PLAAPCD APPENDIX B-2
LAST REVISED 11/11/11




For the reasons set out in the preamble, title 40, chapter I,
part 51 of the Code of Federal Regulations is amended as follows.

PART 51--[AMENDED]

     1.   The authority citation for part 51 continues to read as
          follows:
          Authority:  42 U.S.C. 7401 - 7671p
     2.   Part 51 is amended by adding a new subpart T to read as
          follows: 


          Table of Contents
                      Transportation Conformity Rule

51.390        Purpose.. . . . . . . . . . . . . . . . . . . . . . . . .  1

51.392        Definitions.. . . . . . . . . . . . . . . . . . . . . . .  1

51.394        Applicability.. . . . . . . . . . . . . . . . . . . . . .  8

51.396        Implementation plan revision. . . . . . . . . . . . . . .  9

51.398        Priority. . . . . . . . . . . . . . . . . . . . . . . . .  9

51.400        Frequency of conformity determinations. . . . . . . . . .  9

51.402        Consultation. . . . . . . . . . . . . . . . . . . . . .   10

51.404        Content of transportation plans.. . . . . . . . . . . . . 12

51.406        Relationship of transportation plan and TIP
               conformity with the NEPA process. . . . . . . . . . . . . 13

51.408        Fiscal constraints for transportation plans and
               TIPs. . . . . . . . . . . . . . . . . . . . . . . . . . . 13

51.410        Criteria and procedures for determining conformity
               of transportation plans, programs, and projects: 
               General.. . . . . . . . . . . . . . . . . . . . . . . . . 14

51.412        Criteria and procedures:  Latest planning
               assumptions.. . . . . . . . . . . . . . . . . . . . . . . 17

51.414        Criteria and procedures:  Latest emissions model. . . . . 18

51.416        Criteria and procedures:  Consultation. . . . . . . . . . 18

51.418        Criteria and procedures:  Timely implementation of
               TCMs. . . . . . . . . . . . . . . . . . . . . . . . . . . 18

51.420        Criteria and procedures:  Currently conforming
               transportation plan and TIP.. . . . . . . . . . . . . . . 19

51.422        Criteria and procedures:  Projects from a plan and
               TIP.. . . . . . . . . . . . . . . . . . . . . . . . . . . 19

51.424        Criteria and procedures:  Localized CO and PM10
               violations (hot spots). . . . . . . . . . . . . . . . . . 20

51.426        Criteria and procedures:  Compliance with PM10
               control measures. . . . . . . . . . . . . . . . . . . . . 20

51.428        Criteria and procedures:  Motor vehicle emissions
               budget (transportation plan). . . . . . . . . . . . . . . 20

51.430        Criteria and procedures:  Motor vehicle emissions
               budget (TIP). . . . . . . . . . . . . . . . . . . . . . . 21

51.432        Criteria and procedures:   Motor vehicle emissions
               budget (project not from a plan and TIP). . . . . . . . . 22

51.434        Criteria and procedures:   Localized CO violations 
                              (hot spots) in the interim period.. . . . . . . . . . . . 2351.436        Criteria and procedures:  Interim period
               reductions in ozone and CO areas (transportation
               plan).. . . . . . . . . . . . . . . . . . . . . . . . . . 23

51.438        Criteria and procedures:  Interim period
               reductions in ozone and CO areas (TIP). . . . . . . . . . 24

51.440        Criteria and procedures:  Interim period
               reductions for ozone and CO areas (project not
               from a plan and TIP) . . .. . . . . . . . . . . . . . . . 26

51.442        Criteria and procedures:  Interim period
               reductions for PM10 and NO2 areas (transportation
               plan).. . . . . . . . . . . . . . . . . . . . . . . . . . 26

51.444        Criteria and procedures:  Interim period
               reductions for PM10 and NO2 areas (TIP).. . . . . . . . . 27

51.446        Criteria and procedures:  Interim period
               reductions for PM10 and NO2 areas (project not from
               a plan and TIP).. . . . . . . . . . . . . . . . . . . . . 28

51.448        Transition from the interim period to the control
               strategy period.. . . . . . . . . . . . . . . . . . . . . 28

51.450        Requirements for adoption or approval of projects
               by recipients of funds designated under title 23
               U.S.C. or the Federal Transit Act.  . . . . . . . . . . . 31

51.452        Procedures for determining regional
               transportation-related emissions. . . . . . . . . . . . . 32

51.454        Procedures for determining localized CO and PM10
               concentrations (hot-spot analysis). . . . . . . . . . . . 35

51.456        Using the motor vehicle emissions budget in the
               applicable implementation plan (or implementation
               plan submission). . . . . . . . . . . . . . . . . . . . . 36

51.458        Enforceability of design concept and scope and
               project-level mitigation and control measures.. . . . . . 36

51.460        Exempt projects.. . . . . . . . . . . . . . . . . . . . . 37

51.462        Projects exempt from regional emissions analyses. . . . . 39

51.464        Special provisions for nonattainment areas which
               are not required to demonstrate reasonable further
                              progress and attainment.. . . . . . . . . . . . . . . . . 40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 ACT

51.390   Purpose.

The purpose of this subpart is to implement 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 Act (49 U.S.C. 1601 et seq.).  This
subpart sets forth policy, criteria, and procedures for
demonstrating and assuring conformity of such activities to an
applicable implementation plan developed pursuant to 110 and
Part D of the CAA. 

51.392   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 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
110, or promulgated under 110(c), or promulgated or approved
pursuant to regulations promulgated under 301(d) and which
implements the relevant requirements of the CAA.

CAA means the Clean Air Act, as amended.

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.

Control strategy implementation plan revision is the applicable
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
182(b)(1), 182(c)(2)(A), 182(c)(2)(B), 187(a)(7), 189(a)(1)(B),
and 189(b)(1)(A); and 192(a) and 192(b), for nitrogen dioxide).

Control strategy period with respect to particulate matter less
than 10 microns in diameter (PM10), carbon monoxide (CO), nitrogen
dioxide (NO2), and/or ozone precursors (volatile organic
compounds and oxides of nitrogen), means that period of time
after EPA approves control strategy implementation plan revisions
containing strategies for controlling PM10, NO2, CO, and/or ozone,
as appropriate.  This period ends when a State submits and EPA
approves a request under 107(d) of the CAA for redesignation to
an attainment area.

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.

FTA means the Federal Transit Administration of DOT.

Forecast period with respect to a transportation plan is the
period covered by the transportation plan pursuant to 23 CFR part
450.

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
51.404 of this subpart.

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. 
Pollutant concentrations to be estimated should be based on the
total emissions burden which may result from the implementation
of a single, specific project, summed together with future
background concentrations (which can be estimated using the ratio
of future to current traffic multiplied by the ratio of future to
current emission factors) expected in the area.  The total
concentration must be estimated and analyzed at appropriate
receptor locations in the area substantially affected by the
project.  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.

Incomplete data area means any ozone nonattainment area which EPA
has classified, in 40 CFR part 81, as an incomplete data area.

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.

ISTEA means the Intermodal Surface Transportation Efficiency Act
of 1991.

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
175A of the CAA, as amended.

Maintenance period with respect to a pollutant or pollutant
precursor means that period of time beginning when a State
submits and EPA approves a request under 107(d) of the CAA for
redesignation to an attainment area, and lasting for 20 years,
unless the applicable implementation plan specifies that the
maintenance period shall last for more than 20 years.

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. 1607.  It is
the forum for cooperative transportation decision-making.

Milestone has the meaning given in 182(g)(1) and 189(c) of the
CAA.  A milestone consists of an 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 a revision to the applicable
implementation plan (or in an implementation plan revision which
was endorsed by the Governor or his or her designee, subject to a
public hearing, and submitted to EPA, but not yet approved by
EPA) for a certain date for the purpose of meeting reasonable
further progress milestones or attainment or maintenance
demonstrations, for any criteria pollutant or its precursors,
allocated by the applicable implementation plan to highway and
transit vehicles.  The applicable implementation plan for an
ozone nonattainment area may also designate a motor vehicle
emissions budget for oxides of nitrogen (NOx) for a reasonable
further progress milestone year if the applicable implementation
plan demonstrates that this NOx budget will be achieved with
measures in the implementation plan (as an implementation plan
must do for VOC milestone requirements).  The  applicable
implementation plan for an ozone nonattainment area includes a
NOx budget if NOx reductions are being substituted for reductions
in volatile organic compounds in milestone years required for
reasonable further progress.

National ambient air quality standards (NAAQS) are those
standards established pursuant to 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 107 of
the CAA for any pollutant for which a national ambient air
quality standard exists.

Not classified area means any carbon monoxide nonattainment area
which EPA has not classified as either moderate or serious.

Phase II of the interim period with respect to a pollutant or
pollutant precursor means that period of time after the effective
date of this rule, lasting until the earlier of the following:
     (1)  submission to EPA of the relevant control strategy
          implementation plan revisions which have been endorsed
          by the Governor (or his or her designee) and have been
          subject to a public hearing, or
     (2)  the date that the Clean Air Act requires relevant
          control strategy implementation plans to be submitted
          to EPA, provided EPA has notified the State, MPO, and
          DOT of the State's failure to submit any such plans. 
          The precise end of Phase II of the interim period is
          defined in 51.448 of this subpart.

Project means a highway project or transit project.

Recipient of funds designated under title 23 U.S.C. or the
Federal Transit Act means any agency at any level of State,
county, city, or regional government that routinely receives
title 23 U.S.C. or Federal Transit Act 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.

Rural transport ozone nonattainment area means an ozone
nonattainment area that does not include, and is not adjacent to,
any part of a Metropolitan Statistical Area or, where one exists,
a Consolidated Metropolitan Statistical Area (as defined by the
United States Bureau of the Census) and is classified under Clean
Air Act 182(h) as a rural transport area.

Standard means a national ambient air quality standard.

Submarginal area means any ozone nonattainment area which EPA has
classified as submarginal in 40 CFR part 81.

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.

Transitional area means any ozone nonattainment area which EPA
has classified as transitional in 40 CFR part 81.

Transitional period with respect to a pollutant or pollutant
precursor means that period of time which begins after submission
to EPA of the relevant control strategy implementation plan which
has been endorsed by the Governor (or his or her designee) and
has been subject to a public hearing.  The transitional period
lasts until EPA takes final approval or disapproval action on the
control strategy implementation plan submission or finds it to be
incomplete.  The precise beginning and end of the transitional
period is defined in 51.448 of this subpart.

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
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 above, 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.

51.394   Applicability.

(a)  Action applicability.
     (1)  Except as provided for in paragraph (c) of this section
          or 51.460, conformity determinations are required for:
          (i)  The adoption, acceptance, approval or support of
               transportation plans 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 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
          rule for individual projects which are not FHWA/FTA
          projects.  However, 51.450 applies to such projects if
          they are regionally significant.
(b)  Geographic Applicability.
     (1)  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.
     (2)  The provisions of this subpart apply with respect to
          emissions of the following criteria pollutants:  ozone,
          carbon monoxide, nitrogen dioxide, and particles with
          an aerodynamic diameter less than or equal to a nominal
          10 micrometers (PM10).
     (3)  The provisions of this subpart apply with respect to
          emissions of the following precursor pollutants:
          (i)  Volatile organic compounds and nitrogen oxides in
               ozone areas (unless the Administrator determines
               under 182(f) of the CAA that additional
               reductions of NOx would not contribute to
               attainment);
          (ii) Nitrogen oxides in nitrogen dioxide areas; and
          (iii)     Volatile organic compounds, nitrogen oxides,
                    and PM10 in PM10 areas if:
               (A)  During the interim period, 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
               (B)  During the transitional, control strategy,
                    and maintenance periods, 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.
(c)  Limitations.
     (1)  Projects subject to this regulation for which the NEPA
          process and a conformity determination have been
          completed by FHWA or FTA may proceed toward
          implementation without further conformity
          determinations if one of the following major steps has
          occurred within the past three years:  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.   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 no major steps to advance the project
          have occurred within the past three years.

51.396   Implementation plan revision.

(a)  States with areas subject to this rule 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 these regulations.  This revision is to be submitted by
     November 24, 1994 (or within 12 months of an area's
     redesignation from attainment to nonattainment, if the State
     has not previously submitted such a revision).  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 these
     regulations only if the State's conformity provisions apply
     equally to non-federal as well as Federal entities.
(b)  The Federal conformity rules under this subpart and 40 CFR
     part 93, 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 the required
     conformity implementation plan revision is approved by EPA. 
     Following EPA approval of the State conformity provisions
     (or a portion thereof) in a revision to the applicable
     implementation plan, the approved (or approved portion of
     the) State criteria and procedures would govern conformity
     determinations and the Federal conformity regulations
     contained in 40 CFR part 93 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 requirements relating to
     conformity remain enforceable until the State revises its
     applicable implementation plan to specifically remove them
     and that revision is approved by EPA.
(c)  To be approvable by EPA, the implementation plan revision
     submitted to EPA and DOT under this section shall address
     all requirements of this subpart in a manner which gives
     them full legal effect.  In particular, the revision shall
     incorporate the provisions of the following sections of this
     subpart in verbatim form, except insofar as needed to give
     effect to a stated intent in the revision to establish
     criteria and procedures more stringent than the requirements
     stated in these sections:  51.392, 51.394, 51.398, 51.400,
     51.404, 51.410, 51.412, 51.414, 51.416, 51.418, 51.420,
     51.422, 51.424, 51.426, 51.428, 51.430, 51.432, 51.434,
     51.436, 51.438, 51.440, 51.442, 51.444, 51.446, 51.448,
     51.450, 51.460, and 51.462.

51.398   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.

51.400   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)  Transportation plans.
     (1)  Each new transportation plan must be found 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 MPO or accepted by DOT, unless the revision
          merely adds or deletes exempt projects listed in
          51.460.   The conformity determination must be based
          on the transportation plan and the revision taken as a
          whole.
     (3)  Conformity of existing transportation plans must be
          redetermined within 18 months of the following, or the
          existing conformity determination will lapse:
          (i)  November 24, 1994;
          (ii) EPA approval of an implementation plan revision
               which:
               (A)  Establishes or revises a transportation-
                    related emissions budget (as required by CAA
                    175A(a), 182(b)(1), 182(c)(2)(A),
                    182(c)(2)(B), 187(a)(7), 189(a)(1)(B), and
                    189(b)(1)(A); and 192(a) and 192(b), for
                    nitrogen dioxide); or
               (B)  Adds, deletes, or changes TCMs; and
          (iii)     EPA promulgation of an implementation plan
                    which  establishes or revises a
                    transportation-related emissions budget or
                    adds, deletes, or changes TCMs.
     (4)  In any case, conformity determinations must be made no
          less frequently than every three years, or the existing
          conformity determination will lapse.
(c)  Transportation improvement programs.
     (1)  A new TIP must be found 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 51.460.
     (3)  After an MPO adopts a new or revised transportation
          plan, conformity must be redetermined by the MPO and
          DOT within six months from the date of adoption of the
          plan, unless the new or revised plan merely adds or
          deletes exempt projects listed in 51.460.  Otherwise,
          the existing conformity determination for the TIP will
          lapse.
     (4)  In any case, conformity determinations must be made no
          less frequently than every three years or the existing
          conformity determination 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 none of the
     following major steps has occurred within the past three
     years:  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.

51.402   Consultation.

(a)  General.
     The implementation plan revision required under 51.396
     shall include procedures for interagency consultation
     (Federal, State, and local) and resolution of conflicts.
     (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 the implementation plan revision is approved by
          EPA, MPOs and State departments of transportation
          before making conformity determinations 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.  
(b)  Interagency consultation procedures:  General factors.
     (1)  States shall provide in the implementation plan well-
          defined consultation procedures 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 general factors listed below 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 51.460 and 51.462) 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
               51.418(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 51.454(d), 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; and
          (vi) Notification of transportation plan or TIP
               revisions or amendments which merely add or delete
               exempt projects listed in 51.460.
     (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 51.400; 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 Act, 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 Act 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 51.452.
     (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 (including Federal agencies) for providing
          final documents (including applicable implementation
          plans and implementation plan revisions) and supporting
          information to each agency after approval or adoption.
(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 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 51.396 shall
     define the procedures for starting of 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 prior to taking
     formal action on a conformity determination for all
     transportation plans and TIPs, consistent with the
     requirements of 23 CFR part 450.  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.

51.404   Content of transportation plans.

(a)  Transportation plans adopted after January 1, 1995 in
     serious, severe, or extreme ozone nonattainment areas and in
     serious carbon monoxide nonattainment areas.
     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.
          (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 51.402;
          (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 sufficiently to allow modeling
               of their transit ridership.  The description of
               additions and modifications to the transportation
               network shall also be sufficiently specific 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 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,
     transportation plans must describe the transportation system
     envisioned for the future specifically enough to allow
     determination of conformity according to the criteria and
     procedures of 51.410 - 51.446.
(d)  Savings.
     The requirements of this section supplement other
     requirements of applicable law or regulation governing the
     format or content of transportation plans.

51.406   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 51.410 - 51.446 for
projects not from a TIP before NEPA process completion.

51.408   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.

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

(a)  In order to be found to conform, each transportation plan,
     program, and FHWA/FTA project must satisfy the applicable
     criteria and procedures in 51.412 - 51.446 as listed in
     Table 1 in paragraph (b) of this section, and must comply
     with all applicable conformity requirements of
     implementation plans and of court orders for the area which
     pertain specifically to conformity determination
     requirements. The criteria for making conformity
     determinations differ based on the action under review
     (transportation plans, TIPs, and FHWA/FTA projects), the
     time period in which the conformity determination is made,
     and the relevant pollutant.
(b)  The following table indicates the criteria and procedures in
     51.412 - 51.446 which apply for each action in each time
     period.

                  [ All tables begin on the next page ]
                     Table 1.   Conformity Criteria



                                           ALL PERIODS
   -------------------------------------------------------
   |           Action          |         Criteria        |
   -------------------------------------------------------
   | Transportation Plan       | 51.412, 51.414, 51.416,
   |
   |                           | 51.418(b)               |
   -------------------------------------------------------
   | TIP                       | 51.412, 51.414, 51.416,
   |
   |                           | 51.418(c)               |
   -------------------------------------------------------
   | Project (from a           | 51.412, 51.414, 51.416,
   |
   | conforming plan and TIP)  | 51.420, 51.422, 51.424, |
   |                           | 51.426                  |
   -------------------------------------------------------
   | Project (not from a       | 51.412, 51.414, 51.416,
   |
   | conforming plan and TIP)  | 51.418(d), 51.420,      |
   |                           | 51.424, 51.426          |
   -------------------------------------------------------






                  PHASE II OF THE INTERIM PERIOD
    -------------------------------------------------------
    |           Action          |         Criteria        |
    -------------------------------------------------------
    | Transportation Plan       | 51.436, 51.442        |
    -------------------------------------------------------
    | TIP                       | 51.438, 51.444        |
    -------------------------------------------------------
    | Project (from a           | 51.434                |
    | conforming plan and TIP)  |                         |
    -------------------------------------------------------
     Project (not from a       | 51.434, 51.440, 51.446|
    | conforming plan and TIP)  |                         |
    -------------------------------------------------------
 

                Table 1.   Conformity Criteria (continued)



                      TRANSITIONAL PERIOD
     -------------------------------------------------------
     |           Action          |         Criteria        |
     -------------------------------------------------------
     | Transportation Plan       | 51.428, 51.436, 51.442|
     -------------------------------------------------------
     | TIP                       | 51.430, 51.438, 51.444|
     -------------------------------------------------------
     | Project (from a           | 51.434                |
     | conforming plan and TIP)  |                         |
     -------------------------------------------------------
     | Project (not from a       | 51.432, 51.434, 51.440,
     |
     | conforming plan and TIP)  | 51.446                  |
     -------------------------------------------------------





                   CONTROL STRATEGY AND MAINTENANCE PERIODS
      -------------------------------------------------------
      |           Action          |         Criteria        |
      -------------------------------------------------------
      | Transportation Plan       | 51.428                |
      -------------------------------------------------------
      | TIP                       | 51.430                |
      -------------------------------------------------------
      | Project (from a           | no additional criteria  |
      | conforming plan and TIP)  |                         |
      -------------------------------------------------------
      | Project (not from a       | 51.432                |
      | conforming plan and TIP)  |                         |
      -------------------------------------------------------
     

               51.412    The conformity determination must be based on the latest
          planning assumptions. 
51.414    The conformity determination must be based on the latest
          emission estimation model available.
51.416    The MPO must make the conformity determination according
          to the consultation procedures of this rule and the
          implementation plan revision required by 51.396.
51.418    The transportation plan, TIP, or 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.
51.420    There must be a currently conforming transportation plan
          and currently conforming TIP at the time of project
          approval.
51.422    The project must come from a conforming transportation
          plan and program.
51.424    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.
51.426    The FHWA/FTA project must comply with PM10 control
          measures in the applicable implementation plan.
51.428    The transportation plan must be consistent with the motor
          vehicle emissions budget(s) in the applicable
          implementation plan or implementation plan submission.
51.430    The TIP must be consistent with the motor vehicle
          emissions budget(s) in the applicable implementation plan
          or implementation plan submission.
51.432    The project which is not from a conforming transportation
          plan and conforming TIP must be consistent with the motor
          vehicle emissions budget(s) in the applicable
          implementation plan or implementation plan submission.
51.434    The 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).
51.436    The transportation plan must contribute to emissions
          reductions in ozone and CO nonattainment areas.
51.438    The TIP must contribute to emissions reductions in ozone
          and CO nonattainment areas.
51.440    The project which is not from a conforming transportation
          plan and TIP must contribute to emissions reductions in
          ozone and CO nonattainment areas.
51.442    The transportation plan must contribute to emission
          reductions or must not increase emissions in PM10 and NO2
          nonattainment areas.
51.444    The TIP must contribute to emission reductions or must
          not increase emissions in PM10 and NO2 nonattainment
          areas.
51.446    The project which is not from a conforming transportation
          plan and TIP must contribute to emission reductions or
          must not increase emissions in PM10 and NO2 nonattainment
          areas.

51.412   Criteria and procedures:  Latest planning assumptions.

(a)  The conformity determination, with respect to all other
     applicable criteria in 51.414 - 51.446, must be based upon
     the most recent planning assumptions in force at the time of
     the conformity determination.  This criterion applies during
     all periods.  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 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 51.402.

51.414   Criteria and procedures:  Latest emissions model.

(a)  The conformity determination must be based on the latest
     emission estimation model available.  This criterion applies
     during all periods.  It 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)  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 for transportation plans
     and TIPs.  The previous model may also be used for projects if
     the analysis was begun during the grace period or before the
     Federal Register notice of availability, provided no more than
     three years have passed since the draft environmental document
     was issued.

51.416   Criteria and procedures:  Consultation.

(a)  The MPO must make the conformity determination according to
     the consultation procedures in this rule and in the
     implementation plan revision required by 51.396, and
     according to the public involvement procedures established by
     the MPO in compliance with 23 CFR part 450.  This criterion
     applies during all periods.  Until the implementation plan
     revision required by 51.396 is approved by EPA, the
     conformity determination must be made according to the
     procedures in 51.402(a)(2) and 51.402(e).  Once the
     implementation plan revision has been approved by EPA, this
     criterion is satisfied if the conformity determination is made
     consistent with the implementation plan's consultation
     requirements.

51.418   Criteria and procedures:  Timely implementation of TCMs.

(a)  The transportation plan, TIP, or 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.  This criterion applies during all periods.
(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 Act,
          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 Act 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 under
          ISTEA's 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.

51.420   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.  This
criterion applies during all periods.  It is satisfied if the
current transportation plan and TIP have been found to conform to
the applicable implementation plan by the MPO and DOT according to
the procedures of this subpart.  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 of 51.400.

51.422   Criteria and procedures:  Projects from a plan and TIP.

(a)  The project must come from a conforming plan and program. 
     This criterion applies during all periods.  If this criterion
     is not satisfied, the project must satisfy all criteria in
     Table 1 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.
(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 51.404, 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 have
          not changed significantly from those which were described
          in the TIP, or in a manner which would significantly
          impact use of the facility; 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 51.458(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.

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

(a)  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 applies
     during all periods.  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.
(b)  The demonstration must be performed according to the
     requirements of 51.402(c)(1)(i) and 51.454.
(c)  For projects which are not of the type identified by
     51.454(a) or 51.454(d), this criterion may be satisfied if
     consideration of local factors clearly demonstrates that no
     local violations presently exist and no new local violations
     will be created as a result of the project.  Otherwise, in CO
     nonattainment and maintenance areas, a  quantitative
     demonstration must be performed according to the requirements
     of 51.454(b).

51.426   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 applies during all
periods.  It is satisfied if control measures (for the purpose of
limiting PM10 emissions from the construction activities and/or
normal use and operation associated with the project) contained in
the applicable implementation plan are included in the final plans,
specifications, and estimates for the project.

51.428   Criteria and procedures:  Motor vehicle emissions budget
          (transportation plan).

(a)  The transportation plan must be consistent with the motor
     vehicle emissions budget(s) in the applicable implementation
     plan (or implementation plan submission).  This criterion
     applies during the transitional period and the control
     strategy and maintenance periods, except as provided in
     51.464.  This criterion may be satisfied if the requirements
     in paragraphs (b) and (c) of this section are met:
(b)  A regional emissions analysis shall be performed as follows:
     (1)  The regional analysis shall estimate emissions of any of
          the following pollutants and pollutant precursors for
          which the area is in nonattainment or maintenance and for
          which the applicable implementation plan (or
          implementation plan submission) establishes an emissions
          budget:
          (i)  VOC as an ozone precursor;
          (ii) NOx as an ozone precursor, unless the Administrator
               determines that additional reductions of NOx would
               not contribute to attainment;
          (iii)     CO;
          (iv) PM10 (and its precursors VOC and/or NOx if the
               applicable implementation plan or implementation
               plan submission identifies transportation-related
               precursor emissions within the nonattainment area
               as a significant contributor to the PM10
               nonattainment problem or establishes a budget for
               such emissions); or
          (v)  NOx (in NO2 nonattainment or maintenance areas);
     (2)  The regional emissions analysis shall estimate 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;
     (3)  The emissions analysis methodology shall meet the
          requirements of 51.452;
     (4)  For areas with a transportation plan that meets the
          content requirements of 51.404(a), the emissions
          analysis shall be performed for each horizon year. 
          Emissions in milestone years which are between the
          horizon years may be determined by interpolation; and
     (5)  For areas with a transportation plan that does not meet
          the content requirements of 51.404(a), the emissions
          analysis shall be performed for any years in the time
          span of the transportation plan provided they are not
          more than ten years apart and provided the analysis is
          performed for the last year of the plan's forecast
          period.  If the attainment year is in the time span of
          the transportation plan, the emissions analysis must also
          be performed for the attainment year.  Emissions in
          milestone years which are between these analysis years
          may be determined by interpolation.
(c)  The regional emissions analysis shall demonstrate that for
     each of the applicable pollutants or pollutant precursors in
     paragraph (b)(1) of this section the emissions are less than
     or equal to the motor vehicle emissions budget as established
     in the applicable implementation plan or implementation plan
     submission as follows:
     (1)  If the applicable implementation plan or implementation
          plan submission establishes emissions budgets for
          milestone years, emissions in each milestone year are
          less than or equal to the motor vehicle emissions budget
          established for that year;
     (2)  For nonattainment areas, emissions in the attainment year
          are less than or equal to the motor vehicle emissions
          budget established in the applicable implementation plan
          or implementation plan submission for that year;
     (3)  For nonattainment areas, emissions in each analysis or
          horizon year after the attainment year are less than or
          equal to the motor vehicle emissions budget established
          by the applicable implementation plan or implementation
          plan submission for the attainment year.  If emissions
          budgets are established for years after the attainment
          year, emissions in each analysis year or horizon year
          must be less than or equal to the motor vehicle emissions
          budget for that year, if any, or the motor vehicle
          emissions budget for the most recent budget year prior to
          the analysis year or horizon year; and
     (4)  For maintenance areas, emissions in each analysis or
          horizon year are less than or equal to the motor vehicle
          emissions budget established by the maintenance plan for
          that year, if any, or the emissions budget for the most
          recent budget year prior to the analysis or horizon year.

51.430   Criteria and procedures:  Motor vehicle emissions budget
          (TIP).

(a)  The TIP must be consistent with the motor vehicle emissions
     budget(s) in the applicable implementation plan (or
     implementation plan submission).  This criterion applies
     during the transitional period and the control strategy and
     maintenance periods, except as provided in 51.464.  This
     criterion may be satisfied if the requirements in paragraphs
     (b) and (c) of this section are met.
(b)  For areas with a conforming transportation plan that fully
     meets the content requirements of 51.404(a), this criterion
     may be satisfied without additional regional analysis if:
     (1)  Each program year of the TIP is consistent with the
          Federal funding which may be reasonably expected for that
          year, and required State/local matching funds and funds
          for State/local funding-only projects are consistent with
          the revenue sources expected over the same period; and
     (2)  The TIP is consistent with the conforming transportation
          plan such that the regional emissions analysis already
          performed for the plan applies to the TIP also.  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 in each of its horizon years;
          (ii) All TIP projects which are regionally significant
               are part of the specific highway or transit system
               envisioned in the transportation plan's horizon
               years; 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.
     (3)  If the requirements in paragraphs (b)(1) and (b)(2) of
          this section are not met, then:
          (i)  The TIP may be modified to meet those requirements;
               or
          (ii) The transportation plan must be revised so that the
               requirements in paragraphs (b)(1) and (b)(2) of
               this section are met.  Once the revised plan has
               been found to conform, this criterion is met for
               the TIP with no additional analysis except a
               demonstration that the TIP meets the requirements
               of paragraphs (b)(1) and (b)(2) of this section.
(c)  For areas with a transportation plan that does not meet the
     content requirements of 51.404(a), a regional emissions
     analysis must meet all of the following requirements:
     (1)  The regional emissions analysis shall estimate emissions
          from the entire transportation system, including all
          projects contained in the proposed TIP, 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;
     (2)  The analysis methodology shall meet the requirements of
          51.452(c); and
     (3)  The regional analysis shall satisfy the requirements of
          51.428(b)(1), 51.428(b)(5), and 51.428(c).

51.432   Criteria and procedures:   Motor vehicle emissions budget
          (project not from a plan and TIP).

(a)  The project which is not from a conforming transportation plan
     and a conforming TIP must be consistent with the motor vehicle
     emissions budget(s) in the applicable implementation plan (or
     implementation plan submission).  This criterion applies
     during the transitional period and the control strategy and
     maintenance periods, except as provided in 51.464.  It is
     satisfied if emissions from the  implementation of the
     project, when considered with the emissions from the projects
     in the conforming transportation plan and TIP and all other
     regionally significant projects expected in the area, do not
     exceed the motor vehicle emissions budget(s) in the applicable
     implementation plan (or implementation plan submission).
(b)  For areas with a conforming transportation plan that meets the
     content requirements of 51.404(a):
     (1)  This criterion may be satisfied without additional
          regional analysis if the project is included in the
          conforming transportation plan, even if it is not
          specifically included in the latest conforming TIP.  This
          requires a demonstration that:
          (i)  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 in each of its horizon years;
          (ii) The project is not regionally significant or is
               part of the specific highway or transit system
               envisioned in the transportation plan's horizon
               years; and
          (iii)     The design concept and scope of the project is
                    not
               significantly different from that described in the
               transportation plan.
     (2)  If the requirements in paragraph (b)(1) of this section
          are not met, a regional emissions analysis must be
          performed as follows:
          (i)  The analysis methodology shall meet the
               requirements of 51.452;
          (ii) The analysis shall estimate emissions from the
               transportation system, including the proposed
               project and all other regionally significant
               projects expected in the nonattainment or
               maintenance area in the timeframe of the
               transportation plan.  The analysis must include
               emissions from all previously approved projects
               which were not from a transportation plan and TIP;
               and
          (iii)     The emissions analysis shall meet the
                    requirements of
               51.428(b)(1), 51.428(b)(4), and 51.428(c).
(c)  For areas with a transportation plan that does not meet the
     content requirements of 51.404(a), a regional emissions
     analysis must be performed for the project together with the
     conforming TIP and all other regionally significant projects
     expected in the nonattainment or maintenance area.  This
     criterion may be satisfied if:
     (1)  The analysis methodology meets the requirements of
          51.452(c);
     (2)  The analysis estimates emissions from the transportation
          system, including the proposed project, and all other
          regionally significant projects expected in the
          nonattainment or maintenance area in the timeframe of the
          transportation plan; and
     (3)  The regional analysis satisfies the requirements of
          51.428(b)(1), 51.428(b)(5), and 51.428(c).

51.434   Criteria and procedures:   Localized CO violations  (hot
          spots) in the interim period.

(a)  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 applies during the interim and
     transitional periods only.  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.
(b)  The demonstration must be performed according to the
     requirements of 51.402(c)(1)(i) and 51.454.
(c)  For projects which are not of the type identified by
     51.454(a), this criterion may be satisfied if consideration
     of local factors clearly demonstrates that existing CO
     violations will be eliminated or reduced in severity and
     number.  Otherwise, a quantitative demonstration must be
     performed according to the requirements of 51.454(b).

51.436   Criteria and procedures:  Interim period reductions in
          ozone and CO areas (transportation plan).

(a)  A transportation plan must contribute to emissions reductions
     in ozone and CO nonattainment areas.  This criterion applies
     during the interim and transitional periods only, except as
     otherwise provided in 51.464.  It applies to the net effect
     on emissions of all projects contained in a new or revised
     transportation plan.  This criterion may be satisfied if a
     regional emissions analysis is performed as described in
     paragraphs (b) through (f) of this section.
(b)  Determine the analysis years for which emissions are to be
     estimated.  Analysis years shall be no more than ten years
     apart.  The first analysis year shall be no later than the
     first milestone year (1995 in CO nonattainment areas and 1996
     in ozone nonattainment areas).  The second analysis year shall
     be either the attainment year for the area, or if the
     attainment year is the same as the first analysis year or
     earlier, the second analysis year shall be at least five years
     beyond the first analysis year.  The last year of the
     transportation plan's forecast period shall also be an
     analysis year.
(c)  Define the 'Baseline' scenario for each of the analysis years
     to be the future transportation system that would result from
     current programs, composed of the following (except that
     projects listed in 51.460 and 51.462 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 three years of the previously
          conforming  transportation plan and/or TIP; or have
          completed the NEPA process. (For the first conformity
          determination on the transportation plan after November
          24, 1993, a project may not be included in the "Baseline"
          scenario if one of the following major steps has not
          occurred within the past three years:  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.  Such a project
          must be included in the "Action" scenario, as described
          in paragraph (d) of this section.)
(d)  Define the 'Action' scenario for each of the analysis years as
     the transportation system that will result in that year from
     the implementation of the proposed transportation plan, TIPs
     adopted under it, and other expected regionally significant
     projects in the nonattainment area.  It will include the
     following (except that projects listed in 51.460 and 51.462
     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 on the transportation plan;
     (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 Federal funding or
          approval, which were adopted and/or funded prior to the
          date of the last conformity determination on the
          transportation plan, 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.
(e)  Estimate the emissions predicted to result in each analysis
     year from travel on the transportation systems defined by the
     'Baseline' and 'Action' scenarios and determine the difference
     in regional VOC and NOx emissions (unless the Administrator
     determines that additional  reductions of NOx would not
     contribute to attainment) between the two scenarios for ozone
     nonattainment areas and the difference in CO emissions between
     the two scenarios for CO nonattainment areas.  The analysis
     must be performed for each of the analysis years according to
     the requirements of 51.452.  Emissions in milestone years
     which are between the analysis years may be determined by
     interpolation.
(f)  This criterion is met if the regional VOC and NOx emissions
     (for ozone nonattainment areas) and CO emissions (for CO
     nonattainment areas) predicted in the 'Action' scenario are
     less than the emissions predicted from the 'Baseline' scenario
     in each analysis year, and if this can reasonably be expected
     to be true in the periods between the first milestone year and
     the analysis years.  The regional analysis must show that the
     'Action' scenario contributes to a reduction in emissions from
     the 1990 emissions by any nonzero amount.

51.438   Criteria and procedures:  Interim period reductions in
          ozone and CO areas (TIP).

(a)  A TIP must contribute to emissions reductions in ozone and CO
     nonattainment areas.  This criterion applies during the
     interim and transitional periods only, except as otherwise
     provided in 51.464.  It applies to the net effect on
     emissions of all projects contained in a new or revised TIP. 
     This criterion may be satisfied if a regional emissions
     analysis is performed as described in paragraphs (b) through
     (f) of this section.
(b)  Determine the analysis years for which emissions are to be
     estimated.  The first analysis year shall be no later than the
     first milestone year (1995 in CO nonattainment areas and 1996
     in ozone nonattainment areas).  The analysis years shall be no
     more than ten years apart.  The second analysis year shall be
     either the attainment year for the area, or if the attainment
     year is the same as the first analysis year or earlier, the
     second analysis year shall be at least five years beyond the
     first analysis year.  The last year of the transportation
     plan's forecast period shall also be an analysis year.
(c)  Define the 'Baseline' scenario as the future transportation
     system that would result from current programs, composed of
     the following (except that projects listed in 51.460 and
     51.462 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 three years of the previously
          conforming TIP; or have completed the NEPA process. (For
          the first conformity determination on the TIP after
          November 24, 1993, a project may not be  included in the
          "Baseline" scenario if one of the following major steps
          has not occurred within the past three years:  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.  Such a project
          must be included in the "Action" scenario, as described
          in paragraph (d) of this section.)
(d)  Define the 'Action' scenario as the future transportation
     system that will result from the implementation of the
     proposed TIP and other expected regionally significant
     projects in the nonattainment area in the timeframe of the
     transportation plan.  It will include the following (except
     that projects listed in 51.460 and 51.462 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)
          included in the proposed TIP, 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 contained 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 on the TIP;
     (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 Federal funding or
          approval, which were adopted and/or funded prior to the
          date of the last conformity determination on the TIP, 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.
(e)  Estimate the emissions predicted to result in each analysis
     year from travel on the transportation systems defined by the
     'Baseline' and 'Action' scenarios, and determine the
     difference in regional VOC and NOx emissions (unless the
     Administrator determines that additional reductions of NOx
     would not contribute to attainment) between the two scenarios
     for ozone nonattainment areas and the difference in CO
     emissions between the two scenarios for CO nonattainment
     areas.  The analysis must be performed for each of the
     analysis years according to the requirements of 51.452. 
     Emissions  in milestone years which are between analysis years
     may be determined by interpolation.
(f)  This criterion is met if the regional VOC and NOx emissions in
     ozone nonattainment areas and CO emissions in CO nonattainment
     areas predicted in the 'Action' scenario are less than the
     emissions predicted from the 'Baseline' scenario in each
     analysis year, and if this can reasonably be expected to be
     true in the period between the analysis years.  The regional
     analysis must show that the 'Action' scenario contributes to
     a reduction in emissions from the 1990 emissions by any
     nonzero amount.

51.440   Criteria and procedures:  Interim period reductions for
          ozone and CO areas (project not from a plan and TIP).

A Transportation  TIP must contribute to emissions reductions in
ozone and CO nonattainment areas.  This criterion applies during
the interim and transitional periods only, except as otherwise
provided in 51.464.  This criterion is satisfied if a regional
emissions analysis is performed which meets the requirements of
51.436 and which includes the transportation plan and project in
the 'Action' scenario.  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.

51.442   Criteria and procedures:  Interim period reductions for
          PM10 and NO2 areas (transportation plan).

(a)  A transportation plan must contribute to emission reductions
     or must not increase emissions in PM10 and NO2 nonattainment
     areas.  This criterion applies only during the interim and
     transitional periods.  It applies to the net effect on
     emissions of all projects contained in a new or revised
     transportation plan.  This criterion may be satisfied if the
     requirements of either paragraph (b) or (c) of this section
     are met.
(b)  Demonstrate that implementation of the plan and all other
     regionally significant projects expected in the nonattainment
     area will contribute to reductions in emissions of PM10 in a
     PM10 nonattainment area (and of each transportation-related
     precursor of PM10 in PM10 nonattainment 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 nonattainment area are a significant contributor to the
     PM10 nonattainment problem and has so notified the MPO and DOT)
     and of NOx in an NO2 nonattainment area, by performing a
     regional emissions analysis as follows:
     (1)  Determine the analysis years for which emissions are to
          be estimated.  Analysis years shall be no more than ten
          years apart.  The first analysis year shall be no later
          than 1996 (for NO2 areas) or four years and six months
          following the date of designation (for PM10 areas).  The
          second analysis year shall be either the attainment year
          for the area, or if the attainment year is the same as
          the first analysis year or earlier, the second analysis
          year shall be at least five years beyond the first
          analysis year.  The last year of the transportation
          plan's forecast period shall also be an analysis year.
     (2)  Define for each of the analysis years the "Baseline"
          scenario, as defined in 51.436(c), and the "Action"
          scenario, as defined in 51.436(d).
     (3)  Estimate the emissions predicted to result in each
          analysis year from travel on the transportation systems
          defined by the "Baseline" and "Action" scenarios and
          determine the difference between the two scenarios in
          regional PM10 emissions in a PM10 nonattainment area (and
          transportation-related precursors of PM10 in PM10
          nonattainment 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
          nonattainment area are a significant contributor to the
          PM10 nonattainment problem and has so notified the MPO
          and DOT) and in NOx emissions in an NO2 nonattainment
          area.  The analysis must be performed for each of the
          analysis years according to the requirements of 51.452. 
          The analysis must address the periods between the
          analysis years and the periods between 1990, the first
          milestone year (if any), and the first of the analysis
          years. Emissions in milestone years which are between the
          analysis years may be determined by interpolation.
     (4)  Demonstrate that the regional PM10 emissions and PM10
          precursor emissions, where applicable, (for PM10
          nonattainment areas) and NOx emissions (for NO2
          nonattainment areas) predicted in the 'Action' scenario
          are less than the emissions predicted from the 'Baseline'
          scenario in each analysis year, and that this can
          reasonably be expected to be true in the periods between
          the first milestone year (if any) and the analysis years.
(c)  Demonstrate that when the projects in the transportation plan
     and all other regionally significant projects expected in the
     nonattainment area are implemented, the transportation
     system's total highway and transit emissions of PM10 in a PM10
     nonattainment area (and transportation-related precursors of
     PM10 in PM10 nonattainment 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
     nonattainment area are a significant contributor to the PM10
     nonattainment problem and has so notified the MPO and DOT) and
     of NOx in an NO2 nonattainment area will not be greater than
     baseline levels, by performing a regional emissions analysis
     as follows:
     (1)  Determine the baseline regional emissions of PM10 and PM10
          precursors, where applicable (for PM10 nonattainment
          areas) and NOx (for NO2 nonattainment areas) from highway
          and transit sources.  Baseline emissions are those
          estimated to have occurred during calendar year 1990,
          unless the implementation plan revision required by
          51.396 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.
     (2)  Estimate the emissions of the applicable pollutant(s)
          from the entire transportation system, including projects
          in the transportation plan and TIP and all other
          regionally significant projects in the nonattainment
          area, according to the requirements of 51.452. 
          Emissions shall be estimated for analysis years which are
          no more than ten years apart.  The first analysis year
          shall be no later than 1996 (for NO2 areas) or four years
          and six months following the date of designation (for
          PM10 areas).  The second analysis year shall be either
          the attainment year for the area, or if the attainment
          year is the same as the first analysis year or earlier,
          the second analysis year shall be at least five years
          beyond the first analysis year.  The last year of the
          transportation plan's forecast period shall also be an
          analysis year.
     (3)  Demonstrate that for each analysis year the emissions
          estimated in paragraph (c)(2) of this section are no
          greater than baseline emissions of PM10 and PM10
          precursors, where applicable (for PM10 nonattainment
          areas) or NOx (for NO2 nonattainment areas) from highway
          and transit sources.

51.444   Criteria and procedures:  Interim period reductions for
          PM10 and NO2 areas (TIP).

(a)  A TIP must contribute to emission reductions or must not
     increase emissions in PM10 and NO2 nonattainment areas.  This
     criterion applies only during the interim and transitional
     periods.  It applies to the net effect on emissions of all
     projects contained in a new or revised TIP.  This criterion
     may be satisfied if the requirements of either paragraph (b)
     or paragraph (c) of this section are met.
(b)  Demonstrate that implementation of the plan and TIP and all
     other regionally significant projects expected in the
     nonattainment area will contribute to reductions in emissions
     of PM10 in a PM10 nonattainment area (and transportation-
     related precursors of PM10 in PM10 nonattainment 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 nonattainment area are a significant contributor to
     the PM10 nonattainment problem and has so notified the MPO and
     DOT) and of NOx in an NO2 nonattainment area, by performing a
     regional emissions analysis as follows:
     (1)  Determine the analysis years for which emissions are to
          be estimated, according to the requirements of
          51.442(b)(1).
     (2)  Define for each of the analysis years the "Baseline"
          scenario, as defined in 51.438(c), and the "Action"
          scenario, as defined in 51.438(d).
     (3)  Estimate the emissions predicted to result in each
          analysis year from travel on the transportation systems
          defined by the "Baseline" and "Action" scenarios as
          required by 51.442(b)(3), and make the demonstration
          required by  51.442(b)(4).
(c)  Demonstrate that when the projects in the transportation plan
     and TIP and all other regionally significant projects expected
     in the area are implemented, the transportation system's total
     highway and transit emissions of PM10 in a PM10 nonattainment
     area (and transportation-related precursors of PM10 in PM10
     nonattainment 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 nonattainment area are a
     significant contributor to the PM10 nonattainment problem and
     has so notified the MPO and DOT) and of NOx in an NO2
     nonattainment area will not be greater than baseline levels,
     by performing a regional emissions analysis as required by
     51.442(c)(1)-(3).

51.446   Criteria and procedures:  Interim period reductions for
          PM10 and NO2 areas (project not from a plan and TIP).

A transportation project which is not from a conforming
transportation plan and TIP must contribute to emission reductions
or must not increase emissions in PM10 and NO2 nonattainment areas. 
This criterion applies during the interim and transitional periods
only.  This criterion is met if a regional emissions analysis is
performed which meets the requirements of 51.442 and which
includes the transportation plan and project in the 'Action'
scenario.  If the project which is not from a conforming
transportation plan and TIP is a modification of a project
currently in the transportation plan or TIP, and 51.442(b) is used
to demonstrate satisfaction of this criterion, 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.

51.448   Transition from the interim period to the control
          strategy period.

(a)  Areas which submit a control strategy implementation plan
     revision after November 24, 1993.
     (1)  The transportation plan and TIP must be demonstrated to
          conform according to transitional period criteria and
          procedures by one year from the date the Clean Air Act
          requires submission of such control strategy
          implementation plan revision.  Otherwise, the conformity
          status of the transportation plan and TIP will lapse, and
          no new project-level conformity determinations may be
          made.
          (i)  The conformity of new transportation plans and TIPs
               may be demonstrated according to Phase II interim
               period criteria and procedures for 90 days
               following submission of the control strategy
               implementation plan revision, provided the
               conformity of such transportation plans and TIPs is
               redetermined according to transitional period
               criteria and procedures as required in paragraph
               (a)(1) of this section.
          (ii) Beginning 90 days after submission of the control
               strategy implementation plan revision, new
               transportation plans and TIPs shall demonstrate
               conformity according to  transitional period
               criteria and procedures.
     (2)  If EPA disapproves the submitted control strategy
          implementation plan revision and so notifies the State,
          MPO, and DOT, which initiates the sanction process under
          Clean Air Act sections 179 or 110(m), the conformity
          status of the transportation plan and TIP shall lapse 120
          days after EPA's disapproval, and no new project-level
          conformity determinations may be made.  No new
          transportation plan, TIP, or project may be found to
          conform until another control strategy implementation
          plan revision is submitted and conformity is demonstrated
          according to transitional period criteria and procedures.
     (3)  Notwithstanding paragraph (a)(2) of this section, if EPA
          disapproves the submitted control strategy implementation
          plan revision but determines that the control strategy
          contained in the revision would have been considered
          approvable with respect to requirements for emission
          reductions if all committed measures had been submitted
          in enforceable form as required by Clean Air Act
          110(a)(2)(A), the provisions of paragraph (a)(1) of this
          section shall apply for 12 months following the date of
          disapproval.  The conformity status of the transportation
          plan and TIP shall lapse 12 months following the date of
          disapproval unless another control strategy
          implementation plan revision is submitted to EPA and
          found to be complete.
(b)  Areas which have not submitted a control strategy
     implementation plan revision.
     (1)  For areas whose Clean Air Act deadline for submission of
          the control strategy implementation plan revision is
          after November 24, 1993 and EPA has notified the State,
          MPO, and DOT of the State's failure to submit a control
          strategy implementation plan revision, which initiates
          the sanction process under Clean Air Act sections 179 or
          110(m):
          (i)  No new transportation plans or TIPs may be found to
               conform beginning 120 days after the Clean Air Act
               deadline; and
          (ii) The conformity status of the transportation plan
               and TIP shall lapse one year after the
               Clean Air Act deadline, and no new project-level
               conformity determinations may be made.
     (2)  For areas whose Clean Air Act deadline for submission of
          the control strategy implementation plan was before
          November 24, 1993 and EPA has made a finding of failure
          to submit a control strategy implementation plan
          revision, which initiates the sanction process under
          Clean Air Act sections 179 or 110(m), the following apply
          unless the failure has been remedied and acknowledged by
          a letter from the EPA Regional Administrator:
          (i)  No new transportation plans or TIPs may be found to
               conform beginning March 24, 1994; and
          (ii) The conformity status of the transportation plan
               and TIP shall lapse November 25, 1994, and no new
               project-level conformity determinations may be
               made.
(c)  Areas which have not submitted a complete control strategy
     implementation plan revision.
     (1)  For areas where EPA notifies the State, MPO, and DOT
          after November 24, 1993 that the control strategy
          implementation plan revision submitted by the State is
          incomplete, which initiates the sanction process under
          Clean Air Act sections 179 or 110(m), the following apply
          unless the failure has been remedied and acknowledged by
          a letter from the EPA Regional Administrator:
          (i)  No new transportation plans or TIPs may be found to
               conform beginning 120 days after EPA's
               incompleteness finding; and
          (ii) The conformity status of the transportation plan
               and TIP shall lapse one year after the Clean Air
               Act deadline, and no new project-level conformity
               determinations may be made.
          (iii)     Notwithstanding paragraphs (c)(1)(i) and (ii)
                    of this section, if EPA notes in its
                    incompleteness finding that the submittal
                    would have been considered complete with
                    respect to requirements for emission
                    reductions if all committed measures had been
                    submitted in enforceable form as required by
                    Clean Air Act 110(a)(2)(A), the provisions of
                    paragraph (a)(1) of this section shall apply
                    for a period of 12 months following the date
                    of the incompleteness determination.  The
                    conformity status of the transportation plan
                    and TIP shall lapse 12 months following the
                    date of the incompleteness determination
                    unless another control strategy implementation
                    plan revision is submitted to EPA and found to
                    be complete.
     (2)  For areas where EPA has determined before November 24,
          1993 that the control strategy implementation plan
          revision is incomplete, which initiates the sanction
          process under Clean Air Act sections 179 or 110(m), the
          following apply unless the failure has been remedied and
          acknowledged by a letter from the EPA Regional
          Administrator:
          (i)  No new transportation plans or TIPs may be found to
               conform beginning March 24, 1994; and
          (ii) The conformity status of the transportation plan
               and TIP shall lapse November 25, 1994, and no new
               project-level conformity determinations may be
               made.
          (iii)     Notwithstanding paragraphs (c)(2)(i) and (ii)
                    of this section, if EPA notes in its
                    incompleteness finding that the submittal
                    would have been considered complete with
                    respect to requirements for emission
                    reductions if all committed measures had been
                    submitted in enforceable form as required by
                    Clean Air Act 110(a)(2)(A), the provisions of
                    paragraph (d)(1) of this section shall apply
                    for a period of 12 months following the date
                    of the incompleteness determination.  The
                    conformity status of the transportation plan
                    and TIP shall lapse 12 months following the
                    date of the incompleteness determination
                    unless another control strategy implementation
                    plan revision is submitted to EPA and found to
                    be complete.
(d)  Areas which submitted a control strategy implementation plan
     before November 24, 1993.
     (1)  The transportation plan and TIP must be demonstrated to
          conform according to transitional period criteria and
          procedures by November 25, 1994.  Otherwise, their
          conformity status will lapse, and no new project-level
          conformity determinations may be made.
          (i)  The conformity of new transportation plans and TIPs
               may be demonstrated according to Phase II interim
               period criteria and procedures until February 24,
               1994, provided the conformity of such
               transportation plans and TIPs is redetermined
               according to transitional period criteria and
               procedures as required in paragraph (d)(1) of this
               section.
          (ii) Beginning February 22, 1994, new transportation
               plans and TIPs shall demonstrate conformity
               according to transitional period criteria and
               procedures.
     (2)  If EPA has disapproved the most recent control strategy
          implementation plan submission, the conformity status of
          the transportation plan and TIP shall lapse March 24,
          1994, and no new project-level conformity determinations
          may be made.  No new transportation plans, TIPs, or
          projects may be found to conform until another control
          strategy implementation plan revision is submitted and
          conformity is demonstrated according to transitional
          period criteria and procedures.
     (3)  Notwithstanding paragraph (d)(2) of this section, if EPA
          has disapproved the submitted control strategy
          implementation plan revision but determines that the
          control strategy contained in the revision would have
          been considered approvable with respect to requirements
          for emission reductions if all committed measures had
          been submitted in enforceable form as required by Clean
          Air Act 110(a)(2)(A), the provisions of paragraph (d)(1)
          of this section shall apply for 12 months following
          November 24, 1993.  The conformity status of the
          transportation plan and TIP shall lapse 12 months
          following November 24, 1993 unless another control
          strategy implementation plan revision is submitted to EPA
          and found to be complete.
(e)  Projects.
     If the currently conforming transportation plan and TIP have
     not been demonstrated to conform according to transitional
     period criteria and procedures, the requirements of paragraphs
     (e)(1) and (2) of  this section must be met.
     (1)  Before a FHWA/FTA project which is regionally significant
          and increases single-occupant vehicle capacity (a new
          general purpose highway on a new location or adding
          general purpose lanes) may be found to conform, the State
          air agency must be consulted on how the emissions which
          the existing transportation plan and TIP's conformity
          determination estimates for the "Action" scenario (as
          required by 51.436 - 51.446) compare to the motor
          vehicle emissions budget in the implementation plan
          submission or the projected motor vehicle emissions
          budget in the implementation plan under development.
     (2)  In the event of unresolved disputes on such project-level
          conformity determinations, the State air agency may
          escalate the issue to the Governor consistent with the
          procedure in 51.402(d), which applies for any State air
          agency comments on a conformity determination.
(f)  Redetermination of conformity of the existing transportation
     plan and TIP according to the transitional period criteria and
     procedures.
     (1)  The redetermination of the conformity of the existing
          transportation plan and TIP according to transitional
          period criteria and procedures (as required by paragraphs
          (a)(1) and (d)(1) of this section) does not require new
          emissions analysis and does not have to satisfy the
          requirements of 51.412 and 51.414 if:
          (i)  The control strategy implementation plan revision
               submitted to EPA uses the MPO's modeling of the
               existing transportation plan and TIP for its
               projections of motor vehicle emissions; and
          (ii) The control strategy implementation plan does not
               include any transportation projects which are not
               included in the transportation plan and TIP.
     (2)  A redetermination of conformity as described in paragraph
          (f)(1) of this section is not considered a conformity
          determination for the purposes of 51.400(b)(4) or
          51.400(c)(4) regarding the maximum intervals between
          conformity determinations.  Conformity must be determined
          according to all the applicable criteria and procedures
          of 51.410 within three years of the last determination
          which did not rely on paragraph (f)(1) of this section.
(g)  Ozone nonattainment areas.
     (1)  The requirements of paragraph (b)(1) of this section
          apply if a serious or above ozone nonattainment area has
          not submitted the implementation plan revisions which
          Clean Air Act 182(c)(2)(A) and 182(c)(2)(B) require to
          be submitted to EPA November 15, 1994, even if the area
          has submitted the implementation plan revision which
          Clean Air Act 182(b)(1) requires to be submitted to EPA
          November 15, 1993.
     (2)  The requirements of paragraph (b)(1) of this section
          apply if a moderate ozone nonattainment area which is
          using photochemical dispersion modeling to demonstrate
          the "specific annual reductions as necessary to attain"
          required by Clean Air Act 182(b)(1), and which has 
          permission from EPA to delay submission of such
          demonstration until November 15, 1994, does not submit
          such demonstration by that date.  The requirements of
          paragraph (b)(1) of this section apply in this case even
          if the area has submitted the 15% emission reduction
          demonstration required by Clean Air Act 182(b)(1).
     (3)  The requirements of paragraph (a) of this section apply
          when the implementation plan revisions required by Clean
          Air Act 182(c)(2)(A) and 182(c)(2)(B) are submitted.
(h)  Nonattainment areas which are not required to demonstrate
     reasonable further progress and attainment.  If an area listed
     in 51.464 submits a control strategy implementation plan
     revision, the requirements of paragraphs (a) and (e) of this
     section apply.  Because the areas listed in 51.464 are not
     required to demonstrate reasonable further progress and
     attainment and therefore have no Clean Air Act deadline, the
     provisions of paragraph (b) of this section do not apply to
     these areas at any time.
     (i)  Maintenance plans.  If a control strategy implementation
          plan revision is not submitted to EPA but a maintenance
          plan required by Clean Air Act 175A is submitted to EPA,
          the requirements of paragraph (a) or (d) of this section
          apply, with the maintenance plan submission treated as a
          "control strategy implementation plan revision" for the
          purposes of those requirements.

51.450   Requirements for adoption or approval of projects by
          recipients of funds designated under title 23 U.S.C. or
          the Federal Transit Act. 

No recipient of federal funds designated under title 23 U.S.C. or
the Federal Transit Act shall adopt or approve a regionally
significant highway or transit project, regardless of funding
source, unless there is a currently conforming transportation plan
and TIP consistent with the requirements of 51.420 and the
requirements of one of the following paragraphs (a) through (e) are
met:

(a)  The project comes from a conforming plan and program
     consistent with the requirements of 51.422;
(b)  The project is included in the regional emissions analysis
     supporting the currently conforming TIP's conformity
     determination, even if the project is not strictly "included"
     in the TIP for the purposes of MPO project selection or
     endorsement, and the project's design concept and scope have
     not changed significantly from those which were included in
     the regional emissions analysis, or in a manner which would
     significantly impact use of the facility;
(c)  During the control strategy or maintenance period, the project
     is consistent with the motor vehicle emissions budget(s) in
     the applicable implementation plan consistent  with the
     requirements of 51.432;
(d)  During Phase II of the interim period, the project contributes
     to emissions reductions or does not increase emissions
     consistent with the requirements of 51.440 (in ozone and CO
     nonattainment areas) or 51.446 (in PM10 and NO2 nonattainment
     areas); or
(e)  During the transitional period, the project satisfies the
     requirements of both paragraphs (c) and (d) of this section.

51.452   Procedures for determining regional transportation-
          related emissions.

(a)  General requirements.
     (1)  The regional emissions analysis for the transportation
          plan, TIP, or project not from a conforming plan and TIP
          shall include all regionally significant projects
          expected in the nonattainment or maintenance area,
          including 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 51.402.  Projects which are not regionally
          significant are not required to be explicitly modeled,
          but VMT from such projects must be estimated in
          accordance with reasonable professional practice.  The
          effects of TCMs and similar projects that are not
          regionally significant may also be estimated in
          accordance with reasonable professional practice.
     (2)  The emissions analysis may not include for emissions
          reduction credit any TCMs which have been delayed beyond
          the scheduled date(s) until such time as implementation
          has been assured.  If the TCM 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 regulation in order to be
          implemented may not be included in the emissions analysis
          unless the regulation is already adopted by the enforcing
          jurisdiction.  Adopted regulations are required for
          demand management strategies for reducing emissions which
          are not specifically identified in the applicable
          implementation plan, and for control programs which are
          external to the transportation system itself, such as
          tailpipe or evaporative emission standards, limits on
          gasoline volatility, inspection and maintenance programs,
          and oxygenated or reformulated gasoline or diesel fuel. 
          A regulatory program may also be considered to be adopted
          if an opt-in to a Federally enforced program has been
          approved by EPA, if EPA has promulgated the program (if
          the control program is a Federal responsibility, such as
          tailpipe standards), or if 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)  Notwithstanding paragraph (a)(3) of this section, during
          the transitional period, control measures or programs
          which are committed to in an implementation plan
          submission as described in 51.428 - 51.432, but which
          has not received final EPA action in the form of a
          finding of incompleteness, approval, or disapproval may
          be assumed for emission reduction credit for the purpose
          of demonstrating that the requirements of 51.428 -
          51.432 are satisfied.
     (5)  A regional emissions analysis for the purpose of
          satisfying the requirements of 51.436 - 51.440 may
          account for the programs in paragraph (a)(4) of this
          section, but the same assumptions about these programs
          shall be used for both the "Baseline" and "Action"
          scenarios.
(b)  Serious, severe, and extreme ozone nonattainment areas and
     serious carbon monoxide areas after January 1, 1995.
     Estimates of regional transportation-related emissions used to
     support conformity determinations must be made according to
     procedures which meet the requirements in paragraphs (b)(1)
     through (5) of this section.
     (1)  A network-based transportation demand model or models
          relating travel demand and transportation system
          performance to land-use patterns, population
          demographics, employment, transportation infrastructure,
          and transportation policies must be used to estimate
          travel within the metropolitan planning area of the
          nonattainment area.  Such a model shall possess the
          following attributes:
          (i)  The modeling methods and the functional
               relationships used in the model(s) shall in all
               respects be in accordance with acceptable
               professional practice, and reasonable for purposes
               of emission estimation;
          (ii) The network-based model(s) must be validated
               against ground counts for a base year that is not
               more than 10 years prior to the date of the
               conformity determination.  Land use, population,
               and other inputs must be based on the best
               available information and appropriate to the
               validation base year;
          (iii)     For peak-hour or peak-period traffic
                    assignments, a capacity sensitive assignment
                    methodology must be used;
          (iv) Zone-to-zone travel times used to distribute trips
               between origin and destination pairs must be in
               reasonable agreement with the travel times which
               result from the process of assignment of trips to
               network links.  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;
          (v)  Free-flow speeds on network links shall be based on
               empirical observations;
          (vi) Peak and off-peak travel demand and travel times
               must be provided;
          (vii)     Trip distribution and mode choice must be
                    sensitive to pricing, where pricing is a
                    significant factor, if the network model is
                    capable of such determinations and the
                    necessary information is available;
          (viii)    The model(s) must utilize and document a
                    logical correspondence between the assumed
                    scenario of land development and use and the
                    future transportation system for which
                    emissions are being estimated.  Reliance on a
                    formal land-use model is not specifically
                    required but is encouraged;
          (ix) A dependence of trip generation on the
               accessibility of destinations via the
               transportation system (including pricing) is
               strongly encouraged but not specifically required,
               unless the network model is capable of such
               determinations and the necessary information is
               available;
          (x)  A dependence of regional economic and population
               growth on the accessibility of destinations via the
               transportation system is strongly encouraged but
               not specifically required, unless the network model
               is capable of such determinations and the necessary
               information is available; and
          (xi) Consideration of emissions increases from
               construction-related congestion is not specifically
               required.
     (2)  Highway Performance Monitoring System (HPMS) estimates of
          vehicle miles traveled shall be considered the primary
          measure of vehicle miles traveled 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.  A factor (or factors) shall be developed to
          reconcile and calibrate the network-based model estimates
          of vehicle miles traveled in the base year of its
          validation to the HPMS estimates for the same period, and
          these factors shall be applied to model estimates of
          future vehicle miles traveled.  In this factoring
          process, consideration will be given to differences in
          the facility coverage of the HPMS and the modeled network
          description.  Departure from these procedures is
          permitted with the concurrence of DOT and EPA.
     (3)  Reasonable methods shall be used to estimate
          nonattainment area vehicle travel on off-network roadways
          within the urban transportation planning area, and on
          roadways outside the urban transportation planning area.
     (4)  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 model.
     (5)  Ambient temperatures shall be consistent with those used
          to establish the emissions budget in the applicable
          implementation plan.  Factors other than temperatures,
          for example the fraction of travel in a hot  stabilized
          engine mode, may be modified after interagency
          consultation according to 51.402 if the newer estimates
          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.
(c)  Areas which are not serious, severe, or extreme  ozone
     nonattainment areas or serious carbon monoxide areas, or
     before January 1, 1995.
     (1)  Procedures which satisfy some or all of the requirements
          of paragraph (a) of this section shall be used in all
          areas not subject to paragraph (a) of this section in
          which those procedures have been the previous practice of
          the MPO.
     (2)  Regional emissions may be estimated by methods which do
          not explicitly or comprehensively account for the
          influence of land use and transportation infrastructure
          on vehicle miles traveled and traffic speeds and
          congestion.  Such methods must account for VMT growth by
          extrapolating historical VMT or projecting future VMT by
          considering growth in population and historical growth
          trends for vehicle miles travelled per person.  These
          methods must also consider future economic activity,
          transit alternatives, and transportation system policies.
(d)  Projects not from a conforming plan and TIP in isolated rural
     nonattainment and maintenance areas.  This paragraph applies
     to any nonattainment or maintenance area or any 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
     (because the nonattainment or maintenance area or portion
     thereof does not contain a metropolitan planning area or
     portion of a metropolitan planning area and is not part of a
     Metropolitan Statistical Area or Consolidated Metropolitan
     Statistical Area which is or contains a nonattainment or
     maintenance area).
     (1)  Conformity demonstrations for projects in these areas may
          satisfy the requirements of 51.432, 51.440, and 51.446
          with one regional emissions analysis which includes all
          the regionally significant projects in the nonattainment
          or maintenance area (or portion thereof).
     (2)  The requirements of 51.432 shall be satisfied according
          to the procedures in 51.432(c), with references to the
          "transportation plan" taken to mean the statewide
          transportation plan.
     (3)  The requirements of 51.440 and 51.446 which reference
          "transportation plan" or "TIP" shall be taken to mean
          those projects in the statewide transportation plan or
          statewide TIP which are in the nonattainment or
          maintenance area (or portion thereof).
     (4)  The requirement of 51.450(b) shall be satisfied if:
          (i)  The project is included in the regional emissions
               analysis which includes all regionally significant
               highway and transportation projects in the
               nonattainment or maintenance area (or portion
               thereof) and supports the most recent conformity
               determination made according to the requirements of
               51.432, 51.440, or 51.446 (as modified by
               paragraphs (d)(2) and (d)(3) of this section), as
               appropriate for the time period and pollutant; and
          (ii) The project's design concept and scope have not
               changed significantly from those which were
               included in the  regional emissions analysis, or in
               a manner which would significantly impact use of
               the facility.
(e)  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.

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

(a)  In the following cases, CO hot-spot analyses must be based on
     the applicable air quality models, data bases, and other
     requirements specified in 40 CFR part 51 Appendix W
     ("Guideline on Air Quality Models (Revised)" (1988),
     supplement A (1987) and supplement B (1993), EPA publication
     no. 450/2-78-027R), unless, after the interagency consultation
     process described in 51.402 and with the approval of the EPA
     Regional Administrator, these models, data bases, and other
     requirements are determined to be inappropriate:
     (1)  For projects in or affecting locations, areas, or
          categories of sites which are identified in the
          applicable implementation plan as sites of current
          violation or possible current violation;
     (2)  For those intersections 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 a new
          project in the vicinity;
     (3)  For any project involving or affecting any of the
          intersections which the applicable implementation plan
          identifies as the top three intersections in the
          nonattainment or maintenance area based on the highest
          traffic volumes;
     (4)  For any project involving or affecting any of the
          intersections which the applicable implementation plan
          identifies as the top three intersections in the
          nonattainment or maintenance area based on the worst
          Level-of-Service; and
     (5)  Where use of the "Guideline" models is practicable and
          reasonable given the potential for violations.
(b)  In cases other than those described in paragraph (a) of this
     section, other quantitative methods may be used if they
     represent reasonable and common professional practice.
(c)  CO hot-spot analyses must include the entire project, and may
     be performed only after the major design features which will
     significantly impact CO concentrations  have been identified. 
     The background concentration can be estimated using the ratio
     of future to current traffic multiplied by the ratio of future
     to current emission factors.
(d)  PM10 hot-spot analysis must be performed for projects which are
     located at sites at which violations have been verified by
     monitoring, and at sites which have essentially identical
     vehicle and roadway emission and dispersion characteristics
     (including sites near one at which a violation has been
     monitored).  The projects which require PM-10 hot-spot
     analysis shall be determined through the interagency
     consultation process required in 51.402.  In PM-10
     nonattainment and maintenance areas, new or expanded bus and
     rail terminals and transfer points which increase the number
     of diesel vehicles congregating at a single location require
     hot-spot analysis.  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.  The requirements
     of this paragraph for quantitative hot-spot analysis will not
     take effect until EPA releases modeling guidance on this
     subject and announces in the Federal Register that these
     requirements are in effect.
(e)  Hot-spot analysis assumptions must be consistent with those in
     the regional emissions analysis for those inputs which are
     required for both analyses.
(f)  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 the implementation
     of such measures, as required by 51.458(a).
(g)  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.

51.456   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 emission 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 a SIP revision which assigns some or all of this safety
     margin to highway and transit mobile sources for the purposes
     of conformity.  Such a SIP 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, without a SIP revision or a SIP
     which establishes 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 SIP
     may establish motor vehicle emissions budgets for each MPO, or
     else the MPOs must collectively make a conformity
     determination for the entire nonattainment area. 

51.458   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 Act, 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 making conformity
     determinations 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 included in the project design
     concept and scope which is used in the regional emissions
     analysis required by 51.428 - 51.432 and 51.436 - 51.440
     or used in the project-level hot-spot analysis required by
     51.424 and 51.434.
(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 51.396 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)  During the control strategy and maintenance periods, 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 requirements of 51.424, 51.428, and
     51.430 are satisfied without the mitigation or control
     measure, and so notifies the agencies involved in the
     interagency consultation process required under 51.402.  The
     MPO and DOT must confirm that the transportation plan and TIP
     still satisfy the requirements of 51.428 and 51.430 and that
     the project still satisfies the requirements of 51.424, and
     therefore that the conformity determinations for the
     transportation plan, TIP, and project are still valid.

51.460   Exempt projects.

Notwithstanding the other requirements of this subpart, highway and
transit projects of the types listed in Table 2 are exempt from the
requirement that a conformity determination be made.  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 is not exempt if the MPO in consultation
with other agencies (see 51.402(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.  - 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 vehicles1
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 fleet1
Construction of new bus or rail storage/maintenance facilities
categorically excluded in 23 CFR 771
Table 2 (con't)

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
Advance land acquisitions (23 CFR 712 or 23 CFR 771)
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

     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.

51.462   Projects exempt from regional emissions analyses.

Notwithstanding the other requirements of this subpart, highway and
transit projects of the types listed in Table 3 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 is not exempt from regional
emissions analysis if the MPO in consultation with other agencies
(see 51.402(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 potential regional impacts for any reason.

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

51.464   Special provisions for nonattainment areas which are not
          required to demonstrate reasonable further progress and
          attainment.

(a)  Application.
     This section applies in the following areas:
     (1)  Rural transport ozone nonattainment areas;
     (2)  Marginal ozone areas;
     (3)  Submarginal ozone areas;
     (4)  Transitional ozone areas;
     (5)  Incomplete data ozone areas;
     (6)  Moderate CO areas with a design value of 12.7 ppm or
          less; and
     (7)  Not classified CO areas.
(b)  Default conformity procedures.
     The criteria and procedures in 51.436 - 51.440 will remain
     in effect throughout the control strategy period for
     transportation plans, TIPs, and projects (not from a
     conforming plan and TIP) in lieu of the procedures in 51.428
     - 51.432, except as otherwise provided in paragraph (c) of
     this section.
(c)  Optional conformity procedures.
     The State or MPO may voluntarily develop an attainment
     demonstration and corresponding motor vehicle emissions budget
     like those required in areas with higher nonattainment
     classifications.  In this case, the State must submit an
     implementation plan revision which contains that budget and
     attainment demonstration.  Once EPA has approved this
     implementation plan revision, the procedures in 51.428 -
     51.432 apply in lieu of the procedures in 51.436 - 51.440.







                            EPA Summary of the


                      Transportation Conformity Rule




                    Section 176 of the Clean Air Act as
                             Amended in 1990


                        Requirements for Conformity