[Federal Register Volume 62, Number 158 (Friday, August 15, 1997)]
[Rules and Regulations]
[Pages 43780-43818]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 97-20968]



[[Page 43779]]

_______________________________________________________________________

Part II





Environmental Protection Agency





_______________________________________________________________________



40 CFR Parts 51 and 93



Transportation Conformity Rule Amendments: Flexibility and 
Streamlining; Final Rule

  Federal Register / Vol. 62, No. 158 / Friday, August 15, 1997 / Rules 
and Regulations  

[[Page 43780]]



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.

-----------------------------------------------------------------------

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, [email protected]. (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/docs/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

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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 
applicable requirements of the conformity rule (for example, a 
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