(a) The transportation plan, TIP, and project not from a conforming transportation plan and TIP must satisfy the interim emissions test(s) as described in §93.109(c) through (g). This criterion applies to the net effect of the action (transportation plan, TIP, or project not from a conforming plan and TIP) on motor vehicle emissions from the entire transportation system.

(b) Ozone areas. The requirements of this paragraph apply to all ozone NAAQS areas, except for certain requirements as indicated. This criterion may be met:

(1) In moderate and above ozone nonattainment areas that are subject to the reasonable further progress requirements of CAA section 182(b)(1) if a regional emissions analysis that satisfies the requirements of §93.122 and paragraphs (g) through (j) of this section demonstrates that for each analysis year and for each of the pollutants described in paragraph (f) of this section:

(i) The emissions predicted in the “Action” scenario are less than the emissions predicted in the “Baseline” scenario, and this can be reasonably expected to be true in the periods between the analysis years; and

(ii) The emissions predicted in the “Action” scenario are lower than emissions in the baseline year for that NAAQS as described in paragraph (e) of this section by any nonzero amount.

(2) In marginal and below ozone nonattainment areas and other ozone nonattainment areas that are not subject to the reasonable further progress requirements of CAA section 182(b)(1) if a regional emissions analysis that satisfies the requirements of §93.122 and paragraphs (g) through (j) of this section demonstrates that for each analysis year and for each of the pollutants described in paragraph (f) of this section:

(i) The emissions predicted in the “Action” scenario are not greater than the emissions predicted in the “Baseline” scenario, and this can be reasonably expected to be true in the periods between the analysis years; or

(ii) The emissions predicted in the “Action” scenario are not greater than emissions in the baseline year for that NAAQS as described in paragraph (e) of this section.

(c) CO areas. This criterion may be met:

(1) In moderate areas with design value greater than 12.7 ppm and serious CO nonattainment areas that are subject to CAA section 187(a)(7) if a regional emissions analysis that satisfies the requirements of §93.122 and paragraphs (g) through (j) of this section demonstrates that for each analysis year and for each of the pollutants described in paragraph (f) of this section:

(i) The emissions predicted in the “Action” scenario are less than the emissions predicted in the “Baseline” scenario, and this can be reasonably expected to be true in the periods between the analysis years; and

(ii) The emissions predicted in the “Action” scenario are lower than emissions in the baseline year for that NAAQS as described in paragraph (e) of this section by any nonzero amount.

(2) In moderate areas with design value less than 12.7 ppm and not classified CO nonattainment areas if a regional emissions analysis that satisfies the requirements of §93.122 and paragraphs (g) through (j) of this section demonstrates that for each analysis year and for each of the pollutants described in paragraph (f) of this section:

(i) The emissions predicted in the “Action” scenario are not greater than the emissions predicted in the “Baseline” scenario, and this can be reasonably expected to be true in the periods between the analysis years; or

(ii) The emissions predicted in the “Action” scenario are not greater than emissions in the baseline year for that NAAQS as described in paragraph (e) of this section.

(d) PM2.5, PM10, and NO2 areas. This criterion may be met in PM2.5, PM10, and NO2 nonattainment areas if a regional emissions analysis that satisfies the requirements of §93.122 and paragraphs (g) through (j) of this section demonstrates that for each analysis year and for each of the pollutants described in paragraph (f) of this section, one of the following requirements is met:

(1) The emissions predicted in the “Action” scenario are not greater than the emissions predicted in the “Baseline” scenario, and this can be reasonably expected to be true in the periods between the analysis years; or

(2) The emissions predicted in the “Action” scenario are not greater than emissions in the baseline year for that NAAQS as described in paragraph (e) of this section.

(e) Baseline year for various NAAQS. The baseline year is defined as follows:

(1) 1990, in areas designated nonattainment for the 1990 CO NAAQS or the 1990 NO2 NAAQS.

(2) 1990, in areas designated nonattainment for the 1990 PM10 NAAQS, unless the conformity implementation plan revision required by §51.390 of this chapter defines the baseline emissions for a PM10 area to be those occurring in a different calendar year for which a baseline emissions inventory was developed for the purpose of developing a control strategy implementation plan.

(3) 2002, in areas designated nonattainment for the 1997 ozone NAAQS or 1997 PM2.5 NAAQS.

(4) The most recent year for which EPA's Air Emission Reporting Rule (40 CFR Part 51, Subpart A) requires submission of on-road mobile source emissions inventories as of the effective date of designations, in areas designated nonattainment for a NAAQS that is promulgated after 1997.

(f) Pollutants. The regional emissions analysis must be performed for the following pollutants:

(1) VOC in ozone areas;

(2) NOX in ozone areas, unless the EPA Administrator determines that additional reductions of NOX would not contribute to attainment;

(3) CO in CO areas;

(4) PM10 in PM10 areas;

(5) VOC and/or NOX in PM10 areas if the EPA Regional Administrator or the director of the State air agency has made a finding that one or both of such precursor emissions from within the area are a significant contributor to the PM10 nonattainment problem and has so notified the MPO and DOT;

(6) NOX in NO2 areas;

(7) PM2.5 in PM2.5 areas;

(8) Reentrained road dust in PM2.5 areas only if the EPA Regional Administrator or the director of the State air agency has made a finding that emissions from reentrained road dust within the area are a significant contributor to the PM2.5 nonattainment problem and has so notified the MPO and DOT;

(9) NOX in PM2.5 areas, unless the EPA Regional Administrator and the director of the State air agency have made a finding that emissions of NOX from within the area are not a significant contributor to the PM2.5 nonattainment problem and has so notified the MPO and DOT; and

(10) VOC, SO2 and/or ammonia in PM2.5 areas if the EPA Regional Administrator or the director of the State air agency has made a finding that any of such precursor emissions from within the area are a significant contributor to the PM2.5 nonattainment problem and has so notified the MPO and DOT.

(g) Analysis years.

(1) The regional emissions analysis must be performed for analysis years that are no more than ten years apart. The first analysis year must be no more than five years beyond the year in which the conformity determination is being made. The last year of the timeframe of the conformity determination (as described under §93.106(d)) must also be an analysis year.

(2) For areas using paragraphs (b)(2)(i), (c)(2)(i), and (d)(1) of this section, a regional emissions analysis that satisfies the requirements of §93.122 and paragraphs (g) through (j) of this section would not be required for analysis years in which the transportation projects and planning assumptions in the “Action” and “Baseline” scenarios are exactly the same. In such a case, paragraph (a) of this section can be satisfied by documenting that the transportation projects and planning assumptions in both scenarios are exactly the same, and consequently, the emissions predicted in the “Action” scenario are not greater than the emissions predicted in the “Baseline” scenario for such analysis years.

(3) When the timeframe of the conformity determination is shortened under §93.106(d)(2), the conformity determination must be accompanied by a regional emissions analysis (for informational purposes only) for the last year of the transportation plan.

(h) “Baseline” scenario. The regional emissions analysis required by paragraphs (b) through (e) of this section must estimate the emissions that would result from the “Baseline” scenario in each analysis year. The “Baseline” scenario must be defined for each of the analysis years. The “Baseline” scenario is the future transportation system that will result from current programs, including the following (except that exempt projects listed in §93.126 and projects exempt from regional emissions analysis as listed in §93.127 need not be explicitly considered):

(1) All in-place regionally significant highway and transit facilities, services and activities;

(2) All ongoing travel demand management or transportation system management activities; and

(3) Completion of all regionally significant projects, regardless of funding source, which are currently under construction or are undergoing right-of-way acquisition (except for hardship acquisition and protective buying); come from the first year of the previously conforming transportation plan and/or TIP; or have completed the NEPA process.

(i) “Action” scenario. The regional emissions analysis required by paragraphs (b) and (c) of this section must estimate the emissions that would result from the “Action” scenario in each analysis year. The “Action” scenario must be defined for each of the analysis years. The “Action” scenario is the transportation system that would result from the implementation of the proposed action (transportation plan, TIP, or project not from a conforming transportation plan and TIP) and all other expected regionally significant projects in the nonattainment area. The “Action” scenario must include the following (except that exempt projects listed in §93.126 and projects exempt from regional emissions analysis as listed in §93.127 need not be explicitly considered):

(1) All facilities, services, and activities in the “Baseline” scenario;

(2) Completion of all TCMs and regionally significant projects (including facilities, services, and activities) specifically identified in the proposed transportation plan which will be operational or in effect in the analysis year, except that regulatory TCMs may not be assumed to begin at a future time unless the regulation is already adopted by the enforcing jurisdiction or the TCM is identified in the applicable implementation plan;

(3) All travel demand management programs and transportation system management activities known to the MPO, but not included in the applicable implementation plan or utilizing any Federal funding or approval, which have been fully adopted and/or funded by the enforcing jurisdiction or sponsoring agency since the last conformity determination;

(4) The incremental effects of any travel demand management programs and transportation system management activities known to the MPO, but not included in the applicable implementation plan or utilizing any Federal funding or approval, which were adopted and/or funded prior to the date of the last conformity determination, but which have been modified since then to be more stringent or effective;

(5) Completion of all expected regionally significant highway and transit projects which are not from a conforming transportation plan and TIP; and

(6) Completion of all expected regionally significant non-FHWA/FTA highway and transit projects that have clear funding sources and commitments leading toward their implementation and completion by the analysis year.

(j) Projects not from a conforming transportation plan and TIP. For the regional emissions analysis required by paragraphs (b) through (e) of this section, if the project which is not from a conforming transportation plan and TIP is a modification of a project currently in the plan or TIP, the ‘Baseline’ scenario must include the project with its original design concept and scope, and the ‘Action’ scenario must include the project with its new design concept and scope.

[62 FR 43801, Aug. 15, 1997, as amended at 69 FR 40079, July 1, 2004; 70 FR 24291, May 6, 2005; 73 FR 4441, Jan. 24, 2008; 75 FR 14285, Mar. 24, 2010; 77 FR 14988, Mar. 14, 2012]