Transportation Conformity Reference Guide
Section E: Requirements for Other Areas
Chapter 13 Isolated Rural Areas
Requirements for Isolated Rural Nonattainment and Maintenance Areas
Conformity Demonstration for Projects in Isolated Rural Areas
Conformity Requirements for Isolated Rural Areas That Are Not Required to Submit SIPs
Requirements for Isolated Rural Areas Once a SIP is Submitted
Questions and Answers
Exhibit 13-1: Plan/TIP Conformity Requirements for Isolated Rural Areas
Exhibit 13-2: Conformity Tests for Isolated Rural Areas for Years After the Period Addressed in the Control Strategy SIP or Maintenance Plan
This section reviews the conformity requirements that apply to isolated rural areas. A rural area is an area with a population of less than 50,000 and due to its small size, is exempted from FHWA/FTA's metropolitan planning requirements related to the development of transportation plans and TIPs[1]. Isolated rural nonattainment and maintenance areas are areas that do not contain or are not part of any metropolitan planning area as designated under the transportation planning regulations. Isolated rural areas do not have Federally required metropolitan transportation plans or TIPs and do not have projects that are part of the emissions analysis of any MPO's metropolitan transportation plan or TIP. Projects in such areas are instead included in statewide transportation improvement programs. These areas are not "donut" areas. Donut areas are geographic areas outside a metropolitan planning area boundary, but inside the boundary of a nonattainment or maintenance area that contains any part of a metropolitan area(s). Conformity requirements for donut areas are discussed in Chapter 12. Isolated rural areas typically exhibit a less locally-oriented planning approach in which the State transportation agency takes the leading role. Transportation projects for such an area may be included in a statewide transportation plan and must be included in a statewide transportation improvement program (STIP) prior to Federal action to fund or approve such projects. Conformity determinations in isolated rural nonattainment and maintenance areas are required only when a new non-exempt FHWA/FTA project needs funding or approval. Approvals and funding for regionally significant non-Federal projects by recipients of federal funds would also require that such projects are included in a regional emissions analysis that meets the conformity rule requirements, per 40 CFR 93.121(b). Therefore, pending state or local approvals of non-federal projects may trigger the need for a regional emissions analysis meeting the budget or interim tests, even though a conformity determination is not required.
A single regional emissions analysis that includes all regionally significant projects in the nonattainment or maintenance area can be undertaken to satisfy the conformity demonstration requirements for all projects in isolated rural areas. All regionally significant projects affecting the nonattainment or maintenance area, which are contained in the statewide transportation plan and STIP, regardless of funding source, should be included in the regional emissions analysis, along with any other known regionally significant projects (e.g., local or privately funded projects). The same requirements previously summarized in Chapters 1 and Section F, Chapter 15 for projects not from a conforming plan and TIP are then applied, with the focus on the portion of the statewide plan and STIP that covers the nonattainment or maintenance area rather than a metropolitan plan/TIP. Isolated rural areas must satisfy the budget and/or interim emissions tests as other areas; before and during the time frame of submission of an adequate SIP the same requirements apply. However, isolated rural areas have a choice for how conformity is demonstrated for the years after those covered by an adequate SIP. They can use the budget test, the interim emissions test(s), or air quality modeling used in the attainment demonstration or maintenance plan.
Requirements for Isolated Rural Nonattainment and Maintenance Areas
40 CFR §93.109(l)
This paragraph applies to any nonattainment or maintenance area (or portion thereof) which does not have a metropolitan transportation plan or TIP and whose projects are not part of the emissions analysis of any MPO's metropolitan transportation plan or TIP. This paragraph does not apply to "donut" areas which are outside the metropolitan planning boundary and inside the nonattainment/maintenance area boundary.
- FHWA/FTA projects in all isolated rural nonattainment and maintenance areas must satisfy the requirements of §§93.110, 93.111, 93.112, 93.113(d), 93.116, and 93.117. Until EPA approves the control strategy implementation plan or maintenance plan for a rural CO nonattainment or maintenance area, FHWA/FTA projects must also satisfy the requirements of §93.116(b) ("Localized CO and PM10 violations [hot spots]").
- Isolated rural nonattainment and maintenance areas are subject to the budget and/or interim emissions tests as described in paragraphs (c)-(k) of this section, with the following modifications:
- When the requirements of §§93.118 and 93.119 apply to isolated rural nonattainment and maintenance areas, references to "transportation plan" or "TIP" should be taken to mean those projects in the statewide transportation plan or statewide TIP which are in the rural nonattainment or maintenance area.
- In isolated rural nonattainment and maintenance areas that are subject to §93.118, FHWA/FTA projects must be consistent with motor vehicle emissions budget(s) for the years in the time frame of the attainment demonstration or maintenance plan. For years after the attainment year (if a maintenance plan has not been submitted) or after the last year of the maintenance plan, FHWA/FTA projects must satisfy one of the following requirements:
- §93.118;
- §93.119 (including regional emissions analysis for NOx in all ozone nonattainment and maintenance areas, notwithstanding §93.119(f)(2)); or
- As demonstrated by the air quality dispersion model or other air quality modeling technique used in the attainment demonstration or maintenance plan, the FHWA/FTA project, in combination with all other regionally significant projects expected in the area in the time frame of the statewide transportation plan, must not cause or contribute to any new violation of any standard in any areas; increase the frequency or severity of any existing violation of any standard in any area; or delay timely attainment of any standard or any required interim emissions reductions or other milestones in any area. Control measures assumed in the analysis must be enforceable.
- The choice of requirements in paragraph (l)(2)(ii) of this section and the methodology used to meet the requirements of paragraph (l)(2)(ii)(C) of this section must be determined through the interagency consultation process required in §93.105(c)(1)(vii) through which the relevant recipients of title 23 U.S.C. or Federal Transit Laws funds, the local air quality agency, the State air quality agency, and the State department of transportation should reach consensus about the option and methodology selected. EPA and DOT must be consulted through this process as well. In the event of unresolved disputes, conflicts may be escalated to the Governor consistent with the procedure in §93.105(d), which applies for any State air agency comments on a conformity determination.
Conformity requirements for isolated rural nonattainment and maintenance areas are summarized in Exhibit 13-1.
Conformity Demonstration for Projects in Isolated Rural Areas
Conformity demonstrations for projects in isolated rural nonattainment and maintenance areas are based on a single regional emissions analysis that includes all regionally significant projects in the nonattainment or maintenance area. Subject to the constraints described below, the conformity requirements contained relating to the emissions budget test and/or interim emissions tests must be met, based on a regional emissions analysis of the applicable nonattainment or maintenance area portion of the statewide transportation plan and STIP. Individual project level conformity determinations may also be required as summarized in Section F, Chapter 14.
Conformity Requirements for Isolated Rural Areas That Are Not Required to Submit SIPs
These requirements apply to certain types of nonattainment areas that have not submitted a maintenance plan and are not required to submit control strategy SIPs. The areas can include the following:
- Rural ozone transport nonattainment areas,
- Marginal ozone areas,
- Moderate CO areas with a design value of 12.7 ppm or less,
- Not classified CO areas, and
- Rural PM10 or NO2 areas.
Transportation projects located in one of the above areas must be shown to not cause any new violations of the NAAQS, increase the frequency or severity of any existing violation, or delay attainment or required milestone within the nonattainment area in order to demonstrate conformity. As provided in the transportation conformity rule provisions for areas without motor vehicle emissions budgets, the interim emissions test that is applied to ensure this criterion is met can be either the build no greater than no-build test or the no-greater-than-baseline test. The emissions budget test is not applied in the above areas unless the State voluntarily submits an attainment demonstration and accompanying motor vehicle emissions budget(s). In such a case, the budget test replaces the above interim emissions test once the EPA finds the budget adequate for conformity purposes.
Requirements for Isolated Rural Areas Once a SIP is Submitted
Areas required to submit control strategy SIPs include basic (subpart 1), moderate and above ozone nonattainment areas and CO nonattainment areas classified as serious or as moderate with a design value of greater than 12.7 ppm, PM2.5 and PM10 areas. If nonattainment areas voluntarily submit SIPs or maintenance plans, they will be required to meet the emissions budget test once adequate or approved budgets are available. As described previously in Section B, if EPA declares that the submitted emissions budget is adequate, the emissions budget test is to be applied to all conformity determinations for the area.
For years after the attainment year (if no maintenance plan has been submitted) or after the last year of the maintenance plan, one of three possible conformity tests must be met for isolated rural areas. These tests are summarized in Exhibit 13-2. Under the first alternative, the area can use the last adequate budget for the budget test. (i.e., projected regional emissions must be less than or equal to the emissions budget).
Under the second alternative, the area must meet the applicable interim emissions test or tests. Under this alternative, moderate and above ozone nonattainment and maintenance areas would have to do both the build/no-build and the less-than-baseline emissions tests. Under the third alternative, air quality dispersion modeling or other air quality modeling technique (e.g. rollback modeling) previously used in the attainment demonstration or maintenance plan can be used to demonstrate that the FHWA/FTA project, in combination with all other regionally significant projects expected in the time frame of the statewide transportation plan:
40 CFR §93.109(l)(2)(ii)(C)
Must not cause or contribute to any new violation of any standard in any areas; increase the frequency or severity of any existing violation of any standard in any area; or delay timely attainment of any standard or any required interim emissions reduction or other milestones in any area. Control measures used in the analysis must be enforceable.
As specified in the rule, the test to be used and the methodology selected for air quality modeling must be determined through the interagency consultation process.
40 CFR §93.109(l)(2)(iii)
The choice of requirements in paragraph (l)(2)(iii) of this section and the methodology used to meet the requirements of paragraph (l)(2)(ii)(C) of this section must be determined through the interagency consultation process required in §93.105(c)(1)(vii) through which the relevant recipients of title 23 U..S.C. or Federal Transit Laws funds, the local air quality agency, the State air quality agency, and the State department of transportation should reach consensus about the option and methodology selected. EPA and DOT must be consulted through this process as well. In the event of unresolved disputes, conflicts may be escalated to the Governor consistent with the procedure in §93.105(d), which applies for any State air agency comments on a conformity determination.
Questions and Answers
What are the specific conformity requirements for isolated rural nonattainment and maintenance areas?
Specific conformity requirements for isolated rural nonattainment and maintenance areas are listed in 40 CFR 93.109(l).
To demonstrate conformity, a regional emissions analysis, which includes emissions from the existing transportation system and all planned non-exempt Federal and regionally significant non-Federal projects in the rural nonattainment or maintenance area is required. The subset of projects within the rural nonattainment or maintenance area must include all those projects listed in the State Transportation Improvement Program (STIP) for the subject area, along with any other known regionally significant projects (e.g., local or privately funded projects), and should be consistent with the policies and objectives embodied in the Statewide transportation plan. If the Statewide transportation plan identifies specific projects for the subject area, then the emissions analysis should include those projects as well. The emissions analysis must cover a period of 20 years, including any necessary interim analysis years. The emissions estimates from the regional analysis are subject to the conformity tests - the budget and/or interim emissions tests.
In the budget test, emissions must be less than or equal to the motor vehicle emissions budget specified in the State Implementation Plan (SIP), and found adequate or approved by EPA. If the interim emissions test is used, the applicable requirements vary, depending on the pollutant and classification (see Exhibit 13-1 above). To demonstrate conformity in the out-years (i.e., years after the period covered by the SIP), projects must satisfy the budget test, interim emissions test, or an air quality modeling test. (See 40 CFR 93.109(l) for specific requirements.)
How frequently do isolated rural areas need to do conformity?
The frequency requirements for metropolitan areas (40 CFR 93.104) do not apply in isolated rural areas. This is because they do not have transportation plans or TIPs pursuant to the metropolitan planning regulations. In isolated rural areas a conformity determination must be done only when a non-exempt federal transportation project needs approval.
Conformity in isolated rural nonattainment and maintenance areas is required when approving a federally funded project. Some projects (e.g., safety projects) are exempt from conformity altogether, and some are exempt from regional emissions analyses (See 40 CFR 93.126 - 93.128). Unlike in metropolitan areas, there are no requirements to update conformity determinations for projects in isolated rural nonattainment and maintenance areas on a 4-year cycle, or to meet other conformity triggers as required in 40 CFR §93.104.
The Clean Air Act 176(c) lists specific requirements for conformity on transportation plans and TIPs in metropolitan areas, developed pursuant to 23 USC 134. However, these requirements do not apply to projects in isolated rural nonattainment and maintenance areas because these projects are not considered as part of metropolitan plans and TIPs. Projects to be included in the regional emission analysis for isolated rural nonattainment and maintenance areas are subsets of statewide transportation plans and STIPs, and they must still demonstrate conformity according to the requirements of 40 CFR §93.118 and §93.119 (See 40 CFR 93.109(l)(2)(i).)
How does conformity apply to non-Federal projects in isolated rural nonattainment and maintenance areas?
Regionally significant non-Federal projects can only be approved and/or funded if they meet the requirements in 40 CFR 93.121(b). The regionally significant project must have been included in the regional emissions analysis supporting the most recent conformity determination for the subject area, or a new regional emissions analysis including the project and all other regionally significant projects expected in the subject area must be performed.
What is the process for determining conformity in isolated rural nonattainment and maintenance areas? Who is involved? What are the requirements for interagency consultation?
In most cases, the State DOT will be responsible for preparing and reviewing all documents for the conformity determination. An agreement should be made between the State and the local governments in isolated rural nonattainment and maintenance areas on the responsibilities for performing the regional emissions analysis.
Once the State DOT has made its conformity determination, it will then forward this information to the FHWA and the FTA, which, in consultation with the Environmental Protection Agency (EPA), must also make a conformity determination. FHWA/FTA will make a conformity determination for the subset of projects in the isolated rural nonattainment or maintenance area.
The interagency consultation process requirements (40 CFR 93.105 and 93.109(l)(2)(iii)) must be met and should be documented according to the State's Conformity SIP, or, if there is no approved conformity SIP for the area, in a Memorandum of Understanding (MOU).
What projects need to be included in a conformity analysis for an isolated rural nonattainment or maintenance area?
The conformity analysis must include all those non-exempt Federal projects listed in the State Transportation Improvement Program (STIP) for the subject area, and should be consistent with the policies and objectives embodied in the statewide transportation plan. If the Statewide transportation plan identifies specific projects for the subject area, then the emissions analysis should include those projects as well. The analysis must also include any regionally significant non-Federal projects planned for the subject area, including any known state, local or private projects.
How many years into the future do conformity determinations for isolated rural nonattainment and maintenance areas need to cover?
A minimum 20-year forecast period must be analyzed for all conformity determinations. Conformity needs to cover the forecast period of the Statewide transportation plan (consistent with 40 CFR §93.109(g), and the transportation planning statute (section 135 of Title 23, U.S.C.) requires at least a 20-year forecast period for Statewide transportation plans.
In its conformity analysis, does the rural nonattainment or maintenance area have to consider the emissions impacts of projects that may be outside the nonattainment or maintenance area but that will impact travel in that area (e.g., regionally significant projects)? If so, how is the rural nonattainment and maintenance area made aware of such projects?
As in the case of metropolitan nonattainment and maintenance areas, travel impacts of regionally significant projects that are located outside of rural nonattainment and maintenance areas, but which will have travel impacts inside those areas, should be considered in the analysis. Knowledge of such projects should be gained through appropriate interagency consultation among the participants in the planning process, including State and local transportation and air agencies, FHWA, FTA and EPA.
Do the Federal public involvement requirements apply to isolated rural nonattainment and maintenance area conformity determinations? Who will be responsible for carrying out these requirements?
Yes, public consultation procedures as outlined in 40 CFR 93.105(e) will also apply to isolated rural nonattainment and maintenance area conformity determinations. We anticipate that in most cases the State DOT is responsible for carrying out the necessary public involvement requirements for the Statewide plan and STIP, as well as other required interagency consultation processes for rural nonattainment and maintenance areas (40 CFR 93.105(e)). In addition, public involvement requirements must also met during project development according to 23 CFR 771.111(h).
Does DOT's transportation planning regulation require isolated rural areas to have transportation plans or TIPs in addition to the Statewide transportation plan and STIP?
No. There are no Federal requirements for rural areas to develop transportation plans or TIPs.
Although there are no Federal regulations that require isolated rural areas to have plans and TIPs, some isolated rural areas are required by state planning regulations to develop these documents. Can these areas incorporate their TIPs into the STIP without the need to comply with Federal statewide planning regulations?
No. All Federal projects (including those within isolated rural nonattainment and maintenance areas) must be included in the STIP, which is subject to Federal statewide planning requirements (e.g. environmental justice considerations, public involvement, consultation with elected officials, planning factor considerations, etc.). The STIP must come from a planning process that meets the requirements detailed in Section 135 of Title 23, U.S.C. as amended by SAFETEA-LU.
Does conformity of a proposed project in an isolated rural nonattainment or maintenance area need to be determined before FHWA/FTA can approve a STIP containing such project?
No. The STIP itself is not subject to conformity. Conformity of a proposed project in an isolated rural nonattainment or maintenance area must be determined prior to the first specific non-exempt project approval, which in most cases will be final NEPA approval.
Are all rural areas exempt from the motor vehicle emissions budget test?
No. Areas that have adequate or approved budgets must meet the budget test, except for certain flexibility for the years beyond the budget (see Exhibit 13-2). Areas that are required to submit control strategy SIPs are: basic (subpart 1), moderate and above ozone areas and CO areas classified as serious or as moderate with a design value of greater than 12.7 ppm, PM2.5 and PM10 areas. In addition, other areas can choose to voluntarily submit a motor vehicle emissions budget.
An isolated rural area is allowed to use the results of air quality modeling to demonstrate conformity for years after the time period addressed in the SIP. Have specific modeling procedures been developed or are they being developed for this purpose?
The type of modeling procedures to be used for a particular area must be determined through the interagency consultation process required in 40 CFR §93.105(c)(1)(vii).
How can regional emissions tests be applied to a project in a rural isolated area when no network models exist in the area?
Estimates of vehicle miles traveled (VMT) based on HPMS or locally-approved traffic counts and speed will need to be developed for vehicle travel in the area for both the baseline and action scenarios for the applicable analysis year(s). These data can then be used to generate regional emissions estimates for each scenario, which in turn will be used to perform the required motor vehicle emissions budget or interim emissions tests.
[1] 23 CFR 450
