violations, worsen existing violations, or delay timely attainment of
the national ambient air quality standards.
    The conformity rule changes promulgated today result from the
experience that EPA, the Department of Transportation (DOT), and state
and local air and transportation officials have had with implementation
of the rule since it was first published in November of 1993. While
these changes clarify the rule and in some cases offer increased
flexibility, they will not result in any negative change in health and
environmental benefits.
    Today's rule gives state and local governments more authority in
selecting the performance measures used as tests of conformity and more
discretion when a transportation plan does not conform to a SIP. For
example, the rule allows motor vehicle emissions budgets in a submitted
SIP to be used to determine conformity instead of the ``build/no-
build'' test, and rural areas can choose among several conformity tests
to address the time period after that covered by the SIP.

EFFECTIVE DATE: September 15, 1997.

ADDRESSES: Materials relevant to this rulemaking are contained in
Docket No. A-96-05. The docket is located in room M-1500 Waterside Mall
(ground floor) at the Environmental Protection Agency, 401 M Street
SW., Washington, DC 20460. The docket may be inspected from 8 a.m. to
5:30 p.m., Monday through Friday, including all non-government
holidays. For information on electronic availability see Supplementary
Information.

FOR FURTHER INFORMATION CONTACT: Meg Patulski, Transportation and
Market Incentives Group, Regional and State Programs Division, U.S.
Environmental Protection Agency, 2565 Plymouth Road, Ann Arbor, MI
48105, patulski.meg@epamail.epa.gov. (313) 741-7842.

SUPPLEMENTARY INFORMATION:

Regulated Entities

    Entities potentially regulated by the conformity rule are those
which adopt, approve, or fund transportation plans, programs, or
projects under title 23 U.S.C. or title 49 U.S.C. Regulated categories
and entities include:

------------------------------------------------------------------------
                                                Examples of regulated
                 Category                             entities
------------------------------------------------------------------------
Local government..........................  Local transportation and air
                                             quality agencies.
State government..........................  State transportation and air
                                             quality agencies.
Federal government........................  Department of Transportation
                                             (Federal Highway
                                             Administration and Federal
                                             Transit Administration).
------------------------------------------------------------------------

    This table is not intended to be exhaustive, but rather provides a
guide for readers regarding entities likely to be affected by this
rule. This table lists the types of entities that EPA is now aware
could potentially be regulated by the conformity rule. Other types of
entities not listed in the table could also be regulated. To determine
whether your organization is regulated by this action, you should
carefully examine the applicability requirements in Sec. 93.102 of the
conformity rule. If you have questions regarding the applicability of
this action to a particular entity, consult the person listed in the
preceding FOR FURTHER INFORMATION CONTACT section.

Electronic Availability

    The final rule is also available electronically from the EPA
internet web site. Users are able to access and download files on their
first call using a personal computer according to the following
information:

Internet Web Sites

http://www.epa.gov/fedrgstr/EPA-AIR/
(either select desired date or use Search feature)
      Or
http://www.epa.gov/OMSWWW/
(look in What's New or under the Conformity file area)

The electronic version of this final rule should be available today on
any of the above-listed sites. Please note that due to differences
between the software used to develop the document and the software into
which the document may be downloaded, changes in format, page length,
etc. may occur.
    The contents of this preamble are listed in the following outline:

I. Background on Transportation Conformity
II. Replacement of Build/No-build Test With Submitted SIPs
III. Other Comments on Conformity Tests
IV. Conformity Tests for Areas That Are Not Required to Submit SIPs
V. Rural Nonattainment and Maintenance Areas
VI. Mismatch in SIP/Transportation Plan Timeframe
VII. Non-federal Projects
VIII. Deadline for Use of Network Models and Affected Areas
IX. Content of Network Modeling Requirements in Serious and Above
Ozone and CO Areas
X. Adding Non-Exempt Projects to the Plan/TIP Without Regional
Analysis
XI. Consequences of SIP Disapproval
XII. Traffic Signal Synchronization
XIII. Conformity SIPs
XIV. Hot-spot Tests
XV. TCM Flexibility
XVI. Conformity and the Proposed NAAQS Revisions
XVII. Minor Changes to the Rule
XVIII. Administrative Requirements

I. Background on Transportation Conformity

    Today's action amends the transportation conformity rule,
``Criteria and Procedures for Determining Conformity to State or
Federal Implementation Plans of Transportation Plans, Programs, and
Projects Funded or Approved Under Title 23 U.S.C. or the Federal
Transit Act'' (58 FR 62188, November 24, 1993). Required under section
176(c) of the Clean Air Act as amended in 1990, the transportation
conformity rule established the criteria and procedures by which the
Federal Highway Administration (FHWA), the Federal Transit
Administration (FTA), and metropolitan planning organizations (MPOs)
determine the conformity of federally funded or approved highway and
transit plans, programs, and projects to state air quality
implementation plans (SIPs). Conformity ensures that transportation
plans, programs, and projects do not produce new air quality
violations, worsen existing violations, or delay timely attainment of
national ambient air quality standards (NAAQS). According to the Clean
Air Act, federally supported activities must conform to the
implementation plan's

[[Page 43781]]

purpose of attaining and maintaining these standards.
    Since publication of the transportation conformity rule in November
1993, EPA, the Department of Transportation (DOT), and state and local
air and transportation officials have had considerable experience
implementing the criteria and procedures in the rule. This experience
has led to the streamlining, clarification, and new opportunities for
flexibility found in today's rule, which is the third of a series of
amendments to the transportation conformity rule. In each case, the
amendments were needed to clarify ambiguities, correct errors, or make
the conformity process more logical and feasible.
    The first set of amendments was published as an interim final rule
on February 8, 1995 (60 FR 7449), and was finalized on August 7, 1995
(60 FR 40098). The first set of amendments aligned the dates of
conformity lapses (i.e., halting conformity determinations for new
federally funded highway/transit projects) due to SIP failures with the
application of Clean Air Act highway sanctions for certain ozone areas
and all areas with disapproved SIPs with a protective finding (defined
below in section XI.).
    The second set of amendments was proposed on August 29, 1995 (60 FR
44790), and was finalized on November 14, 1995 (60 FR 57179). The
second set of amendments aligned the date of conformity lapses with the
date of application of Clean Air Act highway sanctions for any failure
to submit or submission of an incomplete control strategy SIP; extended
the grace period before which areas must determine conformity to a
submitted control strategy SIP; established a grace period before which
transportation plan and program conformity must be determined in newly
designated nonattainment areas; and corrected the nitrogen oxides
(NOX) provisions of the transportation conformity rule to be
consistent with the NOX requirements of the Clean Air Act
and previous commitments made by EPA.
    The second set of amendments also allowed any transportation
control measure (TCM) from an approved SIP to proceed during a
conformity lapse, although EPA stated that it did not intend to approve
SIPs containing TCMs that have not been coordinated through the
transportation planning process, as required by 23 CFR part 450 and 49
CFR part 613. The Clean Air Act and the Intermodal Surface
Transportation Efficiency Act require that an integrated
transportation/air quality planning process be used to identify
effective TCMs and ensure their funding sources.
    The Notice of Proposed Rulemaking for today's rule was published in
the Federal Register on July 9, 1996 (61 FR 36111). This proposal was
undertaken in response to several issues raised by conformity
implementers and other interested parties. EPA worked closely with
conformity stakeholders in developing the proposal, and had input from
the National Governors' Association (NGA), the Environmental Council of
States (ECOS), state DOTs, state environmental agencies, MPOs,
environmentalists, industry groups, other public interest groups, and
DOT. In 1995, meetings to discuss potential amendments to the
conformity rule were held by NGA and ECOS as well as the EPA. EPA
developed draft regulatory language in response and sought comment from
stakeholders.
    The proposal's comment period ended September 9, 1996. EPA held a
public hearing for this proposal on August 6, 1996. EPA received more
than 50 comments from a variety of interests, including MPOs, state and
local air quality agencies, state DOTs, NGA, and environmentalists.
Copies of comments in their entirety can be obtained from the docket
for this rule (see ADDRESSES). The docket also includes a complete
Response to Comments document for this rule.
    Since 1993, the transportation conformity rule has been included in
40 CFR part 51 and largely duplicated in 40 CFR part 93. In order to
streamline the CFR and eliminate this duplication, the only section of
today's conformity rule that remains in 40 CFR part 51 is Sec. 51.390,
which requires a conformity SIP revision. Part 51 is entitled,
``Requirements for Preparation, Adoption, and Submittal of
Implementation Plans.'' The remainder of the conformity rule is
included in 40 CFR part 93, which is entitled, ``Determining Conformity
of Federal Actions to State or Federal Implementation Plans.''

II. Replacement of Build/No-Build Test With Submitted SIPs

A. Description of Final Rule

    Today's action finalizes the proposal to eliminate the build/no-
build test and other emission reduction tests once a control strategy
SIP or maintenance plan has been submitted to EPA and EPA has had 45
days to review the SIP submission and the adequacy of its motor vehicle
emissions budget(s) for conformity purposes. This final rule also
includes regulatory text from the proposal's preamble which establishes
the minimum criteria that must be satisfied in order for EPA to find a
submitted motor vehicle emissions budget adequate for transportation
conformity purposes. EPA clarifies today that submitted SIPs must
already meet these minimum criteria in order to be approved; EPA is not
imposing any new requirements for submitted SIPs.
    EPA described the minimum adequacy criteria in the preamble to the
proposal (61 FR 36114, July 9, 1996), and they are outlined as follows.
In accordance with this final rule, an area's submitted SIP must be
endorsed by the Governor (or his/her designee) and subject to a public
hearing in order for EPA to find the submitted SIP adequate. Prior to
submitting the SIP, consultation between federal, state, and local
agencies must occur. SIP development must be documented and any
technical support information needed to review the adequacy of the SIP
must be submitted to EPA. In addition, any concerns stated by EPA must
be addressed before the SIP is submitted. The emissions budget(s) must
be clearly identified and precisely quantified. When considered with
point, area, and mobile sources, the emissions budget(s) must be
consistent with applicable requirements for reasonable further progress
(RFP), attainment, or maintenance, depending upon the particular SIP
submission. The SIP budget(s) must be consistent with the area's
emissions inventory for all sources and a clear relationship among the
budget(s), control measures and emissions inventory must be shown.
    In addition, submitted SIPs must explain and document any changes
to previously submitted motor vehicle emissions budgets and control
measures; impacts on point and area source emissions; any changes to
established safety margins; and reasons for the changes, including the
basis for any changes related to emission factors or estimates of
vehicle miles traveled (VMT). EPA is defining safety margin in this
final rule to be the amount by which the total projected emissions from
all sources of a given pollutant are less than the total emissions that
would satisfy the applicable Clean Air Act requirement for RFP,
attainment, or maintenance.
    EPA will interpret these adequacy criteria to mean that if a
submitted SIP's emissions budgets rely upon additional control measures
to demonstrate RFP, attainment, or maintenance, such new control
measures must be specified in the SIP submission. The submitted SIP
would need to quantify the emissions impacts of any new control
measures in its revised SIP, and at a minimum,

[[Page 43782]]

include commitments by appropriate agencies for adoption and
implementation schedules, in addition to draft regulations or other
relevant documents. These are minimum criteria for adequacy of
emissions budgets for conformity purposes; an approvable SIP must have
adopted and enforceable control measures.
    Prior to EPA determining the adequacy of a submitted SIP budget,
EPA will also review documentation from the state's public comment
hearing on the SIP submission and the state's responses to the public
comments received. This documentation is currently required to be
included in the SIP package when it is submitted to EPA for its review.
EPA will send a letter to the state documenting EPA's finding of
adequacy or inadequacy, including EPA's consideration of public
comment.
    The conformity adequacy review is separate from EPA's completeness
review of a submitted SIP for purposes of SIP processing. In addition,
EPA's 45-day adequacy review should not be used to prejudge EPA's
ultimate approval or disapproval of the SIP. As stated in the proposal,
EPA cannot ensure that a submitted SIP is consistent with RFP,
attainment, or maintenance until EPA has completed its formal review
process and the SIP has been approved or disapproved through notice-
and-comment rulemaking. Although the minimum criteria for adequacy
allow EPA to make a cursory review of the submitted motor vehicle
emissions budget for conformity purposes, EPA recognizes that other
elements must also be in the SIP for it to ultimately be approved.
Therefore, a budget that is found adequate in the 45-day review period
could later be disapproved when reviewed with the entire SIP
submission.
    EPA will find a submitted motor vehicle emissions budget inadequate
if the submitted budget does not meet the minimum criteria. However,
the criteria included in the conformity rule are not intended to be a
comprehensive definition of an adequate SIP for SIP approval purposes.
    EPA also clarifies that the 45-day adequacy review period begins
upon the receipt of the SIP submission in the EPA regional office.
    Areas that submit SIPs after the effective date of this final rule
will be able to use their SIP budget(s) within 45 days of submission or
sooner if EPA finds them adequate. Areas that submit SIPs prior to the
effective date of this final rule can use those SIPs according to the
requirements of Sec. 51.448(a)(2)/Sec. 93.128(a)(2) as amended on
November 14, 1995 (60 FR 57179). According to these sections, areas can
use submitted SIP budgets beginning 90 days after submission unless EPA
finds them inadequate; areas can use them earlier if EPA declares them
adequate.
    EPA's 90-day review period that is described in Sec. 51.448(a)(2)/
Sec. 93.128(a)(2) of the previous conformity rule may have used
different standards for adequacy than are being outlined in this final
rule, because under the previous rule the build/no-build test applied
in addition to the submitted budget. SIPs that EPA believed adequate
under that rule may not be adequate if they are the sole test of
conformity. As a result, EPA may use the adequacy criteria of this
final rule to re-examine SIPs that were submitted before this final
rule and have not yet been approved. EPA intends to complete this re-
examination within 45 days after the effective date of this final rule.
During this time, areas will continue using their SIPs that have been
submitted for more than 90 days; EPA's possible re-examination will not
delay or in any way interfere with areas determining conformity unless
EPA finds the SIP inadequate.

B. Rationale and Response to Comments

    Most commenters agreed that the emission reduction tests should not
be required once a SIP is submitted. The majority of commenters agreed
that compared to the budget test, the value of the build/no-build test
is limited. Commenters believed that the proposed flexibility would
streamline conformity and use state and local resources more
efficiently. Most commenters also supported the proposal's reduction of
the adequacy review period for a submitted SIP from 90 to 45 days.
    However, some commenters were concerned that submitted budgets may
not be able to fully satisfy the purpose of the emission reduction
tests, which is to ensure that annual emissions will be reduced and/or
that violations will not be created or worsened (see Clean Air Act
sections 176(c)(3)(A)(iii) and (c)(1)(B)). Specifically, some
commenters stated that the proposed EPA review period would not be
sufficient to ensure the adequacy of submitted budgets because the
proposal did not establish any objective criteria for adequacy in the
regulatory language, or provide an opportunity for public comment on
EPA's adequacy finding. Some argued that the absence of adequacy
criteria for submitted budgets could lead to the submission of inflated
budgets (not based on credible, quantifiable attainment demonstrations)
for the convenience of determining conformity. Commenters felt that
although these SIPs would ultimately not prove acceptable, they could
allow projects to proceed during EPA's rulemaking to disapprove the
SIP. This could also lead to delays in attainment. Another commenter
was concerned that the lack of objective criteria for adequacy in the
rule would make EPA more vulnerable to political pressure to approve
inadequate budgets.
    EPA agrees that if submitted budgets are to replace the build/no-
build test as the primary measure of conformity, the criteria by which
EPA will judge their adequacy must be clearly articulated in the rule.
EPA has done so in this final action, and these criteria are those
described in the preamble to the proposal. In addition, submitted SIPs
must already meet these criteria in order for EPA to ultimately approve
them. Since the criteria included in this final rule are the same as
those described in the proposal and thus subjected to public comment,
EPA does not believe a reproposal is necessary prior to adding the
criteria to the regulatory language.
    EPA also agrees that the public should be given the opportunity to
comment on the adequacy of a submitted SIP. Some commenters suggested
requiring public notice of submitted budgets and a 60-day period during
which the public could file objections and present arguments to EPA for
its consideration in its adequacy review. However, because the state
already holds a public hearing on the draft SIP before submitting it to
EPA, EPA believes the public has sufficient opportunity to comment at
the state level on the adequacy of the budgets contained in the SIP.
EPA believes the rule now addresses commenters' concerns by requiring
EPA to review and consider the compilation of public comment that the
state is already required to include with any SIP submission. EPA will
document its consideration of such comments in the letter to the state
indicating the adequacy of the submitted budget(s).
    Commenters also expressed concern that EPA is not even obligated to
determine adequacy, since a submitted budget can be used even if EPA
has not determined adequacy within the 45-day review period. However,
EPA is committed to helping ensure that conformity and future
transportation investment decisions are made using the best possible
SIPs, and EPA intends to review all submitted SIPs within the 45-day
period.
    Some commenters stated that EPA may not establish a motor vehicle
emissions budget as a legally enforceable obligation without following
the notice and comment procedures of the Administrative

[[Page 43783]]

Procedure Act (APA). EPA believes that it is appropriate not to provide
notice and comment for adequacy determinations for submitted SIPs,
since these determinations are only administrative reviews and not
substantive rules. When EPA reviews a SIP for completeness, EPA does
not perform a notice-and-comment rulemaking. EPA believes that
determining adequacy is more similar to completeness review than a SIP
approval action, in that adequacy determinations are merely
administrative applications of established criteria to emissions
budgets. For these reasons, EPA is not requiring notice and comment for
its 45-day adequacy review period. However, EPA believes the
commenters' concerns relating to public review under the APA are
addressed because EPA has established the criteria for determining
adequacy through this final rule, which has gone through APA notice and
comment procedures. In addition, EPA is ensuring that public comment on
adequacy of individual budgets is considered through review of comments
submitted to the state.
    In addition to specific criteria for adequacy, some commenters
wanted to limit the grandfathering of new projects found to conform on
the basis of a submitted SIP's budget. A ``grandfathered'' project can
proceed without further conformity determinations (see Sec. 93.102(c)
for more details). Transportation projects are currently grandfathered
after a National Environmental Policy Act (NEPA) document is approved
and a project-level conformity determination is made. In order for a
project-level conformity determination to occur, a conforming plan and
TIP must be in place at the time of the determination.
    Under the commenters' scenario, projects would only be
grandfathered when a project agreement authorizing federal funds
pursuant to 23 USC 110 or 49 USC 5309 has been executed. This would
grandfather projects later in the transportation planning process than
is currently the case. Changing the grandfathering in this manner would
make it more likely that local and state planners could halt a
project(s) if the SIP is ultimately disapproved. The commenters were
concerned that a submitted SIP's budget may not contain the necessary
emission reductions for demonstrating conformity in the future. If EPA
declared a budget adequate during the 45-day review period but later
disapproved it, commenters were concerned that an area may have
difficulty demonstrating conformity in the future if all the projects
planned according to that budget are grandfathered.
    EPA believes that current grandfathering requirements are
appropriate and should not be changed. EPA has always believed that
there should only be one point in the transportation planning process
at which a project-level conformity determination is necessary. This
maintains stability and efficiency in the transportation planning
process.
    Completion of the NEPA process is the step EPA has selected
historically for grandfathering transportation projects for several
reasons. Making a determination under NEPA is clearly an action to
support or approve an activity, and the Clean Air Act does not allow a
federal agency to take such an action without a conformity
determination. In addition, an air quality analysis is already required
by NEPA. To require this analysis again at a later date may create
redundancies in the transportation process and cause state and local
resources to be used less efficiently.
    EPA is partially addressing these stakeholder concerns by
maintaining adverse conformity consequences in the case of SIP
disapproval without a protective finding. As described in section XI.
of this preamble, today's final rule does not allow any new projects to
be added to the plan or TIP beginning 120 days after a SIP is
disapproved without a protective finding. In cases of a SIP disapproval
without a protective finding, areas would only be able to advance
projects in the first three years of the currently conforming plan and
TIP. Therefore, although EPA is not changing the grandfathering of
projects after a SIP is submitted, there are real consequences if a
submitted SIP is ultimately found to have emissions budgets that will
not result in reasonable further progress or attainment. In addition,
EPA believes that with the adequacy requirements added to the rule and
the review of submitted public comments, it is less likely that budgets
which EPA finds adequate will ultimately be disapproved.

III. Other Comments on Conformity Tests

A. Implementation of Budget Test: Submitted vs. Approved Budgets

    Some commenters stated that EPA should allow submitted SIP budgets
to override those in approved SIPs for years directly addressed by the
approved SIP. These commenters believed that newly submitted SIPs often
provide a more realistic picture of the future than approved SIPs. Some
believed that, unlike approved SIPs, newly submitted SIPs are more
accurate because they are based on an area's latest planning
assumptions.
    Although EPA acknowledges that using updated budgets may be
preferable, EPA does not believe that it is legal to allow a submitted
SIP to supersede an approved SIP for years addressed by the approved
SIP. As stated in the proposal, Clean Air Act section 176(c)
specifically requires conformity to be demonstrated to approved SIPs.
SIP revisions that EPA has approved under Clean Air Act section 110 are
enforceable and cannot be relieved by a submission, even if that
submission utilizes better data. Approved SIP budgets have also been
subject to full technical review and public comment and should not be
replaced by budgets that have not yet been fully analyzed and reviewed.
Some commenters suggested that EPA should institute another adequacy
review process (similar to that being finalized today for submitted
SIPs) which could ensure that submitted SIPs are consistent with
attainment or maintenance. However, this type of process does not
resolve the legal prohibition on overriding approved SIPs, and it would
not be possible to determine whether submitted SIPs are consistent with
attainment or maintenance without EPA's full public review and approval
process. Although submitted SIPs cannot override approved SIPs for
years addressed by the approved SIP, EPA did clarify in the proposal
and this final rule that submitted SIPs can be used for years later
than those addressed by an approved SIP.
    Others suggested that, if EPA could not allow submitted SIPs to
override approved SIPs, then EPA should require conformity
determinations to be done using the same models and inputs that were
used in the approved SIP. However, Clean Air Act section
176(c)(1)(B)(iii) requires that conformity determinations ``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.'' As stated in the preamble to the 1993
conformity rule (58 FR 62210), it is expected that over time conformity
determinations will deviate from the SIP's assumptions regarding VMT
growth, demographics, trip generation, etc. Conformity is intended to
ensure that a SIP's emission targets are achieved given the most recent
planning assumptions. If conformity cannot be demonstrated using the
most recent

[[Page 43784]]

planning assumptions, either the SIP or the transportation plan and TIP
must be adjusted.
    Even though an approved SIP can be changed if another SIP is
submitted and approved by EPA, some commenters believed that EPA's
review and approval of submitted SIPs would not occur in a timely
manner. The commenters urged EPA to conduct expedited review and
approval of submitted SIPs (e.g., 6- to 12-month timeframe), especially
those that are revisions of the currently approved SIP.
    EPA recognizes these stakeholder concerns and has already made
expedited approval processes, such as parallel processing, available to
states. In parallel processing, states can develop a draft SIP revision
with close EPA involvement. If all approvability issues are resolved
prior to submitting the SIP to EPA, the state and EPA then request
public comment on the SIP at the same time. If no adverse comment is
received, EPA then finalizes approval as soon as possible after formal
state adoption and submittal, as long as no substantive changes have
occurred and the package is still approvable. Parallel processing is
encouraged when SIP revisions are straightforward, especially when
assumptions are updated and new, significant control measures are
unnecessary. In addition to parallel processing, EPA can use direct
final rulemaking to approve SIPs more quickly in cases where EPA does
not expect adverse comment.

B. VMT Comparison as Substitute for Budget Test

    A few commenters recommended that areas be given the option to use
a VMT comparison test instead of the budget test, especially if data
sets and modeling used in the SIP are different than those used in the
plan and TIP. These commenters argued that the present budget test's
analytical inconsistencies could be eliminated if areas were allowed to
replace the budget test with a comparison of the projected vehicle
travel activity in the plan/TIP and that assumed in the SIP. If the
projected VMT in the plan/TIP is consistent with that in the SIP, the
commenters argued that Clean Air Act conformity requirements would be
met.
    In order to meet the ``VMT test,'' commenters said that areas would
have to demonstrate that: a) vehicle trips, VMT, and number of vehicles
projected in the proposed plan/TIP have not exceeded these projections
in the SIP; and, b) the transportation system in the proposed plan and
TIP, and vehicle speed distributions on that system, are found through
the consultation process to be in reasonable agreement with the system
and speed distributions assumed in the SIP. Commenters argued that this
idea is supported by Clean Air Act section 176(c)(2)(A) which says that
``emissions expected from the implementation of plans and programs are
consistent with estimates of emissions from motor vehicles and
necessary emissions reductions contained in the applicable
implementation plan * * *'' If an MPO's ``most recent population,
employment, travel and congestion estimates'' (section 176(c)(1)) do
not exceed estimates of these parameters in the SIP, the commenters
believe that the transportation community has fulfilled its Clean Air
Act requirements.
    EPA believes that this is not the correct legal interpretation of
Clean Air Act section 176(c)(2)(A), and consequently, a VMT-based test
is not a viable substitute for the budget test. As cited by the
commenters, section 176(c)(2)(A) emphasizes that the projected
emissions from the plan and TIP must be consistent with emissions
targets in the SIP. Emissions estimates depend on numerous factors
other than VMT, such as travel speed, fuels, inspection and maintenance
(I/M), or other technological factors, and thus emissions could
decrease even where VMT increases or vice-versa. Therefore, a VMT-based
test could possibly make it more difficult for some areas to
demonstrate conformity. For example, an area with high VMT growth could
have difficulty passing a VMT-based test, even though it might have a
cleaner fleet of vehicles resulting from electric vehicles or a
successful I/M program. For all of these reasons, EPA is not offering a
VMT-based test in this final rule.

IV. Conformity Tests for Areas That Are Not Required to Submit SIPs

A. Description of Final Rule

    Today's action finalizes many of the options that were proposed for
demonstrating conformity in areas that are not required to submit
control strategy SIPs. The July 9, 1996 proposal outlined three options
for determining conformity in these types of areas: (1) create a budget
through the SIP process and use the budget test; (2) create a default
budget based on clean data in areas that have achieved the standard but
have not submitted a maintenance plan; or (3) use either the build/no-
build or ``no-greater-than-1990'' emission reduction test. Today's
final rule keeps the first and third proposed options, while limiting
the second option.
    Areas that are not required to submit control strategy SIPs
include: marginal and below ozone nonattainment areas, not classified
carbon monoxide (CO) nonattainment areas, and moderate CO nonattainment
areas with a design value of 12.7 ppm or less. In addition, some
moderate and above ozone nonattainment areas that are meeting the NAAQS
are not required to submit control strategy SIPs. (See May 10, 1995,
memorandum from John S. Seitz, Director of the Office of Air Quality
Planning and Standards, to Regional Air Division Directors, entitled
``Reasonable Further Progress, Attainment Demonstrations, and Related
Requirements for Ozone Nonattainment Areas Meeting the Ozone National
Ambient Air Quality Standard'' for more information about this small
number of ozone areas.)
    Under the November 1993 transportation conformity rule, all areas
that are not required to submit control strategy SIPs had two options
for demonstrating conformity. They could choose between satisfying both
emission reduction tests (i.e., the build/no-build and less-than-1990
tests) or submitting a SIP and using the budget test. Areas that
decided to choose the latter option, under the former conformity rule,
were required to perform the build/no-build and less-than-1990 tests
until the submitted SIP was approved.
    According to this final rule, all areas that are not required to
submit control strategy SIPs can demonstrate conformity by using either
the build/no-build test or no-greater-than-1990 test (i.e., emissions
must be equal to or less than 1990 emissions); or, by submitting a SIP
through the regular SIP process and using the budget test 45 days after
submittal, provided EPA has not found the submitted SIP inadequate. The
SIP budget could be based on a modeled attainment demonstration or, for
areas with clean data (defined in the conformity rule as complete,
quality-assured monitoring data demonstrating attainment in accordance
with 40 CFR part 58), the SIP budget could be based on the motor
vehicle emissions in the most recent year of clean data.
    In addition to these options, moderate and above ozone
nonattainment areas which EPA declares through rulemaking to be ``clean
data areas'' under the May 10, 1995 policy could request that a budget
based on the level of motor vehicle emissions in the most recent year
of clean data be established through that EPA rulemaking process. See
the May 10, 1995 memorandum cited above for more information about
these types of areas.

[[Page 43785]]

B. Discussion of Comments and Rationale

1. Default Budgets for Clean Data Areas
    Most commenters supported the proposed options for demonstrating
conformity in areas that are not required to submit control strategy
SIPs. However, some questioned the enforceability of a ``default''
budget for clean data areas because such a budget would be created
through interagency consultation instead of the SIP process. Another
commenter argued that state air quality agencies should not be allowed
to create default budgets without EPA approval and public comment. The
commenter believed that this would be the equivalent of adopting an
element of the SIP, and it should be subject to the conformity rule's
public participation requirements and approval by EPA.
    After further consideration, EPA agrees that budgets must be
established through rulemaking; an area cannot adopt a default budget
without EPA review and public comment. As a result, if clean data areas
choose to create a budget, the SIP process must be used (through which
they could establish a budget based on clean data); or, if they are
subject to the May 10, 1995 memo, they could establish a budget through
the EPA rulemaking process described in the memo. Of course, clean data
areas could also choose to use the emission reduction test flexibility
already described above. Because both the SIP and rulemaking processes
provide for EPA review and an opportunity for public comment, EPA
believes that the commenters' concerns are addressed in the clean data
option of this final rule.
    EPA does not believe that areas choosing the rulemaking option will
have any additional administrative burden in submitting clean data
budgets for EPA review. Furthermore, since public comment is already a
part of the rulemaking process, additional time will not be needed for
gathering public input.
    EPA recognizes there are clean data areas for which EPA has already
completed rulemaking under the May 10, 1995, memorandum. If these areas
are not subject to a control strategy SIP, they have the choice of
using either the build/no-build or no-greater-than-1990 test, or the
budget test if they decide to create one through the SIP process.
Again, if such areas choose to submit a SIP budget, they have the
option of basing the budget on a demonstration of clean data (rather
than modeling) and the budget could be the motor vehicle emissions in
the most recent year of clean data.
    One commenter was concerned that, under the proposal, clean data
areas would not have an incentive to submit maintenance plans for
redesignation. EPA acknowledges the commenter's concern and believes
that limiting the default budget option in today's final rule addresses
this concern. However, EPA does believe that other significant
incentives already exist for areas with clean data to submit
maintenance plans.
    Another commenter argued that the July 9, 1996, proposal was flawed
because it would allow areas to adopt de facto budgets based on clean
years even if subsequent years have NAAQS violations (thus
demonstrating that budgets derived from clean data years are not
adequate to maintain the standard). EPA believes that the final rule
addresses this concern since any SIP budget would be established only
through the rulemaking or SIP process. If an approved emissions budget
is based on clean data and violations occur, EPA can issue a SIP call
or, if a SIP has not yet been approved, EPA can declare the submitted
budget inadequate during adequacy review. EPA also has the ability to
disapprove a submitted SIP based on clean data if violations occur
prior to approval.
2. Maintenance Areas
    A few commenters believed that the proposed options for areas that
are not required to submit control strategy SIPs should also be
available to these areas during the maintenance period.
    Since maintenance areas have already submitted SIP budgets and EPA
has approved those budgets, maintenance areas must use the motor
vehicle emissions budget(s) in their maintenance plans to demonstrate
conformity unless a subsequent budget demonstrating maintenance is
approved. As discussed in section III. of this preamble, ``Other
Comments on Conformity Tests,'' Clean Air Act section 176(c)
specifically requires conformity findings to be based on approved SIPs.
Maintenance plans that EPA has approved under Clean Air Act section 110
are enforceable and their budgets must be used for conformity.
3. Emission Reduction Test Flexibility in PM-10 and NO2
Nonattainment Areas
    One commenter requested that EPA remove the build/no-build test as
an option for demonstrating conformity in PM-10 (particles with an
aerodynamic diameter of less than or equal to a nominal 10 micrometers)
and NO2 (nitrogen dioxide) nonattainment areas that have not
submitted control strategy SIPs or maintenance plans. Section 93.119(c)
of the proposal, like the November 1993 final transportation conformity
rule, offered PM-10 and NO2 nonattainment areas the option
to use either the build/no-build test or no-greater-than-1990 test to
determine conformity, provided they have not submitted a control
strategy SIP or maintenance plan. The commenter believed that the
build/no-build test will not ensure that the frequency and severity of
existing violations will not be increased, as required by Clean Air Act
section 176(c)(1). Furthermore, commenters did not believe that the
same logic that was used in the November 1993 final rule could be used
to provide the build/no-build test option in ozone and CO nonattainment
areas that are not required to submit control strategy SIPs.
    Since the flexibility for PM-10 and NO2 nonattainment
areas was finalized in the November 24, 1993 conformity rule, the
deadline for commenting on this provision has passed, and EPA is not
obligated to respond to this comment. Nevertheless, EPA does believe
that it is appropriate to continue to offer the build/no-build test as
an option in PM-10 and NO2 nonattainment areas. By ensuring
that motor vehicle emissions are less than they would be if no new
transportation investments were made, the build/no-build test does
ensure that the frequency and severity of violations are not increased
as a result of new transportation investments. EPA believes that this
same rationale can be used to justify the build/no-build test option in
ozone and CO areas that are not required to submit control strategy
SIPs. In summary, EPA continues to believe that where no SIP has been
submitted, the build/no-build test is sufficient for areas to meet the
requirements of section 176(c)(1).

V. Rural Nonattainment and Maintenance Areas

A. Description of the Final Rule

    In today's action, EPA finalizes the flexibility proposed in
Sec. 93.119, with two minor clarifications. Rural nonattainment and
maintenance areas with submitted or approved control strategy SIPs or
maintenance plans will be allowed to choose among several tests for
demonstrating conformity for years after the time period addressed by
the SIP: (1) the budget test; (2) the emissions reduction tests
(``build/no-build test'' and/or one of the 1990 tests, depending on
what is required of the area's classification); or (3) air quality
modeling.

[[Page 43786]]

    In the proposal, EPA's third option was ``air quality dispersion
modeling,'' which was more specific than intended. The final rule's
language has been changed to allow an area to use the air quality
modeling technique it used in its SIP attainment or maintenance
demonstration, even if that technique is not dispersion modeling. For
example, some SIP attainment demonstrations (most commonly in PM-10
areas) are developed using rollback/rollforward techniques based on
emission inventories, and/or chemical mass balance modeling, pursuant
to EPA guidance. Where the SIP demonstration correctly used one of
these techniques, the conformity determination can use the same
technique. EPA will reject SIP budgets during the 45-day review period
if such non-dispersion modeling was used inappropriately.
    EPA also clarifies in the final rule that areas electing to use the
emissions reduction tests to demonstrate conformity for the outyears
must perform these tests even if the area has received a NOX
waiver.
    Generally, NOX waivers are findings by the EPA
Administrator under Clean Air Act sections 182(b) or 182(f) that
additional reductions of NOX would not contribute to
attainment of the ozone standard by the statutory deadline. Areas have
historically applied for NOX waivers to eliminate the
NOX emissions reduction requirement.
    When EPA proposed to allow rural ozone areas with attainment
demonstrations or maintenance plans to have the option of relying on
the NOX emissions reduction tests for the years not
addressed by these SIPs, EPA did not intend to allow these areas the
option of performing no NOX test at all. This would be the
result, however, if such areas could avoid meeting the substitute tests
by receiving NOX waivers. In the November 14, 1995,
conformity amendments (60 FR 57183), EPA stated that areas with
NOX budgets have to conform to these budgets even if they
were granted a NOX waiver. EPA emphasized that ``a
NOX waiver's demonstration that additional NOX
reductions would not contribute to attainment does not necessarily mean
that NOX increases would not affect an area's ability to
attain and maintain the standard. The purpose of a NOX
budget is to prevent NOX emissions from reaching levels that
would threaten attainment or maintenance of the ozone standard.''
    EPA is allowing rural ozone areas to substitute the emissions
reduction tests for the budget test as a means of demonstrating that
these areas are meeting the requirements of Clean Air Act section
176(c)(1) that plans, TIPs, and projects not cause or contribute to any
new violation, worsen existing violations, or delay attainment of the
NAAQS. Therefore, for the same reasons a NOX waiver cannot
exempt an area from the budget test, a NOX waiver cannot
exempt an area from the NOX emission reduction tests when
these tests are selected as a substitute for existing NOX
budgets. EPA believes that the clarification in the final rule is
consistent with EPA's original intentions and stakeholders'
understanding of the proposal, and therefore believes that a reproposal
is not necessary to incorporate this minor change.
    The choice of a test in rural areas will be determined through the
interagency consultation process and will reflect the consensus of the
state and local air and transportation agencies and the project
sponsor.

B. Rationale and Response to Comments

    Most commenters supported the proposal for increased flexibility in
rural areas. EPA changed the language for the air quality modeling
option because EPA agrees with the stakeholder who pointed out that
modeling techniques deemed adequate in certain areas for SIP attainment
demonstrations ought to be adequate in those areas for conformity
determinations as well. EPA originally referred to air quality
dispersion modeling because it is the technique generally required for
SIP demonstrations. Because some PM-10 areas appropriately use air
quality modeling that is not dispersion modeling, EPA has broadened its
language to allow use of these other techniques.
    One stakeholder commented that the proposal is illegal, because the
Clean Air Act does not provide for an exemption from the budget test
for rural areas. However, as explained in the proposal's preamble, EPA
believes that providing some flexibility for the years not addressed by
the SIP is consistent with the Clean Air Act. The Clean Air Act
requirement for consistency with the SIP's emissions reduction goals
can be construed to apply only for the years that an individual SIP
revision addresses, where there is another appropriate method of
demonstrating conformity as defined in Clean Air Act section 176(c)(1).
    In general, EPA believes that a SIP budget, even if it is not yet
approved by EPA, is a better measure of conformity than the build/no-
build test. For this reason, EPA requires most areas to continue
demonstrating conformity to the SIP emissions budgets even after the
timeframe of the SIP (see section VI., ``Mismatch in SIP/Transportation
Plan Timeframe,'' for more explanation). However, EPA believes it does
have the flexibility to allow conformity to be demonstrated using some
test other than the SIP budget for years not addressed by the SIP, if
that test is more appropriate.
    EPA believes that the reasons why the build/no-build test is less
desirable than the budget test for most areas do not apply in the
special circumstances of rural areas. The main critique of the build/
no-build test is that the difference in emissions that it predicts is
often small enough to be within the range of error of the models
themselves. EPA believes this will not be as problematic in rural
areas. Since there are fewer transportation projects and the
transportation network is less complex in rural areas, the build/no-
build test is more reliable. The test is better able to capture the
effects of new projects in such areas. Therefore, EPA believes it is
reasonable to allow the use of the build/no-build test as an option to
demonstrate conformity for the time period of the transportation plan
not covered by the SIP in rural areas.
    Several commenters provided ideas for additional flexibilities in
rural areas. One stakeholder suggested that areas should be able to use
the budget from any year of clean data when employing the budget test.
This suggestion is not being implemented today because SIP budgets must
be established through notice-and-comment rulemaking. As stated in
section IV. of this preamble, EPA believes that areas cannot adopt a
default budget based on clean data without EPA review and public
comment. See this section for more details on the options available for
areas with clean data.
    Another commenter suggested that areas be allowed to use
alternatives to regional modeling, such as ``subregional'' modeling or
``mesoscale analysis.'' EPA is not including that suggestion in this
section because specific modeling requirements do not apply to rural
areas; they only apply to urbanized areas with populations greater than
200,000. As a result, rural areas already have flexibility in modeling,
provided that their methods consider all regionally significant
projects in the nonattainment or maintenance area.
    Several stakeholders suggested that the rule explicitly require
state and local air agency concurrence for the selection of conformity
tests, rather than just consultation. EPA does intend that

[[Page 43787]]

agencies reach agreement on which test to use to demonstrate conformity
in a rural area. However, EPA is retaining the language of the
proposal, because of concerns that requiring concurrence would imply
that the existing conflict resolution process (by which state agencies
can elevate disputes to the governor) cannot be used. EPA believes that
the regulatory language adequately indicates that consensus should be
reached or disputes raised through the conflict resolution process.

VI. Mismatch in SIP/Transportation Plan Timeframe

A. Description of Final Rule

    This final rule retains the November 1993 conformity rule's
requirements (described in the proposal as option 1). Conformity must
continue to be demonstrated over a 20-year timeframe, and SIP budgets
continue to apply for conformity purposes for all future years until
superseded by other SIP revisions (except as provided in rural areas,
as described above).
    Although EPA is not changing the November 1993 conformity rule
requirements with respect to the mismatch issue, EPA's existing SIP
policy already does provide for some of the flexibility proposed in
option 3, which would have allowed a default emissions budget to be
established for years outside the maintenance plan's timeframe. Because
EPA is aware of the challenges posed by the differing timeframes of the
SIP and the transportation plan, EPA does allow SIPs to establish motor
vehicle emissions budgets for conformity purposes for years outside the
timeframe that the SIP normally addresses. For example, some areas are
developing maintenance plans that include motor vehicle emissions
budgets for conformity purposes for the years 2010 and 2015, even
though the initial demonstration of maintenance is only required to
address ten years. EPA's approval of these budgets is not an approval
of a full 20-year maintenance demonstration; these budgets are for
conformity purposes only and will be superseded when the second ten-
year maintenance plan is submitted.
    EPA will require areas to demonstrate that motor vehicle emissions
budgets for years outside the timeframe of the maintenance plan are
consistent with maintenance of air quality standards. EPA will not
permit areas to simply use the motor vehicle emissions in the year of
redesignation as a budget without considering growth in non-mobile
source emissions, which was a possibility discussed in the proposal
under option 3. However, EPA believes it has the flexibility to approve
budgets for years outside the usual maintenance plan timeframe for
conformity purposes based on less rigorous demonstrations than are
required for the Clean Air Act-mandated ten-year maintenance plan.
Whereas normally control measures must be fully adopted in order for
EPA to approve the SIP, EPA would be willing to approve conformity
budgets that were based in part on enforceable commitments to adopt
specific control measures in the future. Because these commitments
would be included in the approved SIP, they would be enforceable by all
parties, including the public. In addition, EPA would consider allowing
the motor vehicle emissions budgets in the last year of the ten-year
maintenance plan to be increased for future years provided offsetting
emissions reductions are adopted or committed to in the SIP.
    The ability to establish motor vehicle emissions budgets for
conformity purposes for years outside the normal timeframe of the SIP
is not specifically discussed in this final rule's regulatory text
because it is currently possible under EPA's existing SIP policy, and
therefore no regulatory changes are needed.

B. Rationale and Discussion of Comments

    EPA is finalizing option 1 (i.e., not changing conformity rule
requirements to address the mismatch in plan/SIP timeframes) for two
reasons. First, EPA believes there are important benefits associated
with this option, as commenters pointed out (discussed below). Second,
EPA believes there are adequate flexibilities under the existing
conformity rule and EPA SIP policy that will help areas address the
challenges of the timeframe mismatch in a manner that is more
supportive of air quality goals and prudent planning than any of the
other options proposed. The other options proposed included option 2,
which would have required emission reduction tests (``build/no-build
test'' and less-than-1990 test) for demonstrating conformity in years
not addressed by SIPs; and option 3, which would have allowed a default
motor vehicle emissions budget (such as the motor vehicle emissions in
the year of redesignation) to be used for the years outside the
maintenance plan's timeframe.
    Many commenters supported option 1 because they believe that
maintaining the SIP's emission targets for the timeframe of the
transportation plan is a central purpose of conformity and perhaps its
most important requirement. Commenters stated that because the
obligation to meet air quality standards persists indefinitely, the
obligation to meet the motor vehicle emissions budget should not
terminate after the attainment date or the last year of the maintenance
plan. According to some commenters, it is appropriate to analyze the
effects of transportation investments over a 20-year timeframe, because
it may in fact take decades for these effects to be fully realized.
They stated that it is better to use a long timeframe and make the
right choices at the outset than to pursue a path for several years and
then try to quickly overcome the adverse consequences of that path. One
commenter pointed out that demonstrating conformity to the SIP's budget
over the 20 years of the transportation plan is the best way to prepare
for the fact that the benefits of fleet turnover do decline over time.
    Some commenters preferred option 1 to the other options proposed
because option 1 requires emissions related to growth to be
specifically addressed and tradeoffs to be examined. According to these
commenters, the other options would not accomplish this, and the
conformity determinations that would result from these other options
would not have as much integrity because they would not be based on a
performance target with real meaning (i.e., a SIP budget that supports
reasonable further progress, attainment, or maintenance).
    Many other commenters supported option 3, which would have allowed
a default motor vehicle emissions budget for the years after the last
year of the maintenance plan. These commenters believe this option
would be less burdensome than the other options. They also believe that
SIP budgets may be unrealistic because they are not established with a
20-year horizon in mind, and therefore it is not necessarily
appropriate to require areas to conform to them indefinitely. Option 3
was broadly discussed in the preamble to the proposal and included
possibilities that ranged from allowing motor vehicle emissions to grow
to levels in the year of redesignation without consideration of growth
in non-mobile emissions, to allowing budgets to increase only if it is
demonstrated that the standards will be maintained when growth in
mobile, area, and stationary sources is considered. Several commenters
supported option 3 only if the motor vehicle emissions budgets were
based on a demonstration of maintenance that considered all emissions
sources.
    The approach that EPA is finalizing combines the benefits of option
1 with some of the flexibility contemplated by

[[Page 43788]]

option 3. EPA agrees with the commenters' reasons for supporting option
1. EPA is sympathetic to the concerns that prompted commenters to
advocate option 3, but EPA believes that the flexibility allowed under
existing SIP policy to establish reasonable budgets outside the
timeframe of the SIP is an effective means of addressing those concerns
without compromising the benefits of option 1. EPA is committed to
assisting areas with the challenges that arise when addressing long-
term emissions impacts. EPA also encourages a collaborative process
between local, state, and federal agencies in order to facilitate
acceptable solutions to these challenges under existing SIP policy.
    A few commenters preferred option 2 (emission reduction tests)
because in their specific areas they could pass the build/no-build test
but not the NOX budget test. However, some commenters
opposed option 2 because the emission reduction tests have significant
limitations and would not ensure that regional mobile source emissions
remain consistent with attainment or maintenance requirements. One
commenter stated that the build/no-build test is an imprecise
analytical approach that bears no direct relationship to the attainment
demonstration.
    EPA agrees that these arguments against option 2 are compelling.
Allowing areas to use emission reduction tests instead of SIP budgets
would be inconsistent with EPA's action described in section II. to
eliminate the emission reduction tests where SIP budgets have been
established. Overwhelming support has been expressed for this
elimination of the emission reduction tests in such cases, and this has
convinced EPA that option 2 is not a suitable solution for addressing
the mismatch of transportation plan and SIP timeframes. EPA is pursuing
the approach proposed in option 2 only in the limited case of rural
nonattainment and maintenance areas, for reasons specific to such areas
as explained in section V.

C. Response to Specific Comments

    Several commenters stated that EPA should allow areas to use any of
the three proposed options. A commenter suggested that the choice of
options would be decided by each area through its own interagency
consultation process. As explained above, EPA believes that the option
being finalized is the most appropriate. One commenter supported option
1 provided areas have more flexibility to account for future programs
that will affect emissions. Currently, areas cannot assume future
programs unless they are adopted or included in the SIP. EPA believes
that the approach being finalized today will allow the flexibility the
commenter is seeking, because it allows budgets established for
conformity purposes to be based on enforceable commitments in the SIP
rather than requiring fully adopted control measures, as needed for
approval as part of a control strategy SIP.
    One commenter suggested that the plan should be qualitatively
analyzed for the years beyond the timeframe of the SIP. EPA believes
this would not be consistent with the Clean Air Act's requirement for
the use of emissions estimates for determining conformity. In addition,
EPA believes that both the air quality and transportation planning
processes benefit from long-term quantitative analyses of
transportation plans. EPA believes that areas have sufficient
flexibility in analysis methods to develop a quantitative approach that
is both reasonable and useful.
    Some commenters suggested that conformity should not be required at
all in years beyond the timeframe of the SIP. Other commenters
suggested that conformity should not be required until there are tools
adequate to the task. EPA believes this is not consistent with the
Clean Air Act's requirement to demonstrate that the transportation plan
will not cause or worsen violations of air quality standards.
Conformity of a transportation plan cannot be determined unless all
years of the transportation plan are considered. EPA believes that
adequate analytical tools are currently available and are continually
being improved. All areas have great freedom to improve their own
analysis techniques, which EPA supports.
    One commenter suggested that the options proposed for rural
nonattainment and maintenance areas be provided for all areas as a way
of addressing the mismatch in transportation plan and SIP timeframes.
The options being provided to rural areas include a choice among the
SIP emissions budget, the emission reduction tests, or air quality
modeling. The emission reduction tests are not being pursued for all
areas as described in the discussion of option 2, above. The reasons
for using the emission reduction tests in rural areas, as described in
section V., are only applicable in rural areas and would not provide a
basis to use these tests in other areas. However, option 1 does give
areas the opportunity to use either the SIP emissions budget or
establish new budgets that are supported by air quality modeling.
    Some commenters stated that demonstrating consistency with the
motor vehicle emissions budget established for the attainment year or
the last year of the maintenance plan is not sufficient to demonstrate
that an activity will not cause or worsen air quality violations. These
commenters argue that it must be demonstrated that the motor vehicle
emissions budget is consistent with attainment or maintenance when the
most recent projections about non-mobile source emissions growth are
also considered. EPA does not believe that this is required by the
Clean Air Act. EPA believes that if motor vehicle emissions are less
than or equal to the most recent motor vehicle emissions budgets in the
SIP that was approved as meeting attainment or maintenance
requirements, then it can be stated that motor vehicles are not
``causing or contributing'' to violations, as required by the Clean Air
Act. It is not the role of the conformity requirements to provide
attainment or maintenance plans, but merely to prevent adverse impacts
on such demonstrations.
    However, EPA does recognize that consistency with the motor vehicle
emissions budgets for the transportation plan's 20-year timeframe does
not guarantee attainment or maintenance because of the possibility for
growth in non-mobile sources. This is one reason why EPA is not
finalizing a version of option 3 that would allow motor vehicle
emissions to increase above approved SIP budgets without considering
emissions from other sources.

VII. Non-Federal Projects

A. Description of Final Rule

    As was proposed, the final rule allows certain regionally
significant non-federal transportation projects to be adopted or
approved during a transportation plan/TIP conformity lapse, provided
the project was included in the regional emissions analysis supporting
the most recent transportation plan and TIP conformity determination.
Non-federal projects are projects which are funded or approved by a
recipient of federal funds designated under title 23 U.S.C. or the
Federal Transit Laws (49 U.S.C. Chapter 53) but which do not rely at
all on any FHWA/FTA funding or approvals.
    The final rule clarifies that only those non-federal projects from
the first three years of the most recent conforming plan and TIP (or
supporting regional emissions analysis) may proceed during a conformity
lapse. In the proposal, EPA had simply stated that non-federal projects
in the most recent conforming

[[Page 43789]]

plan and TIP's regional emissions analysis could proceed when a lapse
occurs.

B. Rationale for Clarification and Response to Comments

    Most commenters supported the proposal, and many said that it was
appropriate because the emissions impacts from affected non-federal
projects have already been considered and sufficient project reviews
have already occurred. However, some commenters expressed concern that
in their understanding the proposal would facilitate the exchanging of
funds between federal and non-federal projects during a conformity
lapse. Some even implied that there may be areas that would build large
numbers of non-federal projects by exchanging funds, and thereby, avoid
conformity consequences for an indefinite amount of time. There was
concern that because some TIPs cover more than three years, sometimes
even five or more years, a substantial number of non-federal projects
could be built during a conformity lapse. Some of these commenters even
believed that the proposal would allow areas to advance all non-federal
projects in the 20-year transportation planning horizon during a
conformity lapse, thus reducing or removing the incentive to develop
transportation plans and TIPs that actually do conform. EPA did not
intend this in the proposal, and as a result, EPA believes that a
regulatory clarification is necessary in this final rule.
    Although commenters suggested possible safeguards to protect
against such abuses, including limiting the number of non-federal
projects that could go forward during a lapse or restricting the
ability to exchange funds between federal and non-federal projects, EPA
believes that the final rule's clarification addresses these concerns.
    EPA did not intend that a non-federal project identified for any
year in the 20-year transportation planning horizon could proceed at
any time. This interpretation would be inconsistent with other
regulatory requirements and with the stated rationale for the proposed
non-federal project flexibility. Under DOT's metropolitan planning
requirements (23 CFR 450.332(c)), projects identified for funding in
the first three years of the plan and TIP are the only projects that
can proceed under any approved TIP. New TIPs are required every two
years, and projects from the outyears of an approved TIP cannot be
moved forward without a TIP amendment. Therefore, EPA believes that
allowing non-federal projects in the outyears of the TIP and plan to
advance at any time for conformity purposes is inconsistent with this
general regulatory context. In the proposal, EPA had intended that only
those projects already scheduled to begin in the timeframe of the first
three years of the TIP could proceed during a conformity lapse.
    There are several reasons why the final rule's clarification is
consistent with EPA's original intentions and rationale for providing
areas flexibility for non-federal projects. During the development of
the proposal, stakeholders who suggested the proposed non-federal
project flexibility argued that it was appropriate because future plans
and TIPs would have to consider the emissions from non-federal projects
and offset them as necessary. These projects would ultimately have to
be considered in the next TIP in the metropolitan planning process. In
addition, as EPA pointed out in the preamble to the proposal and as
many commenters argued, requiring non-federal projects to have been
included in the most recent conforming plan and TIP ensures that the
emissions consequences of the projects have been considered.
    Neither of these rationales would be consistent with allowing a
non-federal project from the outyears to proceed at any time. The
emissions analysis for the plan and TIP would no longer be valid if the
implementation dates of non-federal projects were altered. Allowing
non-federal projects from the outyears to be accelerated during a
conformity lapse so that a new conforming plan and TIP could be
substantially delayed would in effect be allowing the non-federal
projects to escape the scrutiny of the metropolitan planning process
which EPA had relied on in making the proposal. The final rule's
clarification ensures that the flexibility operates as originally
intended by EPA and conformity stakeholders. EPA believes this is fully
consistent with the original proposal and therefore does not require
any reproposal prior to proceeding with final action.

C. Governor Approval

    EPA requested comment on whether the governor should be required to
approve each non-federal project that would proceed during a conformity
lapse. EPA did not believe that it could propose such a change because
governor approval is not explicitly required by the Clean Air Act, and
it was unclear whether state and local officials should have the
authority to adopt or approve non-federal projects during a lapse. Due
to the comments received, EPA has decided not to require governor
approval in the final rule.
    EPA received many comments on this issue that strongly supported
the proposal to not require governor approval of non-federal projects
affected by the final rule. Many reasons were cited by commenters. Some
said that governor approval isn't necessary since the governor appoints
the directors of the state transportation and air agencies, and in some
cases, governors have even appointed the MPO as his/her designee for
air quality planning. Others emphasized that the conformity rule
already provides for involving the governor, when necessary, through
the conflict resolution process. Many argued that local non-federal
projects are usually time-sensitive and many local governments fund
these projects in order to expeditiously move them through the planning
process. In this case, requiring governor approval is unnecessary and
would impede rather than facilitate the process of non-federal project
implementation. Finally, some believed that it was not appropriate for
governors to have authority over approving local non-federal projects.
EPA agrees generally with commenters and believes that requiring
governor approval is not necessary. Therefore, EPA is not requiring
governor approval of non-federal projects during a conformity lapse.

D. Responses to Other Comments on Non-Federal Projects

    EPA received other comments on the proposed non-federal project
flexibility which did not result in changes to the proposal.
1. Comments Opposing Statutory Interpretation
    One commenter argued that any exemption for non-federal projects
would violate the statutory requirement that any such project only be
approved or funded if it either ``comes from a conforming plan and
program,'' or its emissions when considered with those of ``the
conforming transportation plans and programs within the nonattainment
area'' do not exceed the applicable emissions budgets. The commenter
argued that the present tense of the operative verbs in the statutory
language does not allow exemptions for projects that come from a plan
and program that no longer conform. The commenter also argued that this
exemption cannot be justified as a grandfathering mechanism because it
allegedly applies to projects that have not yet satisfied applicable
federal requirements. Finally, the commenter objected that the proposal
allows state DOTs to continue to build

[[Page 43790]]

projects with state funds during periods when the metropolitan
transportation plans fail to satisfy the Clean Air Act's requirements
for emission reductions, and therefore leads to a delay in attainment.
    EPA believes that it is appropriate to allow non-federally funded
projects that have previously satisfied conformity requirements to
proceed during a conformity lapse because the existence of a conforming
plan and TIP is not necessary to facilitate the implementation of such
projects. As to the commenter's concern about potential emissions
increases, any future plan and TIP will have to account for and offset
if necessary the emissions of any non-federal projects that are
implemented during a conformity lapse.
    EPA acknowledges that there is some tension with the present tense
statutory language concerning the existence of a conforming plan and
TIP. However, EPA believes that this is a proper case of grandfathering
projects that had been previously found to satisfy the applicable
federal conformity requirements. The only obligation imposed by the
conformity rule on non-federal projects is to account for project
emissions in a conforming plan and TIP. If this has been done, EPA
believes that it is appropriate to allow projects in the timeframe of
the first three years of the plan and TIP to proceed towards
implementation, so as not to interfere with the priorities of non-
federal entities funding such projects.
2. Changes in Implementation Date
    Another commenter said that it was unclear whether a non-federal
project could go forward during a lapse if the project's design concept
and scope had changed; or, if the project's implementation date had
changed in a manner that changed emissions in a milestone or analysis
year. Under the proposal and this final rule, a non-federal project
cannot go forward during a conformity lapse if its design concept and
scope has changed significantly. A non-federal project also cannot go
forward if its implementation date changes in a manner that changes the
emissions that the emissions analysis supporting the most recent
conforming plan and TIP projected for a given analysis year. In either
case, a new air quality analysis would be needed to ensure that the
project would still conform, and it would be inappropriate to allow
such projects to proceed based on the analysis in the most recent plan/
TIP. The final rule's clarification should reduce confusion on this
point.
3. Comments on Original Conformity Rule
    One commenter objected to the provisions of the original conformity
rule that do not require conformity determinations for non-federally
funded projects. The commenter included detailed statutory arguments
alleging that Clean Air Act section 176(c) on its face requires
conformity determinations for all transportation projects, and the
commenter also included citations to the legislative history supporting
these allegations. The commenter also argued that non-federal project
sponsors should provide a public process prior to determining that
emissions from non-federal projects are consistent with applicable
emissions budgets.
    EPA's proposal did not cover this aspect of the conformity rule,
which has been final since 1993. EPA did not intend to reopen the issue
of whether non-federal projects should undergo conformity
determinations when it proposed to allow certain non-federal projects
to proceed during a lapse. As EPA explained in the preamble to the 1993
conformity rule, Clean Air Act section 176(c)(2)(C) clearly
distinguishes non-federal projects from those projects required to
conduct a conformity determination, requiring only that non-federal
projects be considered in a regional emissions analysis prior to
adoption or approval. Non-federal projects are not covered in the
requirement to conduct a conformity determination in section 176(c)(1),
which applies only to actions of federal agencies and metropolitan
planning agencies. For these reasons, EPA is not responding in full to
comments submitted on this issue. For more explanation of EPA's
rationale for the provisions of the original conformity rule, see the
preamble to the final rule at 58 FR 62188, 62204 (Nov. 24, 1993).
Finally, since federal agencies do not approve non-federal projects,
such approvals are not subject to the requirements of the federal
Administrative Procedure Act. Non-federal project sponsors would have
to comply with any applicable public participation processes required
under state law.

VIII. Deadline for Use of Network Models and Affected Areas

A. Description of Final Rule

    Today's action finalizes the proposal to require serious CO and
serious, severe, and extreme ozone areas to use network models for
conformity determinations by January 1, 1997. In addition, as proposed,
these network modeling requirements are revised so that they only apply
to metropolitan planning areas with an urbanized area population over
200,000. EPA continues to believe that network modeling requirements
are most important for large urbanized areas, and therefore believes
that it is appropriate for the conformity rule to focus its specific
modeling requirements on them. See section IX.A. for a description of
the final rule's requirements for network models.
    As stated in the proposal and required under the original
conformity rule, whether or not an area is required to use a network
model, all areas must use the consultation process to select regional
models and assumptions, as required by Sec. 93.105(c).

B. Rationale and Discussion of Comments

    Most commenters supported the final rule's limiting of network
modeling requirements to serious and above areas with an urbanized
population over 200,000. Commenters agreed with EPA that network
modeling is not always appropriate in rural or urban areas with smaller
populations, and therefore, should not be required in these areas.
    One commenter suggested that all urban areas with a population
greater than 50,000 people should also be required to use network
models because these models are simple and inexpensive. However, the
commenter did not believe that the proposal would seriously weaken the
conformity process, since most of these smaller cities already use
network models for conformity analyses.
    As previously stated, EPA believes that network modeling
requirements are most important for large urbanized areas. As a result,
EPA is not changing the proposed population threshold. However, EPA
also notes that Sec. 93.122(c) of the conformity rule requires areas
that are already using network models to continue using them, even if
they are not serious or above areas or have a population less than
200,000. EPA and DOT will consider the specific technical needs of
smaller areas when developing future modeling guidance.
    A couple of commenters supported stratifying the network modeling
requirements by size of urban area. EPA believes that the final rule in
part addresses this concern by only requiring larger urbanized areas to
adhere to the network modeling requirements. However, EPA does not want
to create a complicated stratification system that would require
multiple sets of modeling requirements. Therefore, EPA did not

[[Page 43791]]

change the rule in response to this comment.
    As proposed, today's action also extends the deadline for
implementing the network modeling requirements from January 1, 1995, to
January 1, 1997. A few commenters suggested that MPOs that are not
meeting the rule's network modeling requirements should be put on a
timetable for compliance. Other commenters thought that extending the
deadline was unnecessary due to the ease of implementing such a network
model, especially since the majority of areas already have a network
model in place. They also felt that an extension would seriously weaken
the modeling regulation. Some commenters stated that the extension of
the deadline is obsolete, since the final rule would be published after
January 1, 1997.
    EPA acknowledges that the January 1, 1997, deadline has already
passed. The original conformity rule required that areas use network
models in conformity analyses by January 1, 1995, and when the proposal
was being developed, most areas had achieved the rule's network
modeling requirements by this deadline. However, as discussed in the
proposal, a few areas had not yet complied with the deadline, and EPA
believed that an extension until January 1, 1997, would be adequate to
address their difficulties.
    EPA did consider extending the deadline even further when it became
apparent that the final rule would not be effective before January 1,
1997. However, reproposal would have been necessary to significantly
extend the proposed January 1, 1997, deadline, and EPA believes it is
likely that the few areas in question will have adequate network models
developed before a reproposal could be finalized.
    For all of these reasons, EPA is retaining the January 1, 1997,
deadline. EPA agrees with the commenters that the majority of affected
areas are already using network models. EPA and DOT are currently
working with the two areas that have not yet met the network modeling
requirements so that they will overcome their unique circumstances and
meet the requirements in the future.

IX. Content of Network Modeling Requirements in Serious and Above Ozone
and CO Areas

A. Description of Final Rule

    In today's final rule, EPA is streamlining the conformity rule's
modeling requirements and committing to collaborate with DOT to develop
future modeling guidance. Specifically, EPA is eliminating several
modeling criteria from regulatory text while retaining those criteria
that establish minimum acceptable practice.
    The proposal requested comment on three options for addressing the
modeling criteria in the conformity rule. Option 1 proposed to
eliminate all of the 11 required attributes of network models in the
original November 24, 1993, final transportation conformity rule and
address the attributes only in guidance. Option 2 would have retained
all of the original modeling attributes. Option 3 proposed to
streamline the original requirements for network models and address the
eliminated attributes in guidance. Today's action finalizes option 3
with some minor modifications.
    The final rule includes six required elements for network modeling
in serious and above ozone and CO areas with an urbanized population
over 200,000. These elements include the five that were proposed as
option 3 (with minor wording changes), as well as the November 1993
conformity rule's requirement in Sec. 51.452(b)(1)(iv)/
Sec. 93.130(b)(1)(iv) for reasonable agreement between zone-to-zone
travel times used in trip distribution and the travel times resulting
from traffic assignment.
    Specifically, this final rule requires network-based models to be
validated against observed counts (peak and off-peak, if possible) for
a base year that is not more than ten years prior to the date of the
conformity determination. Model forecasts must be analyzed for
reasonableness and compared to historical trends and other factors, and
the results must be documented. Land use, population, employment, and
other network-based model assumptions must be documented and based on
the best available information. Scenarios of land development and use
must be consistent with the future transportation system alternatives
for which emissions are being estimated. The distribution of employment
and residences for different transportation options must be reasonable.
    A capacity-restrained traffic assignment methodology must be used,
and emissions estimates must be based on a methodology which
differentiates between peak and off-peak volumes and speeds, and which
uses speeds based on final assigned volumes. Zone-to-zone travel
impedances used to distribute trips between origin and destination
pairs must be in reasonable agreement with the travel times that are
estimated from final assigned traffic volumes. Where use of transit
currently is anticipated to be a significant factor in satisfying
transportation demand, these times should also be used for modeling
mode splits. Finally, network-based models must be reasonably sensitive
to changes in the time(s), cost(s), and other factors affecting travel
choices.
    EPA believes that the streamlined criteria and clarified rule
language will assist areas in implementing the rule's network modeling
provisions. The final rule does not create any new network modeling
requirements for large, urbanized serious and above ozone and CO areas.
    As stated in the proposal, EPA and DOT will develop modeling
guidance in the future to address some of the modeling requirements
that were eliminated from the final rule and to foster the exchange of
information on current and future modeling improvements. As discussed
later in this section, EPA and DOT are committed to an open stakeholder
process about modeling procedures that will begin shortly after the
rule becomes effective.

B. Rationale and Discussion of Comments: Selected Option

    There were commenters who supported each of the three proposed
options for the content of the network modeling requirements. Some
supported option 1 because they believed that eliminating all modeling
attributes would simplify the conformity rule and create maximum
flexibility for areas. Other commenters argued strongly for option 2,
which would have retained all 11 modeling attributes from the original
rule. According to one commenter, removing all of the modeling
attributes from the rule would have detrimental effects on the entire
conformity process. Finally, many commenters from the transportation
and environmental communities supported option 3, which proposed to
streamline the modeling requirements without fully eliminating them.
These commenters believed that having some baseline modeling criteria
in the rule ensures national consistency of network models while
streamlining the rule to allow for flexibility at the state and local
levels.
    As previously stated, this final rule streamlines the original
conformity rule's network modeling criteria by eliminating some
criteria and clarifying the rule's language. EPA is retaining some
modeling requirements in this final rule because EPA agrees with
commenters that minimum modeling standards are an important component
of the conformity process. Many commenters believed that all or some of
the original modeling criteria should be retained in the final rule,
because without them, modeling practice would

[[Page 43792]]

become highly variable across the country. They also thought that
eliminating all criteria would undermine the integrity, reliability,
and credibility of the process for assessing the expected impacts of
transportation investments on travel demand, travel behavior, and
estimates of future vehicle miles traveled (VMT) and emissions. Others
believed that having modeling criteria in the conformity rule has
spurred the funding and development of state and local transportation
model improvements. Finally, some pointed out that sound network models
are needed for other processes besides conformity, such as SIP
development, and therefore should be retained.
    Other commenters were concerned that lawsuits would increase if all
of the modeling attributes were eliminated, due to the inconsistency of
requirements across the country. According to commenters, the outcomes
of these suits would be hard to predict and money would be wasted in
the adversarial process.
    EPA agrees with these comments and believes that the final rule
addresses them. EPA also agrees that nationally consistent and
enforceable minimum standards are central to the integrity of the
conformity process. Minimum standards clarify the expectations of all
agencies involved in the conformity process and thus ensure some equity
among all areas.
    One commenter argued that EPA cannot eliminate all of the modeling
attributes because they are a regulatory requirement which cannot be
substituted with unspecified guidance that is developed outside of the
rulemaking process. EPA agrees with this comment and is addressing it
by retaining minimum standards in this final rule.
    Although some commenters supported option 1, EPA does not believe
that eliminating the modeling requirements is necessary to achieve the
objectives of these particular commenters. Some supported option 1
because eliminating all modeling criteria would allow areas to tailor
their network models to satisfy their current modeling and air quality
planning needs. According to one commenter, this option would
distribute resources and technical expertise appropriately in state and
local agencies. Commenters also believed that under option 1 areas
would be able to do sound quantitative analysis while having the
flexibility to accommodate modeling improvements and demographic
changes in their area. A couple of commenters suggested states should
have the authority to determine network model attributes on an area-by-
area basis, and one approach for this is to allow state-level approval
of an area's model subject to the interagency consultation process.
    EPA believes that areas have the flexibility to appropriately
tailor their models and distribute their resources under option 3 as
well as option 1. The conformity rule's modeling requirements define
minimum acceptable practice, and beyond this, areas have flexibility to
determine appropriate modeling practices and accommodate modeling
improvements through interagency consultation. EPA does not believe
that areas should be able to use models that do not meet minimum
standards of acceptable professional practice, for the reasons
described in this section.
    One commenter stated that the criteria in options 2 and 3 are
accounted for in some way in existing practice, and that requiring them
does not advance the state of the practice and may hinder it if future
developments lead to improved, but different, methodologies. Another
commenter suggested that by eliminating all modeling criteria, EPA and
DOT could incorporate future modeling improvements by revising the
guidance rather than having to go through the difficult and time-
consuming process of revising the rule. Others believed option 1 would
give agencies across the country access to technical changes and
expertise which may not be available to them on a case-by-case basis,
and may provide a better way of communicating updates and improvements
in network modeling procedures.
    EPA does not believe that establishing baseline modeling criteria,
as is being done in this final rule, will inhibit the adoption of
future modeling improvements. EPA agrees that future modeling guidance
should provide information to state and local agencies about modeling
updates, and EPA and DOT are committed to working with stakeholders to
exchange ideas in the guidance development process. However, EPA does
not believe it is necessary to eliminate the rule's modeling
requirements in order to issue future modeling guidance. As general
modeling practices improve, EPA and DOT will make periodic updates in
the form of non-enforceable modeling guidance, rather than future
amendments to the conformity rule.
    An area that has not yet implemented the currently required model
improvements supported option 1 because the area believed option 1
would provide flexibility and make a conformity lapse for this area
less likely. EPA believes that it would be inappropriate to eliminate
all of the modeling criteria just because a few areas are having
temporary difficulty achieving them. This stakeholder concern was also
raised in the context of extending the deadline for implementing
network modeling requirements. EPA considered the merits of this
comment, and as outlined above, decided that a reproposal to extend the
deadline could not be completed in time to provide relief to the few
affected areas. As previously mentioned, EPA and DOT are assisting the
two areas without adequate network models to achieve the minimum
standards in this rule.
    EPA believes that option 3 also addresses the concerns of the
commenters who supported option 2. These commenters seemed most
concerned with whether any modeling requirements would be retained in
the rule; option 1 would have eliminated all of the rule's network
modeling requirements. Many of the commenters who supported option 2
also supported option 3, provided there were modifications for some of
the language in option 3. EPA believes that the changes made to option
3, which are discussed below, make the final rule's language more
streamlined, clear, and useful than the 1993 conformity rule language
proposed for retention in option 2.
    A few commenters who supported option 3 also thought that areas
should not be required to use network modeling improvements in the
conformity process prior to their application in the SIP process. The
commenters believed this would remedy problems associated with
inconsistencies between the models used in conformity analysis and
those used in SIP development. EPA recognizes the commenters' concerns
about the implementation difficulties that may occur as a result of
model improvements. However, Clean Air Act section 176(c)(1)(B)(iii)
requires conformity determinations to ``be based on the most recent
estimates of emissions.'' EPA believes that areas must use the most
current tools available at the time of the conformity determination, in
accordance with the Clean Air Act. Using the best models and
assumptions will also produce the best emissions estimates on which
areas will base decisions regarding transportation and air quality. EPA
also notes that areas already have the ability to use the consultation
process to coordinate the introduction of transportation modeling
improvements into their planning processes. For these reasons, EPA is
not finalizing the commenters' suggestion.

[[Page 43793]]

C. Future Modeling Guidance and Response to Comments

    As stated in the proposal, EPA and DOT will develop modeling
guidance in the future. This guidance will address some of the modeling
requirements that were eliminated from the final rule; provide guidance
on implementing modeling requirements; and facilitate the exchange of
information on advancements in modeling. EPA and DOT are committed to
working with stakeholders in the development of the guidance, an idea
which was supported by many commenters. This process will begin soon
after this rule becomes effective, and will include stakeholder
participation in workshops for developing the guidance. In addition,
EPA and DOT will make drafts available for stakeholder comments. This
joint federal, state, and local effort will bring together the
expertise to assure national consistency and meaningful emissions
results in conformity analyses.
    Some commenters were concerned that the guidance would be mandatory
and that future guidance updates would be difficult to implement if it
were mandatory. Today, EPA clarifies that the guidance will not be an
enforceable requirement, although EPA and DOT encourage use of future
guidance on a voluntary basis as deemed appropriate by affected state
and local agencies. There is also no specific date by which future
modeling guidance must be used, or by which models are required to be
improved in accordance with future guidance, since the use of future
guidance is not an enforceable requirement. Areas will decide upon how
to implement modeling guidance using the interagency consultation
process.
    Another commenter said that each MPO should have the responsibility
to demonstrate the adequacy of their model through documentation, and
such documentation should be included as an appendix to the area's
conformity package. EPA agrees with this comment and encourages MPOs to
submit such documentation with their conformity determinations.

D. Rationale and Discussion of Comments: Specific Criteria

    As discussed above, this final rule specifies six requirements for
network models for serious and above ozone and CO areas. These replace
the 11 that were required by the November 1993 conformity rule. This
final rule includes the five requirements that were proposed as option
3, as well as a requirement from the November 1993 conformity rule that
was not originally proposed as part of option 3 (but was included in
proposed option 2, which included all requirements of the 1993 rule).
Several minor changes were made to the wording proposed in option 3 in
order to respond to comments, reduce ambiguity, and streamline the
text.
    EPA proposed to require network-based models to be validated
against peak and off-peak ground counts for a base year that is not
more than ten years prior to the date of the conformity determination.
The final rule requires validation against ``observed'' counts rather
than ``ground'' counts because the term ``ground'' counts sometimes
implies automobile counts only. In fact, models should be validated
against counts for all modes, including transit, bicycle, and
pedestrian. EPA believes that because ``observed'' counts is a more
general term, it more appropriately conveys the intent of the proposed
requirement.
    EPA has also qualified the proposed requirement for validation
against peak and off-peak counts so that validation against both peak
and off-peak counts is only required where it is possible. The November
1993 conformity rule simply required validation against ground counts;
there was no reference to peak and off-peak. When EPA proposed option
3, it did not intend to impose any new or more stringent network
modeling requirements. Since the time of the proposal EPA has become
aware that not all areas collect peak and off-peak counts. As a result,
although EPA continues to believe that validation against peak and off-
peak counts is preferable, the rule only requires it where it is
already possible given available data.
    A commenter suggested that the conformity rule should require areas
to validate their models for a second year at least three years before
or after the base year whenever possible. The commenter also suggested
that the rule require validation against peak and off-peak travel
demand, traffic volume, speed, and mode share data for household and
commercial travel. EPA did not incorporate these suggestions in the
conformity rule because the modeling requirements are only intended to
outline minimum practice, and in addition, EPA intends for these
amendments to streamline the existing rule. The EPA/DOT modeling
guidance will have further discussion about best practices and other
advances in validation techniques, and EPA believes that this will be a
better forum to address the commenter's ideas.
    This final rule adds to the proposed validation requirement a
sentence specifying that model forecasts must be analyzed for
reasonableness and compared to historical trends and other factors, and
that the results must be documented. This sentence was added for
several reasons. First, a commenter suggested that the conformity rule
should require model forecasts to be compared to documented historical
trends in travel behavior, such as changes in per capita vehicle trips
and VMT, trip length, mode shares, and time-of-day-travel, and require
significant differences between trends and forecasts to be explained.
EPA agrees that this is minimum acceptable practice and has added
language to the conformity rule accordingly. The language that is
included in the final rule is more general than that suggested by the
commenter, and EPA plans for the EPA/DOT modeling guidance to address
the issue in more detail. EPA also added this language because it
better reflects what EPA intended when it proposed that network-based
modeling inputs (such as land use, population, and employment) be
appropriate to the validation base year. This language is consistent
with the proposal on this issue and does not require reproposal prior
to final action.
    The second network modeling requirement in the final rule requires
land use, population, employment, and other network-based model
assumptions to be documented and based on the best available
information. The proposal's requirement for these assumptions to be
``appropriate to the validation base year'' has been eliminated in
favor of the new language described above that requires reasonableness
checks as part of validation. A commenter suggested that the proposed
requirement be expanded to refer not only to land use, population, and
employment assumptions, but also demographic and spatial attribute
assumptions. EPA believes that the final rule's reference to ``other
network-based modeling inputs'' is sufficiently inclusive, and
specificity such as the commenter suggests is more appropriate to the
EPA/DOT modeling guidance.
    The final rule's third network modeling requirement states that
scenarios of land development and use must be consistent with the
future transportation system alternatives for which emissions are being
estimated. This is substantially similar to the language proposed as
the fourth modeling requirement in option 3, with minor wording
adjustments for the sake of clarity. The final rule also includes a
sentence stating that the distribution of employment and residences for
different transportation options must be reasonable. This statement is
intended

[[Page 43794]]

as further clarification of what was intended by the original proposed
language. Appropriate consideration must be given to how major
anticipated transportation system improvements might influence
development and, in turn, how that might affect the forecasted
distribution of population and employment used to estimate travel and
emissions.
    A commenter suggested that instead of the proposed language, EPA
should require that areas make reasonable adjustments to land use
assumptions between scenarios to account for effects of changes in
accessibility on the likely timing and pattern of development, using
the best methods available. EPA does not believe it is appropriate for
the conformity rule to specifically require the use of the ``best''
methods, because cutting-edge practices may not be reasonably available
at the same time in all areas subject to conformity's network modeling
requirements. With this exception, EPA believes that the commenter's
suggestion is basically a restatement of the language that is being
finalized.
    The final rule's fourth network modeling requirement states that a
capacity-sensitive assignment methodology must be used. In addition,
emission estimates must be based on a methodology which differentiates
between peak and off-peak link volumes and speeds and uses speeds based
on final assigned volumes. This additional language clarifies the
proposed requirement that ``peak and off-peak travel demand and travel
times must be provided,'' which did not indicate which step in the
modeling process was being referred to. EPA in fact simply intends that
emissions be calculated on the basis of peak and off-peak speeds
separately and applied to peak and off-peak final assigned volumes,
regardless of whether these assigned volumes are based on peak and off-
peak modeling or are modeled on a 24-hour basis.
    The final rule's fifth network modeling requirement is based on
Sec. 51.452(b)(1)(iv)/Sec. 93.130(b)(1)(iv) of the November 1993
conformity rule, which requires feedback of travel times resulting from
traffic assignment to travel times used in trip distribution. Although
this requirement was not proposed as part of option 3, EPA received
comments based on proposed option 2 that this requirement of the
original rule should be retained. Commenters pointed out that this type
of consistency in the evaluation of travel time is almost universally
recognized to be scientifically valid. A commenter stated that not
requiring feedback would allow analyses to be manipulated to produce
desired results. Another commenter stated that most MPOs have already
implemented full feedback, and it is easy to perform and more accurate
than partial feedback. Commenters submitted technical reports and
papers to the docket in order to document their claims that full
feedback is recognized to be a necessary and sound modeling
improvement.
    EPA agrees with commenters that there is clear theoretical
justification for feedback between traffic assignment and trip
distribution, and that feedback may be essential to accurate forecasts
when congestion exists. In addition, EPA agrees that full feedback is
already widely available and used. As a result, EPA believes it is
appropriate to retain the feedback requirement.
    The regulatory language has been slightly modified from the
November 1993 rule to read that zone-to-zone travel impedances used in
trip distribution must be in reasonable agreement with travel times
that are estimated from final assigned traffic volumes. The language
now refers to ``impedances'' rather than ``travel times'' because trip
distribution impedances may reflect more than just vehicle travel time
(e.g., cost, travel times by other modes, etc.). The language refers to
travel times ``estimated from final assigned traffic volumes'' rather
than travel times ``which result from'' traffic assignment in order to
reflect the fact that speeds should be estimated by post-processing
assigned volumes.
    The final rule's sixth and final network modeling requirement is
for network-based models to be reasonably sensitive to changes in the
time(s), cost(s), and other factors affecting travel choices. EPA's
proposed option 3 would have required models to be reasonably sensitive
to trip-making changes due to changes in the cost, travel time,
capacity, and quality of all travel choices, if the necessary
information is available. EPA has eliminated the reference to ``trip-
making changes'' because EPA received comments indicating that this
implies a requirement for trip generation to be dependent on
accessibility. This is not what EPA intended. The November 1993
conformity rule strongly encouraged a dependence of trip generation on
the accessibility of destinations, but it was not specifically
required. EPA continues to believe that such a trip generation
requirement is not widely available, minimum practice. In addition to
deleting ``trip-making changes,'' EPA made other modifications to the
proposed requirement in order to streamline the language. By making the
language more general, EPA believes that the qualification ``if the
necessary information is available'' is no longer necessary. EPA has
therefore eliminated this language.
    EPA received comment that Sec. 51.452(b)(1)(v)/Sec. 93.130(b)(1)(v)
of the November 1993 conformity rule should be retained in addition to
the other paragraphs proposed as option 3. Section 51.452(b)(1)(v)/
Sec. 93.130(b)(1)(v) of the November 1993 conformity rule required
free-flow speeds on network links to be based on empirical
observations. EPA is not including this requirement in the final rule
because it has been widely misinterpreted, and because issues relating
to the use of speeds in network models are complex enough that they are
best handled in modeling guidance, where they can be fully discussed.
The November 1993 requirement was read by some to require significant
data collection efforts. In fact, EPA had simply intended that
available empirical information be used instead of posted speed limits.
In addition to creating this misinterpretation, the original language
was not clear about which step of the modeling process it referred to,
and whether it was directed at input assumptions or outputs.
    EPA believes that this issue warrants a full discussion in the EPA/
DOT modeling guidance, and that the original regulatory requirement
regarding free-flow speeds should be eliminated from the streamlined
rule in order to avoid confusion. However, EPA and DOT would like to
emphasize that input network speed assumptions used in model
application must be consistent with speed assumptions used in model
development and calibration, and that these assumptions and calibration
techniques should be documented. EPA and DOT recognize that free-flow
impedance inputs into traffic assignment may not reflect empirically
observed free-flow speeds, because these input impedances may reflect
considerations that affect travel behavior other than travel time, such
as driver preferences for using specific classes of facilities. If
free-flow impedance inputs used in traffic assignment deviate
significantly from observed free-flow speeds, the documentation should
include a discussion of the differences and rationale for adjustments
made.
    In addition, since emissions estimates are extremely sensitive to
vehicle speed, EPA and DOT recommend that speeds be estimated in a
separate step after traffic assignment (also known as ``post-
processing''), using refined speed-

[[Page 43795]]

 volume relationships and final assigned traffic volumes. Post-
processed speeds estimated in the validation year should be compared
with speeds empirically observed during the peak and off-peak periods.
These comparisons may be made for typical facilities, for example, by
facility class/area type category. Based on these comparisons, speed-
volume relationships used for speed post-processing should be adjusted
to obtain reasonable agreement with observed speeds. Regardless of the
specific analytical technique, every effort must be made to ensure that
speed estimates are credible and based on a reproducible and logical
analytical procedure.

X. Adding Non-Exempt Projects to the Plan/TIP Without Regional Analysis

A. Description of Final Rule

    In today's final rule, EPA is not finalizing the flexibility
proposed in Sec. 93.122(b)(4), which would have allowed projects to be
added to the plan and TIP based on an alternate emissions analysis that
does not use network modeling (for areas that are required to use
network models, i.e., serious and above areas with an urbanized
population over 200,000). This final rule retains the 1993 conformity
rule requirement that every plan/TIP amendment that involves regionally
significant, non-exempt projects requires the same level of regional
emissions analysis. For the purposes of this discussion, a non-exempt
project is any transportation project other than those listed in
Sec. 93.126, ``Exempt projects,'' and Sec. 93.127, ``Projects exempt
from regional emissions analysis.''
    Areas that are not serious or above or do not have an urbanized
population over 200,000 are not affected by the proposal or this change
to the proposal, because they are not subject to requirements for
network models.

B. Rationale

    Based on stakeholder comments received, EPA has determined that the
flexibility to add projects without a regional emissions analysis would
have to be accompanied by safeguards or limitations that were not
proposed. EPA believes that the restrictions that would have to be
imposed on the flexibility would outweigh its benefits.
    EPA agrees with a commenter who pointed out that regulatory
requirements that govern how satisfaction of a conformity test is
demonstrated cannot be removed and replaced with unspecified guidance
that is not subject to notice and comment. EPA believes that the
commenter is correct in asserting that guidelines for how the alternate
emissions analysis would have to be performed would have to be included
in regulatory language, if the flexibility were to be finalized. Such
additional regulatory language would require reproposal because it is a
significant departure from what was originally proposed; EPA did not
propose any specific guidelines or limitations for this flexibility in
either the preamble or regulatory language of the July 9, 1996,
proposal.
    Other commenters expressed serious concerns that the flexibility to
add projects without analysis could undermine the coordinated planning
process and achievement of air quality objectives unless some
safeguards are included. Suggestions for limitations and safeguards
included adding minimum criteria for alternate analysis methodology in
the rule; limiting the flexibility to projects which are unlikely to
cause major long-term changes in travel and development patterns;
limiting the flexibility to a certain number of projects per planning
cycle; or requiring that the emissions from the existing plan and TIP
be below a minimum threshold of the applicable emissions budget.
Commenters were also concerned that safeguards needed to be applied
consistently throughout the country. Including such safeguards would
require reproposal, and could result in additional rule complexity that
would hamper use of the proposed flexibility.
    Because EPA believes it is legally compelled to include minimum
guidelines for alternate emissions analysis in the regulatory text,
EPA's choice was to either repropose regulatory guidelines and
safeguards or eliminate the proposed flexibility. EPA is choosing the
latter in today's final rule because the few alternate methodologies
suggested by commenters were not sufficient to provide a basis for EPA
to propose general regulatory guidelines. In addition, EPA believes
that additional regulatory text would outweigh the benefits of the
flexibility.
    The few methodologies proposed by stakeholders were not sufficient
to form the basis of nationally applicable, minimum guidelines for
alternate emissions analysis. When EPA proposed the flexibility, it was
seeking a procedure that would yield similar results as a full-scale
regional analysis but with less effort. However, the methodologies
suggested by commenters were sketch planning techniques, which are
ancillary to but not substitutes for network modeling. While sketch
planning techniques may be appropriate for certain projects in certain
circumstances, the commenters did not suggest guidelines that would
delineate when sketch planning techniques may be an adequate
approximation or how these techniques could be replicated nationally.
    Based on comments received during the development of the proposal
and during the comment period on the proposal itself, EPA and DOT
believe that regulatory constraints on the proposed flexibility would
defeat the flexibility's purpose. Many commenters did not believe EPA
could or should develop alternate analysis techniques that would apply
nationally, because the value of the flexibility would be its
application on a case-by-case basis. In addition, many stakeholders
want the regulatory text to be streamlined and procedural modeling
guidelines to be minimized.
    EPA and DOT also believe that the possible benefits of the proposed
flexibility do not warrant the complication of a new set of modeling
guidelines. Commenters have indicated that the proposed flexibility
would not have a large impact on day-to-day implementation of the
conformity rule. Many commenters stated that the flexibility would be
used infrequently, or only in limited circumstances. Some commenters
believe that a full-scale regional analysis is just as easy as using an
alternate sketch planning method. For example, a commenter indicated
that adding a project and running the regional model again is not time-
consuming once the network for the plan has already been coded. EPA and
DOT believe the time and effort spent in developing an alternate
procedure and getting agreement from all involved agencies seems
greater than that involved in running the regional model.

C. Pilot Program

    Although EPA did not grant the general analysis flexibility in
today's final rule, EPA and DOT remain willing to consider alternate
procedures on a case-by-case basis for determining the impact of
transportation projects, since a substitute may prove to be more
expeditious and less costly in certain circumstances than a network-
based analysis. Those areas that develop such an alternate procedure
are invited to apply to the conformity pilot program, proposed on July
9, 1996. Given the pilot program's purposes to allow greater
flexibility in implementing the rule and to evaluate potential
improvements to the rule, the pilot program is an appropriate vehicle
for this flexibility.

[[Page 43796]]

XI. Consequences of SIP Disapproval

A. Description of the Rule

    EPA is finalizing the primary option in the proposal, which is the
option for which the regulatory text was proposed. In today's final
rule, EPA is also clarifying the definition of a protective finding.
Consequences of SIP disapproval apply when control strategy SIPs are
disapproved. Control strategy SIPs are 15% SIPs, post-1996 SIPs, and
attainment demonstrations.
1. Disapproval With a Protective Finding
    When disapproving a control strategy SIP revision, EPA may give the
SIP a protective finding. If EPA disapproves a SIP but gives a
protective finding, the motor vehicle emissions budget in the
disapproved SIP could still be used to demonstrate conformity. There
would be no adverse conformity consequences unless highway sanctions
were imposed, as is the case with respect to all other SIP planning
failures. Highway sanctions would be imposed two years following EPA's
disapproval if the SIP deficiency had not been remedied. The conformity
of the plan and TIP would lapse once highway sanctions were imposed.
    EPA would give a protective finding where a submitted SIP contains
adopted control measures or written commitments to adopt enforceable
control measures that fully satisfy the emissions reductions
requirements relevant to the statutory provision for which the SIP was
submitted, such as reasonable further progress (RFP) or attainment.
That is, EPA would give such a submitted SIP a protective finding if it
contains enough emissions reduction measures or commitments to these
measures to achieve its purpose of either demonstrating RFP or
attainment. Like the November 1993 rule, a SIP could receive a
protective finding even if all control measures are not fully adopted
in enforceable form, provided there are written commitments to such
measures. EPA would not give a protective finding to a SIP whose
emission reduction measures or commitments are inadequate to achieve
the required RFP or attainment.
2. Disapproval Without a Protective Finding
    In the cases where EPA disapproves a SIP and does not give it a
protective finding, an area has a 120-day grace period, after which the
only transportation projects that could be found to conform would be
those included in the first three years of the currently conforming
transportation plan and TIP. No new plans, TIPs, or plan/TIP amendments
could be found to conform after the grace period. Further, no
additional projects not already in the first three years of the
currently conforming plan and TIP could be found to conform. Since
exempt projects and non-federal projects do not require conformity
determinations, they could proceed as long as they meet other

regionally significant non-federal project must have been included in
the regional emissions analysis supporting the most recent plan and TIP
conformity determination).
    If any one phase of a project is included in the first three years
of the currently conforming plan/TIP, all subsequent phases could
proceed following a disapproval, provided that all phases of the
project were included in the plan/TIP conformity analysis and all other
applicable project-level conformity criteria were satisfied (e.g., hot-
spot requirements).
    The ``freeze'' on new transportation plans, TIPs, and projects
would be removed once an area submits another control strategy SIP or
maintenance plan to replace the disapproved SIP, provided EPA does not
find the budget inadequate. If such a replacement SIP does not apply
for conformity purposes by the time Clean Air Act highway sanctions are
imposed (two years after EPA's final disapproval), conformity would
lapse, and no new project-level conformity determinations could be
made, even for projects in the first three years of the plan and TIP.
The lapse would last until a replacement SIP applies for conformity
purposes (i.e., until an adequate replacement SIP has been submitted to
EPA).
    During the 120-day grace period, plans, TIPs, and projects could be
found to conform using the budgets from the disapproved SIP, if there
is no applicable replacement SIP for transportation conformity
purposes. This 120-day grace period is intended to allow areas to
complete conformity determinations that were in progress at the time of
EPA's final disapproval. Both the MPO and DOT must have determined
conformity by the end of the 120-day grace period.
    As in the previous conformity rule, adverse consequences would
occur following any EPA final disapproval action on a control strategy
SIP without a protective finding, even if the disapproval is limited or
partial. The motor vehicle emissions budget is sufficient for
conformity determinations only if the SIP as a whole satisfies the
Clean Air Act requirements for RFP or attainment. If one part of a SIP
is disapproved without a protective finding, even if that part does not
address mobile sources, then there is no overall strategy for RFP or
attainment, and it is not possible to determine whether consistency
with the motor vehicle emissions budget will result in a level of
emissions consistent with RFP or attainment.
    A plan/TIP conformity lapse previously imposed under the November
1993 rule due to SIP disapproval without a protective finding would
convert to a ``freeze'' as described in this notice once this rule
becomes effective, provided highway sanctions have not yet been
imposed. The ``freeze'' would continue until highway sanctions are
imposed, which normally occurs two years after EPA's final disapproval.
Once highway sanctions are imposed, the conformity of the plan and TIP
would lapse, as occurs whether or not the SIP had received a protective
finding.
    Finally, EPA wishes to clarify that although the preamble to the
proposal inadvertently indicated that consequences of SIP disapproval
also apply to disapproval of maintenance plans, this is not what EPA
intends nor is it included in the final rule language. Consequences of
SIP disapproval only apply when control strategy SIPs are disapproved.
EPA did not refer to maintenance plans in the relevant regulatory text
of the proposal or the conformity rule as amended in 1995. The
regulatory text would not make sense with respect to maintenance plans
because sanctions do not apply for maintenance plan disapprovals.
Furthermore, there is less need to apply the consequences for
disapproving a maintenance plan, since an area could revert to using
its attainment SIP budget for demonstrating conformity if a maintenance
plan is disapproved.

B. Rationale

    EPA believes that the option finalized today provides the best
balance between the competing objectives of minimizing new
transportation commitments after a SIP disapproval and minimizing
disruption to the transportation planning process. EPA believes that
new projects should not be approved when the control strategy SIP has
been disapproved without a protective finding, because if a SIP does
not identify enough emission reductions and the motor vehicle emissions
budget does not provide for RFP or attainment, then there is no basis
to claim that a transportation activity conforms within the meaning of
Clean Air Act section 176(c). Furthermore, adding more transportation
projects may make it

[[Page 43797]]

more difficult for the air agency to create a SIP that achieves
sufficient emissions reductions, and may intensify the need for
additional control strategies later. EPA is allowing areas to
grandfather projects included in the first three years of the currently
conforming plan and TIP in order to provide stability for planning.
    Most commenters supported the primary option EPA is finalizing
today, and gave a variety of reasons. Several stakeholders commented
that this option allows some continuity for transportation planning,
since ideally it allows the TIP to continue in the short term while
changes to the SIP are underway. Another commenter noted that since
this option minimizes the disruption of projects in the first three
years of the TIP, it limits the financial and legal risk to local
governments when they undertake local bond programs to finance these
projects. Another commenter noted that SIPs may be disapproved for
numerous reasons outside of the control of the DOT or MPO, and stopping
all transportation projects immediately is not in the public's best
interest. Finally, a commenter added that since the projects that would
be allowed to proceed would have been included in a plan and TIP found
to conform previously, it seems reasonable to allow these projects to
advance.
    Some commenters supported aligning the timing of conformity
consequences of SIP disapproval with imposition of highway sanctions,
which was option 4 in the proposal. Commenters suggested that this
option would simplify communication, make the rule more consistent, and
eliminate a perceived inequity with stationary sources. However, for
the reasons stated above, EPA believes that there is no appropriate
basis to find new projects that were not included in the previously
conforming plan/TIP to conform when the SIP has been disapproved
without a protective finding. Commenters supporting option 4 did not
identify a means by which to claim that such projects would not
contribute to violations of the standards.

C. Discussion of Specific Comments

    Some objections to the legality of the primary option were raised.
One commenter objected to any project approvals based on plans and TIPs
that have lapsed, since even projects in the first three years cannot
satisfy the statutory test for coming from a conforming plan and TIP if
the conformity of the plan and TIP has lapsed. EPA agrees that projects
cannot be approved if the plan and TIP have lapsed. However, in this
situation, the conformity status of existing plans and TIPs is not
lapsing. The plan and TIP is frozen such that no new projects can be
added, but projects in the first three years can proceed to project-
level approval. EPA is grandfathering plans and TIPs that have already
been found to conform. EPA agrees that new plans and TIPs or plan/TIP
amendments cannot be found to conform after the 120-day grace period.
    Another objection raised was that EPA cannot allow plans, TIPs, or
projects to conform based on SIPs that have been disapproved, since
conformity must be based on the applicable implementation plan. EPA
agrees with this statement as well. Today's action makes it clear that
an area cannot find any new projects to conform once the SIP has been
disapproved without a protective finding. EPA is only allowing areas to
approve projects that are within the first three years of a plan and
TIP that has already been found to conform, for the two years prior to
lapsing.
    A commenter objected to codification of EPA's committal SIP policy
by the adoption of the definition of ``protective finding'' and the
authorization for protective findings in Sec. 93.120.
    EPA responds by clarifying that granting a protective finding does
not codify a committal SIP policy. By giving a SIP a protective
finding, EPA does not mean to imply that these SIPs are in any way
approvable. Rather, by disapproving the SIP, EPA is stating that the
SIP does not meet Clean Air Act SIP requirements. Granting a protective
finding merely allows an area to use the motor vehicle emissions budget
in the disapproved SIP to demonstrate conformity, where appropriate. As
other commenters stated, there are many reasons why a SIP could be
disapproved by EPA, some of which would have nothing to do with the
integrity of the motor vehicle emissions budget. A protective finding
ensures that the transportation community is not penalized as a result
of a SIP failure when the emissions budget in the SIP is adequate to
serve as the basis of a conformity determination.
    Finally, a commenter believed that prohibiting any project funding
except for grandfathered projects after the imposition of highway
sanctions (i.e., a conformity lapse) is not consistent with the policy
adopted by Congress for the imposition of sanctions. The commenter
stated that the conformity rule should be revised to explicitly adopt
the policy of prohibiting funding only for highway capacity expansion
while providing funding for all those projects that will improve air
quality identified in Clean Air Act section 179(b)(1)(B). Section
179(b)(1)(B) lists the types of projects that can proceed under
sanctions.
    However, sanctions and conformity are two different parts of the
Clean Air Act, and serve quite different purposes. Because certain
activities can proceed under sanctions does not mean that these types
of projects should not have to undergo a conformity analysis prior to
implementation, or should be permanently grandfathered from conformity
requirements. Furthermore, EPA does allow transportation control
measures in approved SIPs to proceed even during a conformity lapse.
This is consistent with the sanctions policy's provision for projects
that benefit air quality to proceed.

XII. Traffic Signal Synchronization

    On September 24, 1996, Congress amended the Clean Air Act to state
that traffic signal synchronization projects are exempt from conformity
determinations prior to their funding, approval, or implementation.
However, once these projects are funded, approved, or implemented
(whichever occurs first), they are to be included in the conformity
determinations for future transportation plans, TIPs, and projects.
    The final rule reflects this Clean Air Act amendment in new
Sec. 93.128, ``Traffic signal synchronization projects.'' This section
states that traffic signal synchronization projects may be approved,
funded, and implemented without a conformity determination. However,
all subsequent regional emissions analyses required by Secs. 93.118 and
93.119 for transportation plans, TIPs, or projects not from a
conforming plan and TIP must include such regionally significant
traffic signal synchronization projects.
    In the preamble to the proposal, prior to congressional action on
this issue, EPA had discussed whether traffic signal synchronization
projects should be exempt from conformity. This topic was included
because several stakeholders had advocated the exemption of signal
synchronization projects on the basis of positive air quality and
congestion mitigation impacts. EPA did not propose to exempt these
projects for reasons explained in the proposal's preamble. EPA received
a few comments on both sides of this issue. However, EPA is now
promulgating this change to the conformity rule without reproposing
because Congress has already amended the Clean Air Act and any
additional comments could not change the outcome. The Clean Air Act has
exempted these projects from advance

[[Page 43798]]

conformity determinations as a matter of law, and EPA is now merely
reflecting this statutory change in the regulations. EPA finds good
cause to dispense with notice and comment because EPA has no discretion
in this matter and is merely clarifying the rule to be consistent with
the amended statute.

XIII. Conformity SIPs

    As specified in the original November 1993 conformity rule and
Sec. 51.390(b) of today's final rule, the federal conformity
requirements no longer govern conformity determinations once EPA
approves a state conformity SIP revision. The provisions of the
approved SIP apply instead. Therefore, the new flexibilities found in
today's rulemaking will not take effect in areas that already have an
approved conformity SIP until the state prepares a new conformity SIP
and it is approved by EPA.
    Several stakeholders commented that this process could take too
long to give areas adequate relief. Commenters suggested several
possible solutions. For example, EPA could grant relief from the build/
no-build test without the approval of the new conformity SIP, or
today's rule could become effective upon submission of a formal
statement that the state is preparing a new conformity SIP. These
suggestions cannot be implemented because once EPA approves a state's
conformity SIP, that SIP becomes federally enforceable law, and cannot
be changed without notice-and-comment rulemaking. The conformity rule
itself cannot change the applicability of approved conformity SIPs.
    Another commenter suggested that EPA add language to the rule to
automatically approve conformity SIPs that adopt the EPA language by
reference. However, SIP approval requires public notice and comment in
the Federal Register in accordance with the APA; it cannot be given
automatically. Furthermore, there are sections of the conformity SIP,
for example, the consultation section, that cannot be adopted by
reference or verbatim because they must be tailored for the state's own
circumstances.
    However, EPA understands areas' desire to determine conformity
using the procedures in today's final rule, and EPA will give priority
to processing conformity SIP revisions designed to incorporate these
changes in those areas with approved conformity SIPs. EPA also commits
to expedite the approval of conformity SIP revisions that, to the
extent possible, incorporate the amendments verbatim or by reference.
    EPA is requiring conformity SIPs to be submitted to EPA within 12
months of today's rulemaking. One commenter stated that the 12-month
timeframe for revising conformity SIPs is too short given that state
air quality agencies would have to hire new staff to accomplish the
task, and that 12 months is inconsistent with the Clean Air Act
provisions that allow 18 months after a SIP call for an area to remedy
its deficiencies. EPA agrees that experience has shown 12 months to be
a very ambitious deadline. However, Clean Air Act section 176(c)(4)(C)
is very specific in its intent that states submit conformity SIPs
within 12 months of EPA's rules. EPA does not believe that the Clean
Air Act's general language regarding SIP calls should be used to
override the specific timeframe for submitting conformity SIPs that is
evidenced in Clean Air Act section 176(c)(4)(C). In the case of a SIP
call, EPA is allowed to establish reasonable deadlines not to exceed 18
months for an area to correct its SIP inadequacies. However, because it
cannot be argued that revising a conformity SIP to include these
amendments is more time-consuming than preparing an original conformity
SIP, there is no appropriate basis to claim that the general SIP call
language should override the specific intent of Congress regarding
deadlines for submission of conformity SIPs relative to promulgation of
federal conformity rules.

XIV. Hot-Spot Tests

    Most commenters supported the clarification to Sec. 93.123,
``Procedures for determining localized CO and PM-10 concentrations
(hot-spot analysis),'' which allows the use of procedures other than
``Guideline'' models in hot-spot analyses if the alternate procedures
are developed through the interagency consultation process and are
approved by the EPA Regional Administrator.
    A few commenters believed that the CO hot-spot requirements for all
projects affecting intersections of level of service (LOS) D, E, and F
are too stringent and burdensome when compared to the realized benefits
from such analyses. Other commenters thought that the requirements were
too prescriptive, because LOS D does not automatically indicate an air
quality problem. One commenter suggested that the conformity rule
should only require hot-spot analyses for the worst, most
representative intersection on each major street impacted by a project,
rather than all intersections that fit the current rule's hot-spot
criteria. EPA believes no change to the proposal is necessary to
address these concerns because it does have flexibility that allows
areas to develop their own protocols that have different screening
mechanisms.
    A few commenters suggested that the conformity rule should be
clarified to allow projects which decrease the likelihood of public
exposure to exceedances of the NAAQS. For example, commenters stated
that a project should be allowed to make a violation worse in a place
not frequented by the public if it improves air quality and eliminates
violations where public exposure is more likely. However, Clean Air Act
section 176(c)(1)(B) states that transportation projects must not cause
or contribute to any new violation of any standard in any area, or
increase the frequency or severity of any existing violation of any
standard in any area. It is not public exposure to a violation of a
standard that the Clean Air Act language prohibits; it prohibits any
violation of any standard in any area. The conformity rule cannot
override the Clean Air Act to make exceptions that create new or worsen
existing violations.

XV. TCM Flexibility

    As discussed in the proposal preamble, EPA remains committed to
issuing guidance on how areas can substitute TCMs in previously
approved SIPs without additional EPA approvals. EPA also stated in the
proposal that development of such a substitution mechanism is possible
under existing EPA SIP policy, so this final rule does not address the
issue.

XVI. Conformity and the Proposed NAAQS Revisions

    Several commenters requested information on how the revisions of
the ozone and particulate matter (PM) NAAQS standards would affect
conformity. EPA issued a notice of proposed policy entitled, ``Interim
Implementation Policy on New or Revised Ozone and Particulate Matter
NAAQS'' (61 FR 65752, December 13, 1996), which proposes how current
programs would be affected while states are developing plans to
implement the new NAAQS. This proposed policy notice specifically
discusses conformity. A final policy for implementing the one hour
ozone and pre-existing PM NAAQS will be published in the Federal
Register in September 1997.
    EPA proposed in its December 1996 notice that conformity
determinations would not be required to address the new NAAQS until
SIPs addressing the new NAAQS are approved by EPA. New nonattainment
areas would not be subject to conformity until EPA approves the SIPs
that address these

[[Page 43799]]

standards. Existing nonattainment and maintenance areas would not have
to consider the 8-hour ozone standard or the PM-2.5 standard in their
conformity determinations until EPA approved SIPs addressing those
pollutants.
    In general, the existing control strategy SIPs and maintenance
plans that establish motor vehicle emissions budgets will remain in
force until they are superseded by new or revised SIPs that have been
approved by EPA. Thus, conformity will continue as usual in existing
nonattainment and maintenance areas for several years. Areas that have
not submitted post-1996 rate-of-progress plans or attainment
demonstrations for the one hour ozone standard would be required to
conform to the 15% SIP until a post-1996 plan or new attainment
demonstration is submitted.
    In such areas, conformity to that plan would not be required, and
these areas would continue to demonstrate conformity to the 15% SIP.
Areas that are not required to submit control strategy SIPs (e.g.,
marginal areas) and have not been demonstrating conformity to motor
vehicle emissions budgets would be required to continue demonstrating
conformity using the emission reduction tests until SIPs with motor
vehicle emissions budgets are submitted. Areas with approved
maintenance plans would continue demonstrating conformity using the
budgets established by those plans.
    States are free to establish, through the SIP process, a motor
vehicle emissions budget that addresses the new NAAQS in advance of a
complete SIP attainment demonstration. That is, a state could submit a
motor vehicle emissions budget that does not demonstrate attainment but
is consistent with projections and commitments to control measures and
achieves some progress toward attainment. Such a budget would apply for
conformity purposes in addition to existing budgets addressing the old
NAAQS (i.e., a SIP that does not demonstrate attainment of the new
NAAQS would not supersede existing control strategy SIPs).
    Today's final conformity rule does not include any changes
specifically intended to address the NAAQS revisions. No changes are
necessary in the short term because the existing conformity process
will continue for several years. The Federal Advisory Committee Act
(FACA) Subcommittee for Ozone, PM and Regional Haze Implementation
Programs is discussing the longer-term conformity issues, and EPA's
decisions will be published in future policy notices. In addition, EPA
will be promulgating a conformity rule addressing transitional ozone
areas under the new standard by December 1998.

XVII. Minor Changes to the Rule

A. Definitions

    This final rule includes three new definitions in Sec. 93.101. For
the purposes of this final rule, EPA has defined ``written commitment''
to mean a commitment that includes a description of the action to be
taken; a schedule for the completion of the action; a demonstration
that funding necessary to implement the action has been authorized by
the appropriating or authorizing body; and an acknowledgment that the
commitment is an enforceable obligation under the SIP. The conformity
rule uses the term ``written commitment'' with respect to SIP
commitments to control measures, and also with respect to commitments
to project-level emissions mitigation or control measures as part of a
conformity determination. As described in Sec. 93.125(c), these latter
commitments are enforceable under the conformity SIP. As is the case
with any other type of SIP commitments, written commitments as defined
by the conformity rule must be made by an agency that has legal
authority to implement the action in question.
    EPA is defining the term ``written commitment'' because a commenter
requested it, and EPA agrees that this will ease implementation by
clarifying EPA's intent. This definition is consistent with EPA's
historical implementation of the conformity rule.
    EPA is also defining the term ``safety margin'' to mean the amount
by which the total projected emissions from all sources of a given
pollutant are less than the total emissions that would satisfy the
applicable Clean Air Act requirement for reasonable further progress,
attainment, or maintenance. EPA has added a reference to that term in
Sec. 93.118(e)(4), which lists the requirements for the adequacy of
submitted SIPs. This section specifies that documentation of any
changes to established safety margins is a criterion for the adequacy
of a submitted SIP. The term ``safety margin'' is also used in
Sec. 93.124(b), although it is used and defined in that section in a
specific context. This definition is consistent with the historical
implementation of the conformity rule and with the definition in
Sec. 93.124(b).
    EPA is defining ``lapse'' to mean that the conformity determination
for a transportation plan or TIP has expired, and thus there is no
currently conforming transportation plan and TIP.

B. Consultation

    EPA is making two minor changes to the consultation section in
response to comments on the proposal. One commenter suggested that the
public consultation requirements of Sec. 93.105(e) should be included
in the conformity SIP. EPA agrees with this commenter and has modified
Sec. 93.105(a) to clarify that the public consultation requirements
described in Sec. 93.105(e) must also be required by the conformity
SIP. Because the federal conformity rule ceases to apply once the
conformity SIP has been approved, the requirements of Sec. 93.105(e)
must be required by the conformity SIP or the SIP would not provide for
appropriate public input.
    Section 93.105(e) requires public consultation consistent with the
requirements of 23 CFR 450.316(b) and articulates a few specific
requirements. EPA intends for the conformity SIP to reiterate these
statements; EPA does not intend for the conformity SIP to actually
include the specific public consultation procedures that an area
develops under 23 CFR 450.316(b).
    EPA is also adding a new element to the list of processes for which
consultation procedures must be developed. Section 93.105(c)(1)(vii)
requires areas to establish a process for choosing conformity tests and
methodologies for isolated rural nonattainment and maintenance areas,
as required by Sec. 93.109(g)(2)(iii). (Refer to section V. of this
preamble, ``Rural Nonattainment and Maintenance Areas'' for a
discussion of the choices of conformity tests that are available to
rural areas.) Of course, states without isolated rural nonattainment
and maintenance areas would not need to develop such procedures.
    As explained in the proposal preamble, EPA had not proposed to
amend Sec. 51.402/Sec. 93.105 of the original conformity rule to add
this element to the list of processes for which consultation procedures
must be developed, because EPA believed it was clear that consultation
would be necessary to use the new rural provision. Commenters had mixed
opinions about whether and how the new consultation needs should be
integrated into the conformity rule. Some commenters did not believe
that the conformity rule needed to be changed. However, some thought
that further guidance regarding necessary changes in areas'
consultation procedures would be useful. Given these comments, EPA
decided to add the new consultation requirement to the conformity rule
for clarity and so that the rule could serve as a comprehensive

[[Page 43800]]

list of items that consultation procedures must address.
    One commenter requested that EPA explain that Memoranda of
Understanding, or MOUs, can be used to establish interagency
consultation procedures. The commenter is correct that MOUs can be used
to establish interagency consultation procedures, provided that the MOU
is enforceable under state law. In order for the MOU to be enforceable,
all agencies that are covered by the conformity rule must sign the MOU,
including federal agencies and the recipients of funds designated under
title 23 U.S.C. or the Federal Transit Laws (i.e., non-federal project
sponsors). In addition, the conformity SIP must include a rule that
requires all future parties covered by the rule, including new
recipients of funds designated under title 23 U.S.C. or the Federal
Transit Laws, to sign the MOU. This ensures that the MOU approach will
continue to apply to all subject parties. EPA does not believe that any
regulatory changes are needed to address this issue.

C. Changes to Sec. 93.109

    Section 93.109, ``Criteria and procedures for determining
conformity of transportation plans, programs, and projects: General,''
describes which conformity tests apply and when they apply for each
pollutant and for rural areas. This section has been revised to reflect
changes discussed elsewhere in this preamble. In addition, this section
has been slightly revised so that its description of conformity
requirements does not refer solely to an area's nonattainment
classification. The section now also refers to the control strategy SIP
requirements for a given classification. EPA believes this clarifies
the conformity rule and makes it more flexible in the case of future
revisions to the classification system, which could occur if the NAAQS
are revised. These clarifications do not change the substance of the
section's requirements.

XVIII. Administrative Requirements

A. Administrative Designation

Executive Order 12866
    Under Executive Order 12866, (58 FR 51735 (October 4, 1993)) the
Agency must determine whether the regulatory action is ``significant''
and therefore subject to OMB review and the requirements of the
Executive Order. The Order defines ``significant regulatory action'' as
one that is likely to result in a rule that may:
    (1) Have an annual effect on the economy of $100 million or more,
or otherwise adversely affect in a material way the economy, a sector
of the economy, productivity, competition, jobs, the environment,
public health or safety, or state, local, or tribal governments or
communities;
    (2) Create a serious inconsistency or otherwise interfere with an
action taken or planned by another agency;
    (3) Materially alter the budgetary impact of entitlements, grants,
user fees, or loan programs or the rights and obligations of recipients
thereof;
    (4) Raise novel or policy issues arising out of legal mandates, the
President's priorities, or the principles set forth in the Executive
Order.
    Pursuant to the terms of Executive Order 12866, it has been
determined that this rule is a ``significant regulatory action''
because this action raises novel legal or policy issues arising out of
legal mandates, the President's priorities, and the principles set
forth in the Executive Order. As such, this action was submitted to OMB
for review. Changes made in response to OMB suggestions or
recommendations will be documented in the public record.

B. Paperwork Reduction Act

    This final rule does not impose any new information collection
requirements and results in no change to the currently approved
collection requirements. OMB has approved the information collection
requirements contained in this rule under the provisions of the
Paperwork Reduction Act, 44 U.S.C. 3501 et seq.
    The information collection requirements of EPA's Transportation
Conformity Rule and these amendments to it are covered under the
Information Collection Request of the Department of Transportation
entitled, ``Metropolitan and Statewide Transportation Planning,''
approved by OMB under the Paperwork Reduction Act, and assigned OMB
Control Number 2132-0529.
    Burden means the total time, effort, or financial resources
expended by persons to generate, maintain, retain, or disclose or
provide information to or for a federal agency. This includes the time
needed to review instructions; develop, acquire, install, and utilize
technology and systems for the purposes of collecting, validating, and
verifying information, processing and maintaining information, and
disclosing and providing information; adjust the existing ways to
comply with any previously applicable instructions and requirements;
train personnel to be able to respond to a collection of information;
search data sources; complete and review the collection of information;
and transmit or otherwise disclose the information.
    An Agency may not conduct or sponsor, and a person is not required
to respond to a collection of information unless it displays a
currently valid OMB control number. The OMB control numbers for DOT's
regulations are listed in 5 CFR Part 1320.
    Send any comments on the recordkeeping and reporting requirements
of Transportation Conformity to: Mr. Sean Libberton, U.S. Department of
Transportation, TPL11, 400 7th Street, SW., Washington, DC 20590, and
Office of Information and Regulatory Affairs, Office of Management and
Budget, Attention: Desk Officer for EPA/OAR, Room 10202, 725 17th
Street, NW., Washington, DC 20503. In any correspondence please refer
to OMB Control Number 2132-0529.

C. Regulatory Flexibility Analysis

    The Regulatory Flexibility Act of 1980 requires federal agencies to
identify potentially adverse impacts of federal regulations upon small
entities. In instances where significant impacts are possible on a
substantial number of these entities, agencies are required to perform
a Regulatory Flexibility Analysis (RFA).
    EPA has determined that today's regulations will not have a
significant impact on a substantial number of small entities. This
regulation affects federal agencies and metropolitan planning
organizations, which by definition are designated only for metropolitan
areas with a population of at least 50,000. These organizations do not
constitute small entities.
    Therefore, as required under section 605 of the Regulatory
Flexibility Act, 5 U.S.C. 601 et seq., I certify that this rule will
not have a significant economic impact on a substantial number of small
entities.

D. Submission to Congress and the Comptroller General

    Under 5 U.S.C. 801(a)(1)(A), as added by the Small Business
Regulatory Enforcement Fairness Act of 1996, EPA submitted a report
containing this rule and other required information to the U.S. Senate,
the U.S. House of Representatives, and the Comptroller General of the
United States prior to publication of the rule in today's Federal
Register. This rule is not a ``major rule'' as defined by 5 U.S.C.
804(2).

E. Unfunded Mandates

    Under Sections 202, 203, and 205 of the Unfunded Mandates Reform
Act of 1995 (``Unfunded Mandates Act''), signed into law on March 22,
1995, EPA

[[Page 43801]]

must undertake various actions in association with proposed or final
rules that include a federal mandate that may result in estimated costs
of $100 million or more to the private sector, or to state, local, or
tribal governments in the aggregate.
    EPA has determined that to the extent this rule imposes any mandate
within the meaning of the Unfunded Mandates Act, this final action does
not include a mandate that may result in estimated costs of $100
million or more to state, local, or tribal governments in the aggregate
or to the private sector. These rule amendments relax requirements of
the previously applicable conformity rule, and thus do not impose any
additional burdens. Therefore, EPA has not prepared a statement with
respect to budgetary impacts.

List of Subjects

40 CFR Part 51

    Environmental protection, Administrative practice and procedure,
Air pollution control, Carbon monoxide, Intergovernmental relations,
Nitrogen dioxide, Ozone, Particulate matter, Reporting and
recordkeeping requirements, Transportation, Volatile organic compounds.

40 CFR Part 93

    Administrative practice and procedure, Air pollution control,
Carbon monoxide, Intergovernmental relations, Nitrogen dioxide, Ozone,
Particulate matter, Transportation, Volatile organic compounds.

    Dated: July 31, 1997.
Carol M. Browner,
Administrator.

    For the reasons set out in the preamble, 40 CFR parts 51 and 93 are
amended as follows:

PART 51--[AMENDED]

    1. The authority citation for part 51 is revised to read as
follows:

    Authority: 42 U.S.C. 7401-7671q.

    2. Subpart T is revised to read as follows:

Subpart T--Conformity to State or Federal Implementation Plans of
Transportation Plans, Programs, and Projects Developed, Funded or
Approved Under Title 23 U.S.C. or the Federal Transit Laws

Sec. 51.390  Implementation plan revision.

    (a) States with areas subject to this subpart and part 93, subpart
A, of this chapter must submit to the EPA and DOT a revision to their
implementation plan which contains criteria and procedures for DOT,
MPOs and other State or local agencies to assess the conformity of
transportation plans, programs, and projects, consistent with this
subpart and part 93, subpart A, of this chapter. This revision is to be
submitted by November 25, 1994 (or within 12 months of an area's
redesignation from attainment to nonattainment, if the State has not
previously submitted such a revision). Further revisions to the
implementation plan required by amendments to part 93, subpart A, of
this chapter must be submitted within 12 months of the date of
publication of such final amendments. EPA will provide DOT with a 30-
day comment period before taking action to approve or disapprove the
submission. A State's conformity provisions may contain criteria and
procedures more stringent than the requirements described in this
subpart and part 93, subpart A, of this chapter only if the State's
conformity provisions apply equally to non-federal as well as Federal
entities.
    (b) The Federal conformity rules under part 93, subpart A, of this
chapter, in addition to any existing applicable State requirements,
establish the conformity criteria and procedures necessary to meet the
requirements of Clean Air Act section 176(c) until such time as EPA
approves the conformity implementation plan revision required by this
subpart. Following EPA approval of the State conformity provisions (or
a portion thereof) in a revision to the applicable implementation plan,
conformity determinations would be governed by the approved (or
approved portion of the) State criteria and procedures. The Federal
conformity regulations contained in part 93, subpart A, of this chapter
would apply only for the portion, if any, of the State's conformity
provisions that is not approved by EPA. In addition, any previously
applicable implementation plan conformity requirements remain
enforceable until the State submits a revision to its applicable
implementation plan to specifically remove them and that revision is
approved by EPA.
    (c) The implementation plan revision required by this section must
meet all of the requirements of part 93, subpart A, of this chapter.
    (d) In order for EPA to approve the implementation plan revision
submitted to EPA and DOT under this subpart, the plan must address all
requirements of part 93, subpart A, of this chapter in a manner which
gives them full legal effect. In particular, the revision shall
incorporate the provisions of the following sections of part 93,
subpart A, of this chapter in verbatim form, except insofar as needed
to clarify or to give effect to a stated intent in the revision to
establish criteria and procedures more stringent than the requirements
stated in the following sections of this chapter: Secs. 93.101, 93.102,
93.103, 93.104, 93.106, 93.109, 93.110, 93.111, 93.112, 93.113, 93.114,
93.115, 93.116, 93.117, 93.118, 93.119, 93.120, 93.121, 93.126, and
93.127.

PART 93--[AMENDED]

    3. The authority citation for part 93 continues to read as follows:

    Authority: 42 U.S.C. 7401-7671q.

    4. Subpart A is revised to read as follows:

Subpart A--Conformity to State or Federal Implementation Plans of
Transportation Plans, Programs, and Projects Developed, Funded or
Approved Under Title 23 U.S.C. or the Federal Transit Laws

Sec.
93.100  Purpose.
93.101  Definitions.
93.102  Applicability.
93.103  Priority.
93.104  Frequency of conformity determinations.
93.105  Consultation.
93.106  Content of transportation plans.
93.107  Relationship of transportation plan and TIP conformity with
the NEPA process.
93.108  Fiscal constraints for transportation plans and TIPs.
93.109  Criteria and procedures for determining conformity of
transportation plans, programs, and projects: General.
93.110  Criteria and procedures: Latest planning assumptions.
93.111  Criteria and procedures: Latest emissions model.
93.112  Criteria and procedures: Consultation.
93.113  Criteria and procedures: Timely implementation of TCMs.
93.114  Criteria and procedures: Currently conforming transportation
plan and TIP.
93.115  Criteria and procedures: Projects from a plan and TIP.
93.116  Criteria and procedures: Localized CO and PM10
violations (hot spots).
93.117  Criteria and procedures: Compliance with PM10
control measures.
93.118  Criteria and procedures: Motor vehicle emissions budget.
93.119  Criteria and procedures: Emission reductions in areas
without motor vehicle emissions budgets.
93.120   Consequences of control strategy implementation plan
failures.
93.121  Requirements for adoption or approval of projects by other
recipients of funds designated under title 23 U.S.C. or the Federal
Transit Laws.
93.122  Procedures for determining regional transportation-related
emissions.
93.123  Procedures for determining localized CO and PM10
concentrations (hot-spot analysis).

[[Page 43802]]

93.124  Using the motor vehicle emissions budget in the applicable
implementation plan (or implementation plan submission).
93.125  Enforceability of design concept and scope and project-level
mitigation and control measures.
93.126  Exempt projects.
93.127  Projects exempt from regional emissions analyses.
93.128  Traffic signal synchronization projects.

Subpart A--Conformity to State or Federal Implementation Plans of
Transportation Plans, Programs, and Projects Developed, Funded or
Approved Under Title 23 U.S.C. or the Federal Transit Laws

Sec. 93.100  Purpose.

    The purpose of this subpart is to implement section 176(c) of the
Clean Air Act (CAA), as amended (42 U.S.C. 7401 et seq.), and the
related requirements of 23 U.S.C. 109(j), with respect to the
conformity of transportation plans, programs, and projects which are
developed, funded, or approved by the United States Department of
Transportation (DOT), and by metropolitan planning organizations (MPOs)
or other recipients of funds under title 23 U.S.C. or the Federal
Transit Laws (49 U.S.C. Chapter 53). This subpart sets forth policy,
criteria, and procedures for demonstrating and assuring conformity of
such activities to an applicable implementation plan developed pursuant
to section 110 and Part D of the CAA.

Sec. 93.101  Definitions.

    Terms used but not defined in this subpart shall have the meaning
given them by the CAA, titles 23 and 49 U.S.C., other Environmental
Protection Agency (EPA) regulations, or other DOT regulations, in that
order of priority.
    Applicable implementation plan is defined in section 302(q) of the
CAA and means the portion (or portions) of the implementation plan, or
most recent revision thereof, which has been approved under section
110, or promulgated under section 110(c), or promulgated or approved
pursuant to regulations promulgated under section 301(d) and which
implements the relevant requirements of the CAA.
    CAA means the Clean Air Act, as amended (42 U.S.C. 7401 et seq.).
    Cause or contribute to a new violation for a project means:
    (1) To cause or contribute to a new violation of a standard in the
area substantially affected by the project or over a region which would
otherwise not be in violation of the standard during the future period
in question, if the project were not implemented; or
    (2) To contribute to a new violation in a manner that would
increase the frequency or severity of a new violation of a standard in
such area.
    Clean data means air quality monitoring data determined by EPA to
meet the requirements of 40 CFR part 58 that indicate attainment of the
national ambient air quality standard.
    Control strategy implementation plan revision is the implementation
plan which contains specific strategies for controlling the emissions
of and reducing ambient levels of pollutants in order to satisfy CAA
requirements for demonstrations of reasonable further progress and
attainment (CAA sections 182(b)(1), 182(c)(2)(A), 182(c)(2)(B),
187(a)(7), 189(a)(1)(B), and 189(b)(1)(A); and sections 192(a) and
192(b), for nitrogen dioxide).
    Design concept means the type of facility identified by the
project, e.g., freeway, expressway, arterial highway, grade-separated
highway, reserved right-of-way rail transit, mixed-traffic rail
transit, exclusive busway, etc.
    Design scope means the design aspects which will affect the
proposed facility's impact on regional emissions, usually as they
relate to vehicle or person carrying capacity and control, e.g., number
of lanes or tracks to be constructed or added, length of project,
signalization, access control including approximate number and location
of interchanges, preferential treatment for high-occupancy vehicles,
etc.
    DOT means the United States Department of Transportation.
    EPA means the Environmental Protection Agency.
    FHWA means the Federal Highway Administration of DOT.
    FHWA/FTA project, for the purpose of this subpart, is any highway
or transit project which is proposed to receive funding assistance and
approval through the Federal-Aid Highway program or the Federal mass
transit program, or requires Federal Highway Administration (FHWA) or
Federal Transit Administration (FTA) approval for some aspect of the
project, such as connection to an interstate highway or deviation from
applicable design standards on the interstate system.
    Forecast period with respect to a transportation plan is the period
covered by the transportation plan pursuant to 23 CFR part 450.
    FTA means the Federal Transit Administration of DOT.
    Highway project is an undertaking to implement or modify a highway
facility or highway-related program. Such an undertaking consists of
all required phases necessary for implementation. For analytical
purposes, it must be defined sufficiently to:
    (1) Connect logical termini and be of sufficient length to address
environmental matters on a broad scope;
    (2) Have independent utility or significance, i.e., be usable and
be a reasonable expenditure even if no additional transportation
improvements in the area are made; and
    (3) Not restrict consideration of alternatives for other reasonably
foreseeable transportation improvements.
    Horizon year is a year for which the transportation plan describes
the envisioned transportation system according to Sec. 93.106.
    Hot-spot analysis is an estimation of likely future localized CO
and PM10 pollutant concentrations and a comparison of those
concentrations to the national ambient air quality standards. Hot-spot
analysis assesses impacts on a scale smaller than the entire
nonattainment or maintenance area, including, for example, congested
roadway intersections and highways or transit terminals, and uses an
air quality dispersion model to determine the effects of emissions on
air quality.
    Increase the frequency or severity means to cause a location or
region to exceed a standard more often or to cause a violation at a
greater concentration than previously existed and/or would otherwise
exist during the future period in question, if the project were not
implemented.
    Lapse means that the conformity determination for a transportation
plan or TIP has expired, and thus there is no currently conforming
transportation plan and TIP.
    Maintenance area means any geographic region of the United States
previously designated nonattainment pursuant to the CAA Amendments of
1990 and subsequently redesignated to attainment subject to the
requirement to develop a maintenance plan under section 175A of the
CAA, as amended.
    Maintenance plan means an implementation plan under section 175A of
the CAA, as amended.
    Metropolitan planning organization (MPO) is that organization
designated as being responsible, together with the State, for
conducting the continuing, cooperative, and comprehensive planning
process under 23 U.S.C. 134 and 49 U.S.C. 5303. It is the forum for
cooperative transportation decision-making.
    Milestone has the meaning given in sections 182(g)(1) and 189(c) of
the CAA. A milestone consists of an

[[Page 43803]]

emissions level and the date on which it is required to be achieved.
    Motor vehicle emissions budget is that portion of the total
allowable emissions defined in the submitted or approved control
strategy implementation plan revision or maintenance plan for a certain
date for the purpose of meeting reasonable further progress milestones
or demonstrating attainment or maintenance of the NAAQS, for any
criteria pollutant or its precursors, allocated to highway and transit
vehicle use and emissions.
    National ambient air quality standards (NAAQS) are those standards
established pursuant to section 109 of the CAA.
    NEPA means the National Environmental Policy Act of 1969, as
amended (42 U.S.C. 4321 et seq.).
    NEPA process completion, for the purposes of this subpart, with
respect to FHWA or FTA, means the point at which there is a specific
action to make a determination that a project is categorically
excluded, to make a Finding of No Significant Impact, or to issue a
record of decision on a Final Environmental Impact Statement under
NEPA.
    Nonattainment area means any geographic region of the United States
which has been designated as nonattainment under section 107 of the CAA
for any pollutant for which a national ambient air quality standard
exists.
    Project means a highway project or transit project.
    Protective finding means a determination by EPA that a submitted
control strategy implementation plan revision contains adopted control
measures or written commitments to adopt enforceable control measures
that fully satisfy the emissions reductions requirements relevant to
the statutory provision for which the implementation plan revision was
submitted, such as reasonable further progress or attainment.
    Recipient of funds designated under title 23 U.S.C. or the Federal
Transit Laws means any agency at any level of State, county, city, or
regional government that routinely receives title 23 U.S.C. or Federal
Transit Laws funds to construct FHWA/FTA projects, operate FHWA/FTA
projects or equipment, purchase equipment, or undertake other services
or operations via contracts or agreements. This definition does not
include private landowners or developers, or contractors or entities
that are only paid for services or products created by their own
employees.
    Regionally significant project means a transportation project
(other than an exempt project) that is on a facility which serves
regional transportation needs (such as access to and from the area
outside of the region, major activity centers in the region, major
planned developments such as new retail malls, sports complexes, etc.,
or transportation terminals as well as most terminals themselves) and
would normally be included in the modeling of a metropolitan area's
transportation network, including at a minimum all principal arterial
highways and all fixed guideway transit facilities that offer an
alternative to regional highway travel.
    Safety margin means the amount by which the total projected
emissions from all sources of a given pollutant are less than the total
emissions that would satisfy the applicable requirement for reasonable
further progress, attainment, or maintenance.
    Standard means a national ambient air quality standard.
    Transit is mass transportation by bus, rail, or other conveyance
which provides general or special service to the public on a regular
and continuing basis. It does not include school buses or charter or
sightseeing services.
    Transit project is an undertaking to implement or modify a transit
facility or transit-related program; purchase transit vehicles or
equipment; or provide financial assistance for transit operations. It
does not include actions that are solely within the jurisdiction of
local transit agencies, such as changes in routes, schedules, or fares.
It may consist of several phases. For analytical purposes, it must be
defined inclusively enough to:
    (1) Connect logical termini and be of sufficient length to address
environmental matters on a broad scope;
    (2) Have independent utility or independent significance, i.e., be
a reasonable expenditure even if no additional transportation
improvements in the area are made; and
    (3) Not restrict consideration of alternatives for other reasonably
foreseeable transportation improvements.
    Transportation control measure (TCM) is any measure that is
specifically identified and committed to in the applicable
implementation plan that is either one of the types listed in section
108 of the CAA, or any other measure for the purpose of reducing
emissions or concentrations of air pollutants from transportation
sources by reducing vehicle use or changing traffic flow or congestion
conditions. Notwithstanding the first sentence of this definition,
vehicle technology-based, fuel-based, and maintenance-based measures
which control the emissions from vehicles under fixed traffic
conditions are not TCMs for the purposes of this subpart.
    Transportation improvement program (TIP) means a staged, multiyear,
intermodal program of transportation projects covering a metropolitan
planning area which is consistent with the metropolitan transportation
plan, and developed pursuant to 23 CFR part 450.
    Transportation plan means the official intermodal metropolitan
transportation plan that is developed through the metropolitan planning
process for the metropolitan planning area, developed pursuant to 23
CFR part 450.
    Transportation project is a highway project or a transit project.
    Written commitment for the purposes of this subpart means a written
commitment that includes a description of the action to be taken; a
schedule for the completion of the action; a demonstration that funding
necessary to implement the action has been authorized by the
appropriating or authorizing body; and an acknowledgment that the
commitment is an enforceable obligation under the applicable
implementation plan.

Sec. 93.102  Applicability.

    (a) Action applicability.
    (1) Except as provided for in paragraph (c) of this section or
Sec. 93.126, conformity determinations are required for:
    (i) The adoption, acceptance, approval or support of transportation
plans and transportation plan amendments developed pursuant to 23 CFR
part 450 or 49 CFR part 613 by an MPO or DOT;
    (ii) The adoption, acceptance, approval or support of TIPs and TIP
amendments developed pursuant to 23 CFR part 450 or 49 CFR part 613 by
an MPO or DOT; and
    (iii) The approval, funding, or implementation of FHWA/FTA
projects.
    (2) Conformity determinations are not required under this subpart
for individual projects which are not FHWA/FTA projects. However,
Sec. 93.121 applies to such projects if they are regionally
significant.
    (b) Geographic applicability. The provisions of this subpart shall
apply in all nonattainment and maintenance areas for transportation-
related criteria pollutants for which the area is designated
nonattainment or has a maintenance plan.
    (1) The provisions of this subpart apply with respect to emissions
of the following criteria pollutants: ozone, carbon monoxide (CO),
nitrogen dioxide

[[Page 43804]]

(NO2), and particles with an aerodynamic diameter less than
or equal to a nominal 10 micrometers (PM10).
    (2) The provisions of this subpart apply with respect to emissions
of the following precursor pollutants:
    (i) Volatile organic compounds (VOC) and nitrogen oxides
(NOX) in ozone areas;
    (ii) NOX in NO2 areas; and
    (iii) VOC, NOX, and PM10 in PM10
areas if the EPA Regional Administrator or the director of the State
air agency has made a finding that transportation-related precursor
emissions within the nonattainment area are a significant contributor
to the PM10 nonattainment problem and has so notified the
MPO and DOT, or if the applicable implementation plan (or
implementation plan submission) establishes a budget for such emissions
as part of the reasonable further progress, attainment or maintenance
strategy.
    (3) The provisions of this subpart apply to maintenance areas for
20 years from the date EPA approves the area's request under section
107(d) of the CAA for redesignation to attainment, unless the
applicable implementation plan specifies that the provisions of this
subpart shall apply for more than 20 years.
    (c) Limitations. (1) Projects subject to this subpart for which the
NEPA process and a conformity determination have been completed by DOT
may proceed toward implementation without further conformity
determinations unless more than three years have elapsed since the most
recent major step (NEPA process completion; start of final design;
acquisition of a significant portion of the right-of-way; or approval
of the plans, specifications and estimates) occurred. All phases of
such projects which were considered in the conformity determination are
also included, if those phases were for the purpose of funding final
design, right-of-way acquisition, construction, or any combination of
these phases.
    (2) A new conformity determination for the project will be required
if there is a significant change in project design concept and scope,
if a supplemental environmental document for air quality purposes is
initiated, or if three years have elapsed since the most recent major
step to advance the project occurred.
    (d) Grace period for new nonattainment areas. For areas or portions
of areas which have been designated attainment for either ozone, CO,
PM10 or NO2 since 1990 and are subsequently
redesignated to nonattainment for any of these pollutants, the
provisions of this subpart shall not apply for 12 months following the
date of final designation to nonattainment for such pollutant.

Sec. 93.103  Priority.

    When assisting or approving any action with air quality-related
consequences, FHWA and FTA shall give priority to the implementation of
those transportation portions of an applicable implementation plan
prepared to attain and maintain the NAAQS. This priority shall be
consistent with statutory requirements for allocation of funds among
States or other jurisdictions.

Sec. 93.104  Frequency of conformity determinations.

    (a) Conformity determinations and conformity redeterminations for
transportation plans, TIPs, and FHWA/FTA projects must be made
according to the requirements of this section and the applicable
implementation plan.
    (b) Frequency of conformity determinations for transportation
plans. (1) Each new transportation plan must be demonstrated to conform
before the transportation plan is approved by the MPO or accepted by
DOT.
    (2) All transportation plan revisions must be found to conform
before the transportation plan revisions are approved by the MPO or
accepted by DOT, unless the revision merely adds or deletes exempt
projects listed in Sec. 93.126 or Sec. 93.127. The conformity
determination must be based on the transportation plan and the revision
taken as a whole.
    (3) The MPO and DOT must determine the conformity of the
transportation plan no less frequently than every three years. If more
than three years elapse after DOT's conformity determination without
the MPO and DOT determining conformity of the transportation plan, the
existing conformity determination will lapse.
    (c) Frequency of conformity determinations for transportation
improvement programs. (1) A new TIP must be demonstrated to conform
before the TIP is approved by the MPO or accepted by DOT.
    (2) A TIP amendment requires a new conformity determination for the
entire TIP before the amendment is approved by the MPO or accepted by
DOT, unless the amendment merely adds or deletes exempt projects listed
in Sec. 93.126 or Sec. 93.127.
    (3) The MPO and DOT must determine the conformity of the TIP no
less frequently than every three years. If more than three years elapse
after DOT's conformity determination without the MPO and DOT
determining conformity of the TIP, the existing conformity
determination will lapse.
    (4) After an MPO adopts a new or revised transportation plan,
conformity of the TIP must be redetermined by the MPO and DOT within
six months from the date of DOT's conformity determination for the
transportation plan, unless the new or revised plan merely adds or
deletes exempt projects listed in Secs. 93.126 and 93.127. Otherwise,
the existing conformity determination for the TIP will lapse.
    (d) Projects. FHWA/FTA projects must be found to conform before
they are adopted, accepted, approved, or funded. Conformity must be
redetermined for any FHWA/FTA project if three years have elapsed since
the most recent major step to advance the project (NEPA process
completion; start of final design; acquisition of a significant portion
of the right-of-way; or approval of the plans, specifications and
estimates) occurred.
    (e) Triggers for transportation plan and TIP conformity
determinations. Conformity of existing transportation plans and TIPs
must be redetermined within 18 months of the following, or the existing
conformity determination will lapse, and no new project-level
conformity determinations may be made until conformity of the
transportation plan and TIP has been determined by the MPO and DOT:
    (1) November 24, 1993;
    (2) The date of the State's initial submission to EPA of each
control strategy implementation plan or maintenance plan establishing a
motor vehicle emissions budget;
    (3) EPA approval of a control strategy implementation plan revision
or maintenance plan which establishes or revises a motor vehicle
emissions budget;
    (4) EPA approval of an implementation plan revision that adds,
deletes, or changes TCMs; and
    (5) EPA promulgation of an implementation plan which establishes or
revises a motor vehicle emissions budget or adds, deletes, or changes
TCMs.

Sec. 93.105  Consultation.

    (a) General. The implementation plan revision required under
Sec. 51.390 of this chapter shall include procedures for interagency
consultation (Federal, State, and local), resolution of conflicts, and
public consultation as described in paragraphs (a) through (e) of this
section. Public consultation procedures will be developed in accordance
with the requirements for public involvement in 23 CFR part 450.

[[Page 43805]]

    (1) The implementation plan revision shall include procedures to be
undertaken by MPOs, State departments of transportation, and DOT with
State and local air quality agencies and EPA before making conformity
determinations, and by State and local air agencies and EPA with MPOs,
State departments of transportation, and DOT in developing applicable
implementation plans.
    (2) Before EPA approves the conformity implementation plan revision
required by Sec. 51.390 of this chapter, MPOs and State departments of
transportation must provide reasonable opportunity for consultation
with State air agencies, local air quality and transportation agencies,
DOT, and EPA, including consultation on the issues described in
paragraph (c)(1) of this section, before making conformity
determinations.
    (b) Interagency consultation procedures: General factors. (1)
States shall provide well-defined consultation procedures in the
implementation plan whereby representatives of the MPOs, State and
local air quality planning agencies, State and local transportation
agencies, and other organizations with responsibilities for developing,
submitting, or implementing provisions of an implementation plan
required by the CAA must consult with each other and with local or
regional offices of EPA, FHWA, and FTA on the development of the
implementation plan, the transportation plan, the TIP, and associated
conformity determinations.
    (2) Interagency consultation procedures shall include at a minimum
the following general factors and the specific processes in paragraph
(c) of this section:
    (i) The roles and responsibilities assigned to each agency at each
stage in the implementation plan development process and the
transportation planning process, including technical meetings;
    (ii) The organizational level of regular consultation;
    (iii) A process for circulating (or providing ready access to)
draft documents and supporting materials for comment before formal
adoption or publication;
    (iv) The frequency of, or process for convening, consultation
meetings and responsibilities for establishing meeting agendas;
    (v) A process for responding to the significant comments of
involved agencies; and
    (vi) A process for the development of a list of the TCMs which are
in the applicable implementation plan.
    (c) Interagency consultation procedures: Specific processes.
Interagency consultation procedures shall also include the following
specific processes:
    (1) A process involving the MPO, State and local air quality
planning agencies, State and local transportation agencies, EPA, and
DOT for the following:
    (i) Evaluating and choosing a model (or models) and associated
methods and assumptions to be used in hot-spot analyses and regional
emissions analyses;
    (ii) Determining which minor arterials and other transportation
projects should be considered ``regionally significant'' for the
purposes of regional emissions analysis (in addition to those
functionally classified as principal arterial or higher or fixed
guideway systems or extensions that offer an alternative to regional
highway travel), and which projects should be considered to have a
significant change in design concept and scope from the transportation
plan or TIP;
    (iii) Evaluating whether projects otherwise exempted from meeting
the requirements of this subpart (see Secs. 93.126 and 93.127) should
be treated as non-exempt in cases where potential adverse emissions
impacts may exist for any reason;
    (iv) Making a determination, as required by Sec. 93.113(c)(1),
whether past obstacles to implementation of TCMs which are behind the
schedule established in the applicable implementation plan have been
identified and are being overcome, and whether State and local agencies
with influence over approvals or funding for TCMs are giving maximum
priority to approval or funding for TCMs. This process shall also
consider whether delays in TCM implementation necessitate revisions to
the applicable implementation plan to remove TCMs or substitute TCMs or
other emission reduction measures;
    (v) Identifying, as required by Sec. 93.123(b), projects located at
sites in PM10 nonattainment areas which have vehicle and
roadway emission and dispersion characteristics which are essentially
identical to those at sites which have violations verified by
monitoring, and therefore require quantitative PM10 hot-spot
analysis;
    (vi) Notification of transportation plan or TIP revisions or
amendments which merely add or delete exempt projects listed in
Sec. 93.126 or Sec. 93.127; and
    (vii) Choosing conformity tests and methodologies for isolated
rural nonattainment and maintenance areas, as required by
Sec. 93.109(g)(2)(iii).
    (2) A process involving the MPO and State and local air quality
planning agencies and transportation agencies for the following:
    (i) Evaluating events which will trigger new conformity
determinations in addition to those triggering events established in
Sec. 93.104; and
    (ii) Consulting on emissions analysis for transportation activities
which cross the borders of MPOs or nonattainment areas or air basins.
    (3) Where the metropolitan planning area does not include the
entire nonattainment or maintenance area, a process involving the MPO
and the State department of transportation for cooperative planning and
analysis for purposes of determining conformity of all projects outside
the metropolitan area and within the nonattainment or maintenance area.
    (4) A process to ensure that plans for construction of regionally
significant projects which are not FHWA/FTA projects (including
projects for which alternative locations, design concept and scope, or
the no-build option are still being considered), including those by
recipients of funds designated under title 23 U.S.C. or the Federal
Transit Laws, are disclosed to the MPO on a regular basis, and to
ensure that any changes to those plans are immediately disclosed.
    (5) A process involving the MPO and other recipients of funds
designated under title 23 U.S.C. or the Federal Transit Laws for
assuming the location and design concept and scope of projects which
are disclosed to the MPO as required by paragraph (c)(4) of this
section but whose sponsors have not yet decided these features, in
sufficient detail to perform the regional emissions analysis according
to the requirements of Sec. 93.122.
    (6) A process for consulting on the design, schedule, and funding
of research and data collection efforts and regional transportation
model development by the MPO (e.g., household/ travel transportation
surveys).
    (7) A process for providing final documents (including applicable
implementation plans and implementation plan revisions) and supporting
information to each agency after approval or adoption. This process is
applicable to all agencies described in paragraph (a)(1) of this
section, including Federal agencies.
    (d) Resolving conflicts. Conflicts among State agencies or between
State agencies and an MPO shall be escalated to the Governor if they
cannot be resolved by the heads of the involved agencies. The State air
agency has 14

[[Page 43806]]

calendar days to appeal to the Governor after the State DOT or MPO has
notified the State air agency head of the resolution of his or her
comments. The implementation plan revision required by Sec. 51.390 of
this chapter shall define the procedures for starting the 14-day clock.
If the State air agency appeals to the Governor, the final conformity
determination must have the concurrence of the Governor. If the State
air agency does not appeal to the Governor within 14 days, the MPO or
State department of transportation may proceed with the final
conformity determination. The Governor may delegate his or her role in
this process, but not to the head or staff of the State or local air
agency, State department of transportation, State transportation
commission or board, or an MPO.
    (e) Public consultation procedures. Affected agencies making
conformity determinations on transportation plans, programs, and
projects shall establish a proactive public involvement process which
provides opportunity for public review and comment by, at a minimum,
providing reasonable public access to technical and policy information
considered by the agency at the beginning of the public comment period
and prior to taking formal action on a conformity determination for all
transportation plans and TIPs, consistent with these requirements and
those of 23 CFR 450.316(b). Any charges imposed for public inspection
and copying should be consistent with the fee schedule contained in 49
CFR 7.95. In addition, these agencies must specifically address in
writing all public comments that known plans for a regionally
significant project which is not receiving FHWA or FTA funding or
approval have not been properly reflected in the emissions analysis
supporting a proposed conformity finding for a transportation plan or
TIP. These agencies shall also provide opportunity for public
involvement in conformity determinations for projects where otherwise
required by law.

Sec. 93.106  Content of transportation plans.

    (a) Transportation plans adopted after January 1, 1997 in serious,
severe, or extreme ozone nonattainment areas and in serious CO
nonattainment areas. If the metropolitan planning area contains an
urbanized area population greater than 200,000, the transportation plan
must specifically describe the transportation system envisioned for
certain future years which shall be called horizon years.
    (1) The agency or organization developing the transportation plan
may choose any years to be horizon years, subject to the following
restrictions:
    (i) Horizon years may be no more than 10 years apart;
    (ii) The first horizon year may be no more than 10 years from the
base year used to validate the transportation demand planning model;
    (iii) If the attainment year is in the time span of the
transportation plan, the attainment year must be a horizon year; and
    (iv) The last horizon year must be the last year of the
transportation plan's forecast period.
    (2) For these horizon years:
    (i) The transportation plan shall quantify and document the
demographic and employment factors influencing expected transportation
demand, including land use forecasts, in accordance with implementation
plan provisions and the consultation requirements specified by
Sec. 93.105;
    (ii) The highway and transit system shall be described in terms of
the regionally significant additions or modifications to the existing
transportation network which the transportation plan envisions to be
operational in the horizon years. Additions and modifications to the
highway network shall be sufficiently identified to indicate
intersections with existing regionally significant facilities, and to
determine their effect on route options between transportation analysis
zones. Each added or modified highway segment shall also be
sufficiently identified in terms of its design concept and design scope
to allow modeling of travel times under various traffic volumes,
consistent with the modeling methods for area-wide transportation
analysis in use by the MPO. Transit facilities, equipment, and services
envisioned for the future shall be identified in terms of design
concept, design scope, and operating policies that are sufficient for
modeling of their transit ridership. Additions and modifications to the
transportation network shall be described sufficiently to show that
there is a reasonable relationship between expected land use and the
envisioned transportation system; and
    (iii) Other future transportation policies, requirements, services,
and activities, including intermodal activities, shall be described.
    (b) Moderate areas reclassified to serious. Ozone or CO
nonattainment areas which are reclassified from moderate to serious and
have an urbanized population greater than 200,000 must meet the
requirements of paragraph (a) of this section within two years from the
date of reclassification.
    (c) Transportation plans for other areas. Transportation plans for
other areas must meet the requirements of paragraph (a) of this section
at least to the extent it has been the previous practice of the MPO to
prepare plans which meet those requirements. Otherwise, the
transportation system envisioned for the future must be sufficiently
described within the transportation plans so that a conformity
determination can be made according to the criteria and procedures of
Secs. 93.109 through 93.119.
    (d) Savings. The requirements of this section supplement other
requirements of applicable law or regulation governing the format or
content of transportation plans.

Sec. 93.107  Relationship of transportation plan and TIP conformity
with the NEPA process.

    The degree of specificity required in the transportation plan and
the specific travel network assumed for air quality modeling do not
preclude the consideration of alternatives in the NEPA process or other
project development studies. Should the NEPA process result in a
project with design concept and scope significantly different from that
in the transportation plan or TIP, the project must meet the criteria
in Secs. 93.109 through 93.119 for projects not from a TIP before NEPA
process completion.

Sec. 93.108  Fiscal constraints for transportation plans and TIPs.

    Transportation plans and TIPs must be fiscally constrained
consistent with DOT's metropolitan planning regulations at 23 CFR part
450 in order to be found in conformity.

Sec. 93.109  Criteria and procedures for determining conformity of
transportation plans, programs, and projects: General.

    (a) In order for each transportation plan, program, and FHWA/FTA
project to be found to conform, the MPO and DOT must demonstrate that
the applicable criteria and procedures in this subpart are satisfied,
and the MPO and DOT must comply with all applicable conformity
requirements of implementation plans and of court orders for the area
which pertain specifically to conformity. The criteria for making
conformity determinations differ based on the action under review
(transportation plans, TIPs, and FHWA/FTA projects), the relevant
pollutant(s), and the status of the implementation plan.
    (b) Table 1 in this paragraph indicates the criteria and procedures
in Secs. 93.110 through 93.119 which apply for transportation plans,
TIPs, and FHWA/

[[Page 43807]]

FTA projects. Paragraphs (c) through (f) of this section explain when
the budget, emission reduction, and hot spot tests are required for
each pollutant. Paragraph (g) of this section addresses isolated rural
nonattainment and maintenance areas. Table 1 follows:

                      Table 1.--Conformity Criteria
------------------------------------------------------------------------

------------------------------------------------------------------------
All Actions at all times:
  Sec.  93.110                        Latest planning assumptions.
  Sec.  93.111                        Latest emissions model.
  Sec.  93.112                        Consultation.
Transportation Plan:
  Sec.  93.113(b)                     TCMs.
  Sec.  93.118 or Sec.  93.119        Emissions budget or Emission
                                       reduction.
TIP:
  Sec.  93.113(c)                     TCMs.
  Sec.  93.118 or Sec.  93.119        Emissions budget or Emission
                                       reduction.
Project (From a Conforming Plan and
 TIP):
  Sec.  93.114                        Currently conforming plan and TIP.
  Sec.  93.115                        Project from a conforming plan and
                                       TIP.
  Sec.  93.116                        CO and PM10 hot spots.
  Sec.  93.117                        PM10 control measures.
Project (Not From a Conforming Plan
 and TIP):
  Sec.  93.113(d)                     TCMs.
  Sec.  93.114                        Currently conforming plan and TIP.
  Sec.  93.116                        CO and PM10 hot spots.
  Sec.  93.117                        PM10 control measures.
  Sec.  93.118 or Sec.  93.119        Emissions budget or Emission
                                       reduction.
------------------------------------------------------------------------

    (c) Ozone nonattainment and maintenance areas. In addition to the
criteria listed in Table 1 in paragraph (b) of this section that are
required to be satisfied at all times, in ozone nonattainment and
maintenance areas conformity determinations must include a
demonstration that the budget and/or emission reduction tests are
satisfied as described in the following:
    (1) In ozone nonattainment and maintenance areas the budget test
must be satisfied as required by Sec. 93.118 for conformity
determinations made:
    (i) 45 days after a control strategy implementation plan revision
or maintenance plan has been submitted to EPA, unless EPA has declared
the motor vehicle emissions budget inadequate for transportation
conformity purposes; or
    (ii) After EPA has declared that the motor vehicle emissions budget
in a submitted control strategy implementation plan revision or
maintenance plan is adequate for transportation conformity purposes.
    (2) In ozone nonattainment areas that are required to submit a
control strategy implementation plan revision (usually moderate and
above areas), the emission reduction tests must be satisfied as
required by Sec. 93.119 for conformity determinations made:
    (i) During the first 45 days after a control strategy
implementation plan revision or maintenance plan has been submitted to
EPA, unless EPA has declared a motor vehicle emissions budget adequate
for transportation conformity purposes; or
    (ii) If EPA has declared the motor vehicle emissions budget in a
submitted control strategy implementation plan revision or maintenance
plan inadequate for transportation conformity purposes, and there is no
previously established motor vehicle emissions budget in the approved
implementation plan or a previously submitted control strategy
implementation plan revision or maintenance plan.
    (3) An ozone nonattainment area must satisfy the emission reduction
test for NOX, as required by Sec. 93.119, if the
implementation plan or plan submission that is applicable for the
purposes of conformity determinations is a 15% plan or Phase I
attainment demonstration that does not include a motor vehicle
emissions budget for NOX. The implementation plan will be
considered to establish a motor vehicle emissions budget for
NOX if the implementation plan or plan submission contains
an explicit NOX motor vehicle emissions budget that is
intended to act as a ceiling on future NOX emissions, and
the NOX motor vehicle emissions budget is a net reduction
from NOX emissions levels in 1990.
    (4) Ozone nonattainment areas that have not submitted a maintenance
plan and that are not required to submit a control strategy
implementation plan revision (usually marginal and below areas) must
satisfy one of the following requirements:
    (i) The emission reduction tests required by Sec. 93.119; or
    (ii) The State shall submit to EPA an implementation plan revision
that contains motor vehicle emissions budget(s) and an attainment
demonstration, and the budget test required by Sec. 93.118 must be
satisfied using the submitted motor vehicle emissions budget(s) (as
described in paragraph (c)(1) of this section).
    (5) Notwithstanding paragraphs (c)(1) and (c)(2) of this section,
moderate and above ozone nonattainment areas with three years of clean
data that have not submitted a maintenance plan and that EPA has
determined are not subject to the Clean Air Act reasonable further
progress and attainment demonstration requirements must satisfy one of
the following requirements:
    (i) The emission reduction tests as required by Sec. 93.119;
    (ii) The budget test as required by Sec. 93.118, using the motor
vehicle emissions budgets in the submitted control strategy
implementation plan (subject to the timing requirements of paragraph
(c)(1) of this section); or
    (iii) The budget test as required by Sec. 93.118, using the motor
vehicle emissions of ozone precursors in the most recent year of clean
data as motor vehicle emissions budgets, if such budgets are
established by the EPA rulemaking that determines that the area has
clean data.
    (d) CO nonattainment and maintenance areas. In addition to the
criteria listed in Table 1 in paragraph (b) of this section that are
required to be satisfied at all times, in CO nonattainment and
maintenance areas conformity determinations must include a
demonstration that the hot spot, budget and/or emission reduction tests
are satisfied as described in the following:
    (1) FHWA/FTA projects in CO nonattainment or maintenance areas must
satisfy the hot spot test required by Sec. 93.116(a) at all times.
Until a CO attainment demonstration or maintenance plan is approved by
EPA, FHWA/FTA projects must also satisfy the hot spot test required by
Sec. 93.116(b).
    (2) In CO nonattainment and maintenance areas the budget test must
be satisfied as required by Sec. 93.118 for conformity determinations
made:
    (i) 45 days after a control strategy implementation plan revision
or maintenance plan has been submitted to EPA, unless EPA has declared
the motor vehicle emissions budget inadequate for transportation
conformity purposes; or
    (ii) After EPA has declared that the motor vehicle emissions budget
in a submitted control strategy implementation plan revision or
maintenance plan is adequate for transportation conformity purposes.
    (3) Except as provided in paragraph (d)(4) of this section, in CO
nonattainment areas the emission reduction tests must be satisfied as
required by Sec. 93.119 for conformity determinations made:
    (i) During the first 45 days after a control strategy
implementation plan revision or maintenance plan has been submitted to
EPA, unless EPA has declared a motor vehicle emissions

[[Page 43808]]

budget adequate for transportation conformity purposes; or
    (ii) If EPA has declared the motor vehicle emissions budget in a
submitted control strategy implementation plan revision or maintenance
plan inadequate for transportation conformity purposes, and there is no
previously established motor vehicle emissions budget in the approved
implementation plan or a previously submitted control strategy
implementation plan revision or maintenance plan.
    (4) CO nonattainment areas that have not submitted a maintenance
plan and that are not required to submit an attainment demonstration
(e.g., moderate CO areas with a design value of 12.7 ppm or less or not
classified CO areas) must satisfy one of the following requirements:
    (i) The emission reduction tests required by Sec. 93.119; or
    (ii) The State shall submit to EPA an implementation plan revision
that contains motor vehicle emissions budget(s) and an attainment
demonstration, and the budget test required by Sec. 93.118 must be
satisfied using the submitted motor vehicle emissions budget(s) (as
described in paragraph (d)(2) of this section).
    (e) PM10 nonattainment and maintenance areas. In
addition to the criteria listed in Table 1 in paragraph (b) of this
section that are required to be satisfied at all times, in
PM10 nonattainment and maintenance areas conformity
determinations must include a demonstration that the hot spot, budget
and/or emission reduction tests are satisfied as described in the
following:
    (1) FHWA/FTA projects in PM10 nonattainment or
maintenance areas must satisfy the hot spot test required by
Sec. 93.116(a).
    (2) In PM10 nonattainment and maintenance areas the
budget test must be satisfied as required by Sec. 93.118 for conformity
determinations made:
    (i) 45 days after a control strategy implementation plan revision
or maintenance plan has been submitted to EPA, unless EPA has declared
the motor vehicle emissions budget inadequate for transportation
conformity purposes; or
    (ii) After EPA has declared that the motor vehicle emissions budget
in a submitted control strategy implementation plan revision or
maintenance plan is adequate for transportation conformity purposes.
    (3) In PM10 nonattainment areas the emission reduction
tests must be satisfied as required by Sec. 93.119 for conformity
determinations made:
    (i) During the first 45 days after a control strategy
implementation plan revision or maintenance plan has been submitted to
EPA, unless EPA has declared a motor vehicle emissions budget adequate
for transportation conformity purposes;
    (ii) If EPA has declared the motor vehicle emissions budget in a
submitted control strategy implementation plan revision or maintenance
plan inadequate for transportation conformity purposes, and there is no
previously established motor vehicle emissions budget in the approved
implementation plan or a previously submitted control strategy
implementation plan revision or maintenance plan; or
    (iii) If the submitted implementation plan revision is a
demonstration of impracticability under CAA section 189(a)(1)(B)(ii)
and does not demonstrate attainment.
    (f) NO2 nonattainment and maintenance areas. In addition
to the criteria listed in Table 1 in paragraph (b) of this section that
are required to be satisfied at all times, in NO2
nonattainment and maintenance areas conformity determinations must
include a demonstration that the budget and/or emission reduction tests
are satisfied as described in the following:
    (1) In NO2 nonattainment and maintenance areas the
budget test must be satisfied as required by Sec. 93.118 for conformity
determinations made:
    (i) 45 days after a control strategy implementation plan revision
or maintenance plan has been submitted to EPA, unless EPA has declared
the motor vehicle emissions budget inadequate for transportation
conformity purposes; or
    (ii) After EPA has declared that the motor vehicle emissions budget
in a submitted control strategy implementation plan revision or
maintenance plan is adequate for transportation conformity purposes.
    (2) In NO2 nonattainment areas the emission reduction
tests must be satisfied as required by Sec. 93.119 for conformity
determinations made:
    (i) During the first 45 days after a control strategy
implementation plan revision or maintenance plan has been submitted to
EPA, unless EPA has declared a motor vehicle emissions budget adequate
for transportation conformity purposes; or
    (ii) If EPA has declared the motor vehicle emissions budget in a
submitted control strategy implementation plan revision or maintenance
plan inadequate for transportation conformity purposes, and there is no
previously established motor vehicle emissions budget in the approved
implementation plan or a previously submitted control strategy
implementation plan revision or maintenance plan.
    (g) Isolated rural nonattainment and maintenance areas. This
paragraph applies to any nonattainment or maintenance area (or portion
thereof) which does not have a metropolitan transportation plan or TIP
and whose projects are not part of the emissions analysis of any MPO's
metropolitan transportation plan or TIP. This paragraph does not apply
to ``donut'' areas which are outside the metropolitan planning boundary
and inside the nonattainment/maintenance area boundary.
    (1) FHWA/FTA projects in all isolated rural nonattainment and
maintenance areas must satisfy the requirements of Secs. 93.110,
93.111, 93.112, 93.113(d), 93.116, and 93.117. Until EPA approves the
control strategy implementation plan or maintenance plan for a rural CO
nonattainment or maintenance area, FHWA/FTA projects must also satisfy
the requirements of Sec. 93.116(b) (``Localized CO and PM10
violations (hot spots)'').
    (2) Isolated rural nonattainment and maintenance areas are subject
to the budget and/or emission reduction tests as described in
paragraphs (c) through (f) of this section, with the following
modifications:
    (i) When the requirements of Secs. 93.118 and 93.119 apply to
isolated rural nonattainment and maintenance areas, references to
``transportation plan'' or ``TIP'' should be taken to mean those
projects in the statewide transportation plan or statewide TIP which
are in the rural nonattainment or maintenance area.
    (ii) In isolated rural nonattainment and maintenance areas that are
subject to Sec. 93.118, FHWA/FTA projects must be consistent with motor
vehicle emissions budget(s) for the years in the timeframe of the
attainment demonstration or maintenance plan. For years after the
attainment year (if a maintenance plan has not been submitted) or after
the last year of the maintenance plan, FHWA/FTA projects must satisfy
one of the following requirements:
    (A) Sec. 93.118;
    (B) Sec. 93.119 (including regional emissions analysis for
NOX in all ozone nonattainment and maintenance areas,
notwithstanding Sec. 93.119(d)(2)); or
    (C) As demonstrated by the air quality dispersion model or other
air quality modeling technique used in the attainment demonstration or
maintenance plan, the FHWA/FTA project, in combination with all other

[[Page 43809]]

regionally significant projects expected in the area in the timeframe
of the statewide transportation plan, must not cause or contribute to
any new violation of any standard in any areas; increase the frequency
or severity of any existing violation of any standard in any area; or
delay timely attainment of any standard or any required interim
emission reductions or other milestones in any area. Control measures
assumed in the analysis must be enforceable.
    (iii) The choice of requirements in paragraph (g)(2)(ii) of this
section and the methodology used to meet the requirements of paragraph
(g)(2)(ii)(C) of this section must be determined through the
interagency consultation process required in Sec. 93.105(c)(1)(vii)
through which the relevant recipients of title 23 U.S.C. or Federal
Transit Laws funds, the local air quality agency, the State air quality
agency, and the State department of transportation should reach
consensus about the option and methodology selected. EPA and DOT must
be consulted through this process as well. In the event of unresolved
disputes, conflicts may be escalated to the Governor consistent with
the procedure in Sec. 93.105(d), which applies for any State air agency
comments on a conformity determination.

Sec. 93.110  Criteria and procedures: Latest planning assumptions.

    (a) The conformity determination, with respect to all other
applicable criteria in Secs. 93.111 through 93.119, must be based upon
the most recent planning assumptions in force at the time of the
conformity determination. The conformity determination must satisfy the
requirements of paragraphs (b) through (f) of this section.
    (b) Assumptions must be derived from the estimates of current and
future population, employment, travel, and congestion most recently
developed by the MPO or other agency authorized to make such estimates
and approved by the MPO. The conformity determination must also be
based on the latest assumptions about current and future background
concentrations.
    (c) The conformity determination for each transportation plan and
TIP must discuss how transit operating policies (including fares and
service levels) and assumed transit ridership have changed since the
previous conformity determination.
    (d) The conformity determination must include reasonable
assumptions about transit service and increases in transit fares and
road and bridge tolls over time.
    (e) The conformity determination must use the latest existing
information regarding the effectiveness of the TCMs and other
implementation plan measures which have already been implemented.
    (f) Key assumptions shall be specified and included in the draft
documents and supporting materials used for the interagency and public
consultation required by Sec. 93.105.

Sec. 93.111  Criteria and procedures: Latest emissions model.

    (a) The conformity determination must be based on the latest
emission estimation model available. This criterion is satisfied if the
most current version of the motor vehicle emissions model specified by
EPA for use in the preparation or revision of implementation plans in
that State or area is used for the conformity analysis. Where EMFAC is
the motor vehicle emissions model used in preparing or revising the
applicable implementation plan, new versions must be approved by EPA
before they are used in the conformity analysis.
    (b) EPA will consult with DOT to establish a grace period following
the specification of any new model.
    (1) The grace period will be no less than three months and no more
than 24 months after notice of availability is published in the Federal
Register.
    (2) The length of the grace period will depend on the degree of
change in the model and the scope of re-planning likely to be necessary
by MPOs in order to assure conformity. If the grace period will be
longer than three months, EPA will announce the appropriate grace
period in the Federal Register.
    (c) Transportation plan and TIP conformity analyses for which the
emissions analysis was begun during the grace period or before the
Federal Register notice of availability of the latest emission model
may continue to use the previous version of the model. Conformity
determinations for projects may also be based on the previous model if
the analysis was begun during the grace period or before the Federal
Register notice of availability, and if the final environmental
document for the project is issued no more than three years after the
issuance of the draft environmental document.

Sec. 93.112  Criteria and procedures: Consultation.

    Conformity must be determined according to the consultation
procedures in this subpart and in the applicable implementation plan,
and according to the public involvement procedures established in
compliance with 23 CFR part 450. Until the implementation plan revision
required by Sec. 51.390 of this chapter is fully approved by EPA, the
conformity determination must be made according to Sec. 93.105 (a)(2)
and (e) and the requirements of 23 CFR part 450.

Sec. 93.113  Criteria and procedures: Timely implementation of TCMs.

    (a) The transportation plan, TIP, or any FHWA/FTA project which is
not from a conforming plan and TIP must provide for the timely
implementation of TCMs from the applicable implementation plan.
    (b) For transportation plans, this criterion is satisfied if the
following two conditions are met:
    (1) The transportation plan, in describing the envisioned future
transportation system, provides for the timely completion or
implementation of all TCMs in the applicable implementation plan which
are eligible for funding under title 23 U.S.C. or the Federal Transit
Laws, consistent with schedules included in the applicable
implementation plan.
    (2) Nothing in the transportation plan interferes with the
implementation of any TCM in the applicable implementation plan.
    (c) For TIPs, this criterion is satisfied if the following
conditions are met:
    (1) An examination of the specific steps and funding source(s)
needed to fully implement each TCM indicates that TCMs which are
eligible for funding under title 23 U.S.C. or the Federal Transit Laws
are on or ahead of the schedule established in the applicable
implementation plan, or, if such TCMs are behind the schedule
established in the applicable implementation plan, the MPO and DOT have
determined that past obstacles to implementation of the TCMs have been
identified and have been or are being overcome, and that all State and
local agencies with influence over approvals or funding for TCMs are
giving maximum priority to approval or funding of TCMs over other
projects within their control, including projects in locations outside
the nonattainment or maintenance area.
    (2) If TCMs in the applicable implementation plan have previously
been programmed for Federal funding but the funds have not been
obligated and the TCMs are behind the schedule in the implementation
plan, then the TIP cannot be found to conform if the funds intended for
those TCMs are reallocated to projects in the TIP other than TCMs, or
if there are no other TCMs in the TIP, if the funds are reallocated to
projects in the TIP other than projects which are eligible for Federal
funding intended for air quality

[[Page 43810]]

improvement projects, e.g., the Congestion Mitigation and Air Quality
Improvement Program.
    (3) Nothing in the TIP may interfere with the implementation of any
TCM in the applicable implementation plan.
    (d) For FHWA/FTA projects which are not from a conforming
transportation plan and TIP, this criterion is satisfied if the project
does not interfere with the implementation of any TCM in the applicable
implementation plan.

Sec. 93.114  Criteria and procedures: Currently conforming
transportation plan and TIP.

    There must be a currently conforming transportation plan and
currently conforming TIP at the time of project approval.
    (a) Only one conforming transportation plan or TIP may exist in an
area at any time; conformity determinations of a previous
transportation plan or TIP expire once the current plan or TIP is found
to conform by DOT. The conformity determination on a transportation
plan or TIP will also lapse if conformity is not determined according
to the frequency requirements specified in Sec. 93.104.
    (b) This criterion is not required to be satisfied at the time of
project approval for a TCM specifically included in the applicable
implementation plan, provided that all other relevant criteria of this
subpart are satisfied.

Sec. 93.115  Criteria and procedures: Projects from a plan and TIP.

    (a) The project must come from a conforming plan and program. If
this criterion is not satisfied, the project must satisfy all criteria
in Table 1 of Sec. 93.109(b) for a project not from a conforming
transportation plan and TIP. A project is considered to be from a
conforming transportation plan if it meets the requirements of
paragraph (b) of this section and from a conforming program if it meets
the requirements of paragraph (c) of this section. Special provisions
for TCMs in an applicable implementation plan are provided in paragraph
(d) of this section.
    (b) A project is considered to be from a conforming transportation
plan if one of the following conditions applies:
    (1) For projects which are required to be identified in the
transportation plan in order to satisfy Sec. 93.106 (``Content of
transportation plans''), the project is specifically included in the
conforming transportation plan and the project's design concept and
scope have not changed significantly from those which were described in
the transportation plan, or in a manner which would significantly
impact use of the facility; or
    (2) For projects which are not required to be specifically
identified in the transportation plan, the project is identified in the
conforming transportation plan, or is consistent with the policies and
purpose of the transportation plan and will not interfere with other
projects specifically included in the transportation plan.
    (c) A project is considered to be from a conforming program if the
following conditions are met:
    (1) The project is included in the conforming TIP and the design
concept and scope of the project were adequate at the time of the TIP
conformity determination to determine its contribution to the TIP's
regional emissions, and the project design concept and scope have not
changed significantly from those which were described in the TIP; and
    (2) If the TIP describes a project design concept and scope which
includes project-level emissions mitigation or control measures,
written commitments to implement such measures must be obtained from
the project sponsor and/or operator as required by Sec. 93.125(a) in
order for the project to be considered from a conforming program. Any
change in these mitigation or control measures that would significantly
reduce their effectiveness constitutes a change in the design concept
and scope of the project.
    (d) TCMs. This criterion is not required to be satisfied for TCMs
specifically included in an applicable implementation plan.

Sec. 93.116  Criteria and procedures: Localized CO and PM10
violations (hot spots).

    (a) This paragraph applies at all times. The FHWA/FTA project must
not cause or contribute to any new localized CO or PM10
violations or increase the frequency or severity of any existing CO or
PM10 violations in CO and PM10 nonattainment and
maintenance areas. This criterion is satisfied if it is demonstrated
that no new local violations will be created and the severity or number
of existing violations will not be increased as a result of the
project. The demonstration must be performed according to the
consultation requirements of Sec. 93.105(c)(1)(i) and the methodology
requirements of Sec. 93.123.
    (b) This paragraph applies for CO nonattainment areas as described
in Sec. 93.109(d)(1). Each FHWA/FTA project must eliminate or reduce
the severity and number of localized CO violations in the area
substantially affected by the project (in CO nonattainment areas). This
criterion is satisfied with respect to existing localized CO violations
if it is demonstrated that existing localized CO violations will be
eliminated or reduced in severity and number as a result of the
project. The demonstration must be performed according to the
consultation requirements of Sec. 93.105(c)(1)(i) and the methodology
requirements of Sec. 93.123.

Sec. 93.117  Criteria and procedures: Compliance with PM10
control measures.

    The FHWA/FTA project must comply with PM10 control
measures in the applicable implementation plan. This criterion is
satisfied if the project-level conformity determination contains a
written commitment from the project sponsor to include in the final
plans, specifications, and estimates for the project those control
measures (for the purpose of limiting PM10 emissions from
the construction activities and/or normal use and operation associated
with the project) that are contained in the applicable implementation
plan.

Sec. 93.118  Criteria and procedures: Motor vehicle emissions budget.

    (a) The transportation plan, TIP, and project not from a conforming
transportation plan and TIP must be consistent with the motor vehicle
emissions budget(s) in the applicable implementation plan (or
implementation plan submission). This criterion applies as described in
Sec. 93.109(c) through (g). This criterion is satisfied if it is
demonstrated that emissions of the pollutants or pollutant precursors
described in paragraph (c) of this section are less than or equal to
the motor vehicle emissions budget(s) established in the applicable
implementation plan or implementation plan submission.
    (b) Consistency with the motor vehicle emissions budget(s) must be
demonstrated for each year for which the applicable (and/or submitted)
implementation plan specifically establishes motor vehicle emissions
budget(s), for the last year of the transportation plan's forecast
period, and for any intermediate years as necessary so that the years
for which consistency is demonstrated are no more than ten years apart,
as follows:
    (1) Until a maintenance plan is submitted:
    (i) Emissions in each year (such as milestone years and the
attainment year) for which the control strategy implementation plan
revision establishes motor vehicle emissions budget(s) must be less
than or equal to that year's motor vehicle emissions budget(s); and

[[Page 43811]]

    (ii) Emissions in years for which no motor vehicle emissions
budget(s) are specifically established must be less than or equal to
the motor vehicle emissions budget(s) established for the most recent
prior year. For example, emissions in years after the attainment year
for which the implementation plan does not establish a budget must be
less than or equal to the motor vehicle emissions budget(s) for the
attainment year.
    (2) When a maintenance plan has been submitted:
    (i) Emissions must be less than or equal to the motor vehicle
emissions budget(s) established for the last year of the maintenance
plan, and for any other years for which the maintenance plan
establishes motor vehicle emissions budgets. If the maintenance plan
does not establish motor vehicle emissions budgets for any years other
than the last year of the maintenance plan, the demonstration of
consistency with the motor vehicle emissions budget(s) must be
accompanied by a qualitative finding that there are no factors which
would cause or contribute to a new violation or exacerbate an existing
violation in the years before the last year of the maintenance plan.
The interagency consultation process required by Sec. 93.105 shall
determine what must be considered in order to make such a finding;
    (ii) For years after the last year of the maintenance plan,
emissions must be less than or equal to the maintenance plan's motor
vehicle emissions budget(s) for the last year of the maintenance plan;
and
    (iii) If an approved control strategy implementation plan has
established motor vehicle emissions budgets for years in the timeframe
of the transportation plan, emissions in these years must be less than
or equal to the control strategy implementation plan's motor vehicle
emissions budget(s) for these years.
    (c) Consistency with the motor vehicle emissions budget(s) must be
demonstrated for each pollutant or pollutant precursor in
Sec. 93.102(b) for which the area is in nonattainment or maintenance
and for which the applicable implementation plan (or implementation
plan submission) establishes a motor vehicle emissions budget.
    (d) Consistency with the motor vehicle emissions budget(s) must be
demonstrated by including emissions from the entire transportation
system, including all regionally significant projects contained in the
transportation plan and all other regionally significant highway and
transit projects expected in the nonattainment or maintenance area in
the timeframe of the transportation plan.
    (1) Consistency with the motor vehicle emissions budget(s) must be
demonstrated with a regional emissions analysis that meets the
requirements of Secs. 93.122 and 93.105(c)(1)(i).
    (2) The regional emissions analysis may be performed for any years
in the timeframe of the transportation plan provided they are not more
than ten years apart and provided the analysis is performed for the
attainment year (if it is in the timeframe of the transportation plan)
and the last year of the plan's forecast period. Emissions in years for
which consistency with motor vehicle emissions budgets must be
demonstrated, as required in paragraph (b) of this section, may be
determined by interpolating between the years for which the regional
emissions analysis is performed.
    (e) Motor vehicle emissions budgets in submitted control strategy
implementation plan revisions and submitted maintenance plans. (1)
Consistency with the motor vehicle emissions budgets in submitted
control strategy implementation plan revisions or maintenance plans
must be demonstrated if EPA has declared the motor vehicle emissions
budget(s) adequate for transportation conformity purposes, or beginning
45 days after the control strategy implementation plan revision or
maintenance plan has been submitted (unless EPA has declared the motor
vehicle emissions budget(s) inadequate for transportation conformity
purposes). However, submitted implementation plans do not supersede the
motor vehicle emissions budgets in approved implementation plans for
the period of years addressed by the approved implementation plan.
    (2) If EPA has declared an implementation plan submission's motor
vehicle emissions budget(s) inadequate for transportation conformity
purposes, the inadequate budget(s) shall not be used to satisfy the
requirements of this section. Consistency with the previously
established motor vehicle emissions budget(s) must be demonstrated. If
there are no previous approved implementation plans or implementation
plan submissions with motor vehicle emissions budgets, the emission
reduction tests required by Sec. 93.119 must be satisfied.
    (3) If EPA declares an implementation plan submission's motor
vehicle emissions budget(s) inadequate for transportation conformity
purposes more than 45 days after its submission to EPA, and conformity
of a transportation plan or TIP has already been determined by DOT
using the budget(s), the conformity determination will remain valid.
Projects included in that transportation plan or TIP could still
satisfy Secs. 93.114 and 93.115, which require a currently conforming
transportation plan and TIP to be in place at the time of a project's
conformity determination and that projects come from a conforming
transportation plan and TIP.
    (4) EPA will not find a motor vehicle emissions budget in a
submitted control strategy implementation plan revision or maintenance
plan to be adequate for transportation conformity purposes unless the
following minimum criteria are satisfied:
    (i) The submitted control strategy implementation plan revision or
maintenance plan was endorsed by the Governor (or his or her designee)
and was subject to a State public hearing;
    (ii) Before the control strategy implementation plan or maintenance
plan was submitted to EPA, consultation among federal, State, and local
agencies occurred; full implementation plan documentation was provided
to EPA; and EPA's stated concerns, if any, were addressed;
    (iii) The motor vehicle emissions budget(s) is clearly identified
and precisely quantified;
    (iv) The motor vehicle emissions budget(s), when considered
together with all other emissions sources, is consistent with
applicable requirements for reasonable further progress, attainment, or
maintenance (whichever is relevant to the given implementation plan
submission);
    (v) The motor vehicle emissions budget(s) is consistent with and
clearly related to the emissions inventory and the control measures in
the submitted control strategy implementation plan revision or
maintenance plan; and
    (vi) Revisions to previously submitted control strategy
implementation plans or maintenance plans explain and document any
changes to previously submitted budgets and control measures; impacts
on point and area source emissions; any changes to established safety
margins (see Sec. 93.101 for definition); and reasons for the changes
(including the basis for any changes related to emission factors or
estimates of vehicle miles traveled).
    (5) Before determining the adequacy of a submitted motor vehicle
emissions budget, EPA will review the State's compilation of public
comments and response to comments that are required to be submitted
with any implementation plan. EPA will document its consideration of
such

[[Page 43812]]

comments and responses in a letter to the State indicating the adequacy
of the submitted motor vehicle emissions budget.
    (6) When the motor vehicle emissions budget(s) used to satisfy the
requirements of this section are established by an implementation plan
submittal that has not yet been approved or disapproved by EPA, the MPO
and DOT's conformity determinations will be deemed to be a statement
that the MPO and DOT are not aware of any information that would
indicate that emissions consistent with the motor vehicle emissions
budget will cause or contribute to any new violation of any standard;
increase the frequency or severity of any existing violation of any
standard; or delay timely attainment of any standard or any required
interim emission reductions or other milestones.

Sec. 93.119  Criteria and procedures: Emission reductions in areas
without motor vehicle emissions budgets.

    (a) The transportation plan, TIP, and project not from a conforming
transportation plan and TIP must contribute to emissions reductions.
This criterion applies as described in Sec. 93.109(c) through (g). It
applies to the net effect of the action (transportation plan, TIP, or
project not from a conforming transportation plan and TIP) on motor
vehicle emissions from the entire transportation system.
    (b) This criterion may be met in moderate and above ozone
nonattainment areas that are subject to the reasonable further progress
requirements of CAA section 182(b)(1) and in moderate with design value
greater than 12.7 ppm and serious CO nonattainment areas if a regional
emissions analysis that satisfies the requirements of Sec. 93.122 and
paragraphs (e) through (h) of this section demonstrates that for each
analysis year and for each of the pollutants described in paragraph (d)
of this section:
    (1) The emissions predicted in the ``Action'' scenario are less
than the emissions predicted in the ``Baseline'' scenario, and this can
be reasonably expected to be true in the periods between the analysis
years; and
    (2) The emissions predicted in the ``Action'' scenario are lower
than 1990 emissions by any nonzero amount.
    (c) This criterion may be met in PM10 and NO2
nonattainment areas; marginal and below ozone nonattainment areas and
other ozone nonattainment areas that are not subject to the reasonable
further progress requirements of CAA section 182(b)(1); and moderate
with design value less than 12.7 ppm and below CO nonattainment areas
if a regional emissions analysis that satisfies the requirements of
Sec. 93.122 and paragraphs (e) through (h) of this section demonstrates
that for each analysis year and for each of the pollutants described in
paragraph (d) of this section, one of the following requirements is
met:
    (1) The emissions predicted in the ``Action'' scenario are less
than the emissions predicted in the ``Baseline'' scenario, and this can
be reasonably expected to be true in the periods between the analysis
years; or
    (2) The emissions predicted in the ``Action'' scenario are not
greater than baseline emissions. Baseline emissions are those estimated
to have occurred during calendar year 1990, unless the conformity
implementation plan revision required by Sec. 51.390 of this chapter
defines the baseline emissions for a PM10 area to be those
occurring in a different calendar year for which a baseline emissions
inventory was developed for the purpose of developing a control
strategy implementation plan.
    (d) Pollutants. The regional emissions analysis must be performed
for the following pollutants:
    (1) VOC in ozone areas;
    (2) NOX in ozone areas, unless the EPA Administrator
determines that additional reductions of NOX would not
contribute to attainment;
    (3) CO in CO areas;
    (4) PM10 in PM10 areas;
    (5) Transportation-related precursors of PM10 in
PM10 nonattainment and maintenance areas if the EPA Regional
Administrator or the director of the State air agency has made a
finding that such precursor emissions from within the area are a
significant contributor to the PM10 nonattainment problem
and has so notified the MPO and DOT; and
    (6) NOX in NO2 areas.
    (e) Analysis years. The regional emissions analysis must be
performed for analysis years that are no more than ten years apart. The
first analysis year must be no more than five years beyond the year in
which the conformity determination is being made. The last year of
transportation plan's forecast period must also be an analysis year.
    (f) ``Baseline'' scenario. The regional emissions analysis required
by paragraphs (b) and (c) of this section must estimate the emissions
that would result from the ``Baseline'' scenario in each analysis year.
The ``Baseline'' scenario must be defined for each of the analysis
years. The ``Baseline'' scenario is the future transportation system
that will result from current programs, including the following (except
that exempt projects listed in Sec. 93.126 and projects exempt from
regional emissions analysis as listed in Sec. 93.127 need not be
explicitly considered):
    (1) All in-place regionally significant highway and transit
facilities, services and activities;
    (2) All ongoing travel demand management or transportation system
management activities; and
    (3) Completion of all regionally significant projects, regardless
of funding source, which are currently under construction or are
undergoing right-of-way acquisition (except for hardship acquisition
and protective buying); come from the first year of the previously
conforming transportation plan and/or TIP; or have completed the NEPA
process.
    (g) ``Action'' scenario. The regional emissions analysis required
by paragraphs (b) and (c) of this section must estimate the emissions
that would result from the ``Action'' scenario in each analysis year.
The ``Action'' scenario must be defined for each of the analysis years.
The ``Action'' scenario is the transportation system that would result
from the implementation of the proposed action (transportation plan,
TIP, or project not from a conforming transportation plan and TIP) and
all other expected regionally significant projects in the nonattainment
area. The ``Action'' scenario must include the following (except that
exempt projects listed in Sec. 93.126 and projects exempt from regional
emissions analysis as listed in Sec. 93.127 need not be explicitly
considered):
    (1) All facilities, services, and activities in the ``Baseline''
scenario;
    (2) Completion of all TCMs and regionally significant projects
(including facilities, services, and activities) specifically
identified in the proposed transportation plan which will be
operational or in effect in the analysis year, except that regulatory
TCMs may not be assumed to begin at a future time unless the regulation
is already adopted by the enforcing jurisdiction or the TCM is
identified in the applicable implementation plan;
    (3) All travel demand management programs and transportation system
management activities known to the MPO, but not included in the
applicable implementation plan or utilizing any Federal funding or
approval, which have been fully adopted and/or funded by the enforcing
jurisdiction or sponsoring agency since the last conformity
determination;
    (4) The incremental effects of any travel demand management
programs and transportation system management activities known to the
MPO, but not included in the applicable implementation plan or
utilizing any

[[Page 43813]]

Federal funding or approval, which were adopted and/or funded prior to
the date of the last conformity determination, but which have been
modified since then to be more stringent or effective;
    (5) Completion of all expected regionally significant highway and
transit projects which are not from a conforming transportation plan
and TIP; and
    (6) Completion of all expected regionally significant non-FHWA/FTA
highway and transit projects that have clear funding sources and
commitments leading toward their implementation and completion by the
analysis year.
    (h) Projects not from a conforming transportation plan and TIP. For
the regional emissions analysis required by paragraphs (b) and (c) of
this section, if the project which is not from a conforming
transportation plan and TIP is a modification of a project currently in
the plan or TIP, the 'Baseline' scenario must include the project with
its original design concept and scope, and the 'Action' scenario must
include the project with its new design concept and scope.

Sec. 93.120  Consequences of control strategy implementation plan
failures.

    (a) Disapprovals. (1) If EPA disapproves any submitted control
strategy implementation plan revision (with or without a protective
finding), the conformity status of the transportation plan and TIP
shall lapse on the date that highway sanctions as a result of the
disapproval are imposed on the nonattainment area under section
179(b)(1) of the CAA. No new transportation plan, TIP, or project may
be found to conform until another control strategy implementation plan
revision fulfilling the same CAA requirements is submitted and
conformity to this submission is determined.
    (2) If EPA disapproves a submitted control strategy implementation
plan revision without making a protective finding, then beginning 120
days after such disapproval, only projects in the first three years of
the currently conforming transportation plan and TIP may be found to
conform. This means that beginning 120 days after disapproval without a
protective finding, no transportation plan, TIP, or project not in the
first three years of the currently conforming plan and TIP may be found
to conform until another control strategy implementation plan revision
fulfilling the same CAA requirements is submitted and conformity to
this submission is determined. During the first 120 days following
EPA's disapproval without a protective finding, transportation plan,
TIP, and project conformity determinations shall be made using the
motor vehicle emissions budget(s) in the disapproved control strategy
implementation plan, unless another control strategy implementation
plan revision has been submitted and its motor vehicle emissions
budget(s) applies for transportation conformity purposes, pursuant to
Sec. 93.109.
    (3) In disapproving a control strategy implementation plan
revision, EPA would give a protective finding where a submitted plan
contains adopted control measures or written commitments to adopt
enforceable control measures that fully satisfy the emissions
reductions requirements relevant to the statutory provision for which
the implementation plan revision was submitted, such as reasonable
further progress or attainment.
    (b) Failure to submit and incompleteness. In areas where EPA
notifies the State, MPO, and DOT of the State's failure to submit a
control strategy implementation plan or submission of an incomplete
control strategy implementation plan revision (either of which
initiates the sanction process under CAA sections 179 or 110(m)), the
conformity status of the transportation plan and TIP shall lapse on the
date that highway sanctions are imposed on the nonattainment area for
such failure under section 179(b)(1) of the CAA, unless the failure has
been remedied and acknowledged by a letter from the EPA Regional
Administrator.
    (c) Federal implementation plans. If EPA promulgates a Federal
implementation plan that contains motor vehicle emissions budget(s) as
a result of a State failure, the conformity lapse imposed by this
section because of that State failure is removed.

Sec. 93.121  Requirements for adoption or approval of projects by other
recipients of funds designated under title 23 U.S.C. or the Federal
Transit Laws.

    (a) Except as provided in paragraph (b) of this section, no
recipient of Federal funds designated under title 23 U.S.C. or the
Federal Transit Laws shall adopt or approve a regionally significant
highway or transit project, regardless of funding source, unless the
recipient finds that the requirements of one of the following are met:
    (1) The project was included in the first three years of the most
recently conforming transportation plan and TIP (or the conformity
determination's regional emissions analyses), even if conformity status
is currently lapsed; and the project's design concept and scope has not
changed significantly from those analyses; or
    (2) There is a currently conforming transportation plan and TIP,
and a new regional emissions analysis including the project and the
currently conforming transportation plan and TIP demonstrates that the
transportation plan and TIP would still conform if the project were
implemented (consistent with the requirements of Secs. 93.118 and/or
93.119 for a project not from a conforming transportation plan and
TIP).
    (b) In isolated rural nonattainment and maintenance areas subject
to Sec. 93.109(g), no recipient of Federal funds designated under title
23 U.S.C. or the Federal Transit Laws shall adopt or approve a
regionally significant highway or transit project, regardless of
funding source, unless the recipient finds that the requirements of one
of the following are met:
    (1) The project was included in the regional emissions analysis
supporting the most recent conformity determination for the portion of
the statewide transportation plan and TIP which are in the
nonattainment or maintenance area, and the project's design concept and
scope has not changed significantly; or
    (2) A new regional emissions analysis including the project and all
other regionally significant projects expected in the nonattainment or
maintenance area demonstrates that those projects in the statewide
transportation plan and statewide TIP which are in the nonattainment or
maintenance area would still conform if the project were implemented
(consistent with the requirements of Secs. 93.118 and/or 93.119 for
projects not from a conforming transportation plan and TIP).

Sec. 93.122  Procedures for determining regional transportation-related
emissions.

    (a) General requirements. (1) The regional emissions analysis
required by Secs. 93.118 and 93.119 for the transportation plan, TIP,
or project not from a conforming plan and TIP must include all
regionally significant projects expected in the nonattainment or
maintenance area. The analysis shall include FHWA/FTA projects proposed
in the transportation plan and TIP and all other regionally significant
projects which are disclosed to the MPO as required by Sec. 93.105.
Projects which are not regionally significant are not required to be
explicitly modeled, but vehicle miles traveled (VMT) from such projects
must be estimated in accordance with reasonable professional practice.
The effects of TCMs and similar projects that are not regionally

[[Page 43814]]

significant may also be estimated in accordance with reasonable
professional practice.
    (2) The emissions analysis may not include for emissions reduction
credit any TCMs or other measures in the applicable implementation plan
which have been delayed beyond the scheduled date(s) until such time as
their implementation has been assured. If the measure has been
partially implemented and it can be demonstrated that it is providing
quantifiable emission reduction benefits, the emissions analysis may
include that emissions reduction credit.
    (3) Emissions reduction credit from projects, programs, or
activities which require a regulatory action in order to be implemented
may not be included in the emissions analysis unless:
    (i) The regulatory action is already adopted by the enforcing
jurisdiction;
    (ii) The project, program, or activity is included in the
applicable implementation plan;
    (iii) The control strategy implementation plan submission or
maintenance plan submission that establishes the motor vehicle
emissions budget(s) for the purposes of Sec. 93.118 contains a written
commitment to the project, program, or activity by the agency with
authority to implement it; or
    (iv) EPA has approved an opt-in to a Federally enforced program,
EPA has promulgated the program (if the control program is a Federal
responsibility, such as vehicle tailpipe standards), or the Clean Air
Act requires the program without need for individual State action and
without any discretionary authority for EPA to set its stringency,
delay its effective date, or not implement the program.
    (4) Emissions reduction credit from control measures that are not
included in the transportation plan and TIP and that do not require a
regulatory action in order to be implemented may not be included in the
emissions analysis unless the conformity determination includes written
commitments to implementation from the appropriate entities.
    (i) Persons or entities voluntarily committing to control measures
must comply with the obligations of such commitments.
    (ii) The conformity implementation plan revision required in
Sec. 51.390 of this chapter must provide that written commitments to
control measures that are not included in the transportation plan and
TIP must be obtained prior to a conformity determination and that such
commitments must be fulfilled.
    (5) A regional emissions analysis for the purpose of satisfying the
requirements of Sec. 93.119 must make the same assumptions in both the
``Baseline'' and ``Action'' scenarios regarding control measures that
are external to the transportation system itself, such as vehicle
tailpipe or evaporative emission standards, limits on gasoline
volatility, vehicle inspection and maintenance programs, and oxygenated
or reformulated gasoline or diesel fuel.
    (6) The ambient temperatures used for the regional emissions
analysis shall be consistent with those used to establish the emissions
budget in the applicable implementation plan. All other factors, for
example the fraction of travel in a hot stabilized engine mode, must be
consistent with the applicable implementation plan, unless modified
after interagency consultation according to Sec. 93.105(c)(1)(i) to
incorporate additional or more geographically specific information or
represent a logically estimated trend in such factors beyond the period
considered in the applicable implementation plan.
    (7) Reasonable methods shall be used to estimate nonattainment or
maintenance area VMT on off-network roadways within the urban
transportation planning area, and on roadways outside the urban
transportation planning area.
    (b) Regional emissions analysis in serious, severe, and extreme
ozone nonattainment areas and serious CO nonattainment areas must meet
the requirements of paragraphs (b)(1) through (3) of this section if
their metropolitan planning area contains an urbanized area population
over 200,000.
    (1) By January 1, 1997, estimates of regional transportation-
related emissions used to support conformity determinations must be
made at a minimum using network-based travel models according to
procedures and methods that are available and in practice and supported
by current and available documentation. These procedures, methods, and
practices are available from DOT and will be updated periodically.
Agencies must discuss these modeling procedures and practices through
the interagency consultation process, as required by
Sec. 93.105(c)(1)(i). Network-based travel models must at a minimum
satisfy the following requirements:
    (i) Network-based travel models must be validated against observed
counts (peak and off-peak, if possible) for a base year that is not
more than 10 years prior to the date of the conformity determination.
Model forecasts must be analyzed for reasonableness and compared to
historical trends and other factors, and the results must be
documented;
    (ii) Land use, population, employment, and other network-based
travel model assumptions must be documented and based on the best
available information;
    (iii) Scenarios of land development and use must be consistent with
the future transportation system alternatives for which emissions are
being estimated. The distribution of employment and residences for
different transportation options must be reasonable;
    (iv) A capacity-sensitive assignment methodology must be used, and
emissions estimates must be based on a methodology which differentiates
between peak and off-peak link volumes and speeds and uses speeds based
on final assigned volumes;
    (v) Zone-to-zone travel impedances used to distribute trips between
origin and destination pairs must be in reasonable agreement with the
travel times that are estimated from final assigned traffic volumes.
Where use of transit currently is anticipated to be a significant
factor in satisfying transportation demand, these times should also be
used for modeling mode splits; and
    (vi) Network-based travel models must be reasonably sensitive to
changes in the time(s), cost(s), and other factors affecting travel
choices.
    (2) Reasonable methods in accordance with good practice must be
used to estimate traffic speeds and delays in a manner that is
sensitive to the estimated volume of travel on each roadway segment
represented in the network-based travel model.
    (3) Highway Performance Monitoring System (HPMS) estimates of
vehicle miles traveled (VMT) shall be considered the primary measure of
VMT within the portion of the nonattainment or maintenance area and for
the functional classes of roadways included in HPMS, for urban areas
which are sampled on a separate urban area basis. For areas with
network-based travel models, a factor (or factors) may be developed to
reconcile and calibrate the network-based travel model estimates of VMT
in the base year of its validation to the HPMS estimates for the same
period. These factors may then be applied to model estimates of future
VMT. In this factoring process, consideration will be given to
differences between HPMS and network-based travel models, such as
differences in the facility coverage of the HPMS and the modeled
network description. Locally developed count-

[[Page 43815]]

 based programs and other departures from these procedures are
permitted subject to the interagency consultation procedures of
Sec. 93.105(c)(1)(i).
    (c) In all areas not otherwise subject to paragraph (b) of this
section, regional emissions analyses must use those procedures
described in paragraph (b) of this section if the use of those
procedures has been the previous practice of the MPO. Otherwise, areas
not subject to paragraph (b) of this section may estimate regional
emissions using any appropriate methods that account for VMT growth by,
for example, extrapolating historical VMT or projecting future VMT by
considering growth in population and historical growth trends for VMT
per person. These methods must also consider future economic activity,
transit alternatives, and transportation system policies.
    (d) PM10 from construction-related fugitive dust. (1)
For areas in which the implementation plan does not identify
construction-related fugitive PM10 as a contributor to the
nonattainment problem, the fugitive PM10 emissions
associated with highway and transit project construction are not
required to be considered in the regional emissions analysis.
    (2) In PM10 nonattainment and maintenance areas with
implementation plans which identify construction-related fugitive
PM10 as a contributor to the nonattainment problem, the
regional PM10 emissions analysis shall consider
construction-related fugitive PM10 and shall account for the
level of construction activity, the fugitive PM10 control
measures in the applicable implementation plan, and the dust-producing
capacity of the proposed activities.
    (e) Reliance on previous regional emissions analysis. (1) The TIP
may be demonstrated to satisfy the requirements of Secs. 93.118
(``Motor vehicle emissions budget'') or 93.119 (``Emission reductions
in areas without motor vehicle emissions budgets'') without new
regional emissions analysis if the regional emissions analysis already
performed for the plan also applies to the TIP. This requires a
demonstration that:
    (i) The TIP contains all projects which must be started in the
TIP's timeframe in order to achieve the highway and transit system
envisioned by the transportation plan;
    (ii) All TIP projects which are regionally significant are included
in the transportation plan with design concept and scope adequate to
determine their contribution to the transportation plan's regional
emissions at the time of the transportation plan's conformity
determination; and
    (iii) The design concept and scope of each regionally significant
project in the TIP is not significantly different from that described
in the transportation plan.
    (2) A project which is not from a conforming transportation plan
and a conforming TIP may be demonstrated to satisfy the requirements of
Sec. 93.118 or Sec. 93.119 without additional regional emissions
analysis if allocating funds to the project will not delay the
implementation of projects in the transportation plan or TIP which are
necessary to achieve the highway and transit system envisioned by the
transportation plan, and if the project is either:
    (i) Not regionally significant; or
    (ii) Included in the conforming transportation plan (even if it is
not specifically included in the latest conforming TIP) with design
concept and scope adequate to determine its contribution to the
transportation plan's regional emissions at the time of the
transportation plan's conformity determination, and the design concept
and scope of the project is not significantly different from that
described in the transportation plan.

Sec. 93.123  Procedures for determining localized CO and
PM10 concentrations (hot-spot analysis).

    (a) CO hot-spot analysis. (1) The demonstrations required by
Sec. 93.116 (``Localized CO and PM10 violations'') must be
based on quantitative analysis using the applicable air quality models,
data bases, and other requirements specified in 40 CFR part 51,
Appendix W (Guideline on Air Quality Models). These procedures shall be
used in the following cases, unless different procedures developed
through the interagency consultation process required in Sec. 93.105
and approved by the EPA Regional Administrator are used:
    (i) For projects in or affecting locations, areas, or categories of
sites which are identified in the applicable implementation plan as
sites of violation or possible violation;
    (ii) For projects affecting intersections that are at Level-of-
Service D, E, or F, or those that will change to Level-of-Service D, E,
or F because of increased traffic volumes related to the project;
    (iii) For any project affecting one or more of the top three
intersections in the nonattainment or maintenance area with highest
traffic volumes, as identified in the applicable implementation plan;
and
    (iv) For any project affecting one or more of the top three
intersections in the nonattainment or maintenance area with the worst
level of service, as identified in the applicable implementation plan.
    (2) In cases other than those described in paragraph (a)(1) of this
section, the demonstrations required by Sec. 93.116 may be based on
either:
    (i) Quantitative methods that represent reasonable and common
professional practice; or
    (ii) A qualitative consideration of local factors, if this can
provide a clear demonstration that the requirements of Sec. 93.116 are
met.
    (b) PM10 hot-spot analysis. (1) The hot-spot
demonstration required by Sec. 93.116 must be based on quantitative
analysis methods for the following types of projects:
    (i) Projects which are located at sites at which violations have
been verified by monitoring;
    (ii) Projects which are located at sites which have vehicle and
roadway emission and dispersion characteristics that are essentially
identical to those of sites with verified violations (including sites
near one at which a violation has been monitored); and
    (iii) New or expanded bus and rail terminals and transfer points
which increase the number of diesel vehicles congregating at a single
location.
    (2) Where quantitative analysis methods are not required, the
demonstration required by Sec. 93.116 may be based on a qualitative
consideration of local factors.
    (3) The identification of the sites described in paragraph
(b)(1)(i) and (ii) of this section, and other cases where quantitative
methods are appropriate, shall be determined through the interagency
consultation process required in Sec. 93.105. DOT may choose to make a
categorical conformity determination on bus and rail terminals or
transfer points based on appropriate modeling of various terminal
sizes, configurations, and activity levels.
    (4) The requirements for quantitative analysis contained in this
paragraph (b) will not take effect until EPA releases modeling guidance
on this subject and announces in the Federal Register that these
requirements are in effect.
    (c) General requirements. (1) Estimated pollutant concentrations
must be based on the total emissions burden which may result from the
implementation of the project, summed together with future background
concentrations. The total concentration must be estimated and analyzed
at appropriate receptor locations in the

[[Page 43816]]

area substantially affected by the project.
    (2) Hot-spot analyses must include the entire project, and may be
performed only after the major design features which will significantly
impact concentrations have been identified. The future background
concentration should be estimated by multiplying current background by
the ratio of future to current traffic and the ratio of future to
current emission factors.
    (3) Hot-spot analysis assumptions must be consistent with those in
the regional emissions analysis for those inputs which are required for
both analyses.
    (4) PM10 or CO mitigation or control measures shall be
assumed in the hot-spot analysis only where there are written
commitments from the project sponsor and/or operator to implement such
measures, as required by Sec. 93.125(a).
    (5) CO and PM10 hot-spot analyses are not required to
consider construction-related activities which cause temporary
increases in emissions. Each site which is affected by construction-
related activities shall be considered separately, using established
``Guideline'' methods. Temporary increases are defined as those which
occur only during the construction phase and last five years or less at
any individual site.

Sec. 93.124  Using the motor vehicle emissions budget in the applicable
implementation plan (or implementation plan submission).

    (a) In interpreting an applicable implementation plan (or
implementation plan submission) with respect to its motor vehicle
emissions budget(s), the MPO and DOT may not infer additions to the
budget(s) that are not explicitly intended by the implementation plan
(or submission). Unless the implementation plan explicitly quantifies
the amount by which motor vehicle emissions could be higher while still
allowing a demonstration of compliance with the milestone, attainment,
or maintenance requirement and explicitly states an intent that some or
all of this additional amount should be available to the MPO and DOT in
the emissions budget for conformity purposes, the MPO may not interpret
the budget to be higher than the implementation plan's estimate of
future emissions. This applies in particular to applicable
implementation plans (or submissions) which demonstrate that after
implementation of control measures in the implementation plan:
    (1) Emissions from all sources will be less than the total
emissions that would be consistent with a required demonstration of an
emissions reduction milestone;
    (2) Emissions from all sources will result in achieving attainment
prior to the attainment deadline and/or ambient concentrations in the
attainment deadline year will be lower than needed to demonstrate
attainment; or
    (3) Emissions will be lower than needed to provide for continued
maintenance.
    (b) If an applicable implementation plan submitted before November
24, 1993, demonstrates that emissions from all sources will be less
than the total emissions that would be consistent with attainment and
quantifies that ``safety margin,'' the State may submit an
implementation plan revision which assigns some or all of this safety
margin to highway and transit mobile sources for the purposes of
conformity. Such an implementation plan revision, once it is endorsed
by the Governor and has been subject to a public hearing, may be used
for the purposes of transportation conformity before it is approved by
EPA.
    (c) A conformity demonstration shall not trade emissions among
budgets which the applicable implementation plan (or implementation
plan submission) allocates for different pollutants or precursors, or
among budgets allocated to motor vehicles and other sources, unless the
implementation plan establishes appropriate mechanisms for such trades.
    (d) If the applicable implementation plan (or implementation plan
submission) estimates future emissions by geographic subarea of the
nonattainment area, the MPO and DOT are not required to consider this
to establish subarea budgets, unless the applicable implementation plan
(or implementation plan submission) explicitly indicates an intent to
create such subarea budgets for the purposes of conformity.
    (e) If a nonattainment area includes more than one MPO, the
implementation plan may establish motor vehicle emissions budgets for
each MPO, or else the MPOs must collectively make a conformity
determination for the entire nonattainment area.

Sec. 93.125  Enforceability of design concept and scope and project-
level mitigation and control measures.

    (a) Prior to determining that a transportation project is in
conformity, the MPO, other recipient of funds designated under title 23
U.S.C. or the Federal Transit Laws, FHWA, or FTA must obtain from the
project sponsor and/or operator written commitments to implement in the
construction of the project and operation of the resulting facility or
service any project-level mitigation or control measures which are
identified as conditions for NEPA process completion with respect to
local PM10 or CO impacts. Before a conformity determination
is made, written commitments must also be obtained for project-level
mitigation or control measures which are conditions for making
conformity determinations for a transportation plan or TIP and are
included in the project design concept and scope which is used in the
regional emissions analysis required by Secs. 93.118 (``Motor vehicle
emissions budget'') and 93.119 (``Emission reductions in areas without
motor vehicle emissions budgets'') or used in the project-level hot-
spot analysis required by Sec. 93.116.
    (b) Project sponsors voluntarily committing to mitigation measures
to facilitate positive conformity determinations must comply with the
obligations of such commitments.
    (c) The implementation plan revision required in Sec. 51.390 of
this chapter shall provide that written commitments to mitigation
measures must be obtained prior to a positive conformity determination,
and that project sponsors must comply with such commitments.
    (d) If the MPO or project sponsor believes the mitigation or
control measure is no longer necessary for conformity, the project
sponsor or operator may be relieved of its obligation to implement the
mitigation or control measure if it can demonstrate that the applicable
hot-spot requirements of Sec. 93.116, emission budget requirements of
Sec. 93.118, and emission reduction requirements of Sec. 93.119 are
satisfied without the mitigation or control measure, and so notifies
the agencies involved in the interagency consultation process required
under Sec. 93.105. The MPO and DOT must find that the transportation
plan and TIP still satisfy the applicable requirements of Secs. 93.118
and/or 93.119 and that the project still satisfies the requirements of
Sec. 93.116, and therefore that the conformity determinations for the
transportation plan, TIP, and project are still valid. This finding is
subject to the applicable public consultation requirements in
Sec. 93.105(e) for conformity determinations for projects.

Sec. 93.126  Exempt projects.

    Notwithstanding the other requirements of this subpart, highway and
transit projects of the types listed in Table 2 of this section are
exempt from the requirement to determine

[[Page 43817]]

conformity. Such projects may proceed toward implementation even in the
absence of a conforming transportation plan and TIP. A particular
action of the type listed in Table 2 of this section is not exempt if
the MPO in consultation with other agencies (see
Sec. 93.105(c)(1)(iii)), the EPA, and the FHWA (in the case of a
highway project) or the FTA (in the case of a transit project) concur
that it has potentially adverse emissions impacts for any reason.
States and MPOs must ensure that exempt projects do not interfere with
TCM implementation. Table 2 follows:

                        Table 2.--Exempt Projects
------------------------------------------------------------------------

-------------------------------------------------------------------------
                                 Safety

Railroad/highway crossing.
Hazard elimination program.
Safer non-Federal-aid system roads.
Shoulder improvements.
Increasing sight distance.
Safety improvement program.
Traffic control devices and operating assistance other than
 signalization projects.
Railroad/highway crossing warning devices.
Guardrails, median barriers, crash cushions.
Pavement resurfacing and/or rehabilitation.
Pavement marking demonstration.
Emergency relief (23 U.S.C. 125).
Fencing.
Skid treatments.
Safety roadside rest areas.
Adding medians.
Truck climbing lanes outside the urbanized area.
Lighting improvements.
Widening narrow pavements or reconstructing bridges (no additional
 travel lanes).
Emergency truck pullovers.

                              Mass Transit

Operating assistance to transit agencies.
Purchase of support vehicles.
Rehabilitation of transit vehicles \1\.
Purchase of office, shop, and operating equipment for existing
 facilities.
Purchase of operating equipment for vehicles (e.g., radios, fareboxes,
 lifts, etc.).
Construction or renovation of power, signal, and communications systems.
Construction of small passenger shelters and information kiosks.
Reconstruction or renovation of transit buildings and structures (e.g.,
 rail or bus buildings, storage and maintenance facilities, stations,
 terminals, and ancillary structures).
Rehabilitation or reconstruction of track structures, track, and
 trackbed in existing rights-of-way.
Purchase of new buses and rail cars to replace existing vehicles or for
 minor expansions of the fleet \1\.
Construction of new bus or rail storage/maintenance facilities
 categorically excluded in 23 CFR part 771.

                               Air Quality
Continuation of ride-sharing and van-pooling promotion activities at
 current levels.
Bicycle and pedestrian facilities.

                                  Other

Specific activities which do not involve or lead directly to
 construction, such as:
    Planning and technical studies.
    Grants for training and research programs.
    Planning activities conducted pursuant to titles 23 and 49 U.S.C.
    Federal-aid systems revisions.
Engineering to assess social, economic, and environmental effects of the
 proposed action or alternatives to that action.
Noise attenuation.
Emergency or hardship advance land acquisitions (23 CFR 712.204(d)).
Acquisition of scenic easements.
Plantings, landscaping, etc.
Sign removal.
Directional and informational signs.
Transportation enhancement activities (except rehabilitation and
 operation of historic transportation buildings, structures, or
 facilities).
Repair of damage caused by natural disasters, civil unrest, or terrorist
 acts, except projects involving substantial functional, locational or
 capacity changes.
------------------------------------------------------------------------
Note: \1\In PM10 nonattainment or maintenance areas, such projects are
  exempt only if they are in compliance with control measures in the
  applicable implementation plan.

Sec. 93.127  Projects exempt from regional emissions analyses.

    Notwithstanding the other requirements of this subpart, highway and
transit projects of the types listed in Table 3 of this section are
exempt from regional emissions analysis requirements. The local effects
of these projects with respect to CO or PM10 concentrations
must be considered to determine if a hot-spot analysis is required
prior to making a project-level conformity determination. These
projects may then proceed to the project development process even in
the absence of a conforming transportation plan and TIP. A particular
action of the type listed in Table 3 of this section is not exempt from
regional emissions analysis if the MPO in consultation with other
agencies (see Sec. 93.105(c)(1)(iii)), the EPA, and the FHWA (in the

[[Page 43818]]

case of a highway project) or the FTA (in the case of a transit
project) concur that it has potential regional impacts for any reason.
Table 3 follows:

       Table 3.--Projects Exempt From Regional Emissions Analyses
------------------------------------------------------------------------

-------------------------------------------------------------------------
Intersection channelization projects.
Intersection signalization projects at individual intersections.
Interchange reconfiguration projects.
Changes in vertical and horizontal alignment.
Truck size and weight inspection stations.
Bus terminals and transfer points.
------------------------------------------------------------------------

Sec. 93.128  Traffic signal synchronization projects.

    Traffic signal synchronization projects may be approved, funded,
and implemented without satisfying the requirements of this subpart.
However, all subsequent regional emissions analyses required by
Secs. 93.118 and 93.119 for transportation plans, TIPs, or projects not
from a conforming plan and TIP must include such regionally significant
traffic signal synchronization projects.

[FR Doc. 97-20968 Filed 8-14-97; 8:45 am]
BILLING CODE 6560-50-P


 
 


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