• Air Toxics
• CMAQ
• Conformity

• Laws and Regulations
• Policy and Guidance
  • Air Quality Planning and SIPs
  • Conformity Lapse / Grace Period
  • Emissions Analysis
  • Land Use
  • Multi-Jurisdictional (Complex) Areas
  • NAAQS and Designations
  • Project Level Conformity
  • Transportation Control Measures
• Research
• Reference Material
• Models & Methodologies
• Training

Multi-Jurisdictional (Complex) Areas

The boundaries of a metropolitan planning organization (MPO) do not always correspond to the nonattainment or maintenance area boundary, nor does a nonattainment or maintenance area always contain a single MPO. In addition, a nonattainment or maintenance area boundary may encompass portions of more than one state. Also, there may be some portion of the nonattainment or maintenance area that is not included in any MPO's planning area. The following documents provide information about transportation conformity issues related to these multi-jurisdictional areas.

Policy & Guidance

• Guidance for Transportation Conformity Implementation in Multi-Jurisdictional Nonattainment and Maintenance Areas (EPA, July 2012) This document updates and supersedes EPA's 2004 "Multi-jurisdictional guidance." It describes how transportation conformity determinations are done in areas where multiple metropolitan planning organizations (MPOs), states and/or other agencies have jurisdiction in a nonattainment or maintenance area. The revised guidance is consistent with the Transportation Conformity Restructuring Rule and applies to any current and future NAAQS, including the 2008 ozone NAAQS.
• Court Decision on Transportation Conformity Rule (October 2006) - The U.S. Court of Appeals vacated a provision of the Transportation Conformity Rule (40 CFR 93.109(e)(2)(v)), a provision that allowed areas to use the interim emissions tests instead of the 1-hour budgets where the interim tests could be shown to be more appropriate for ensuring that the plan, TIP, or project would not create new violations, worsen existing violations, or delay timely attainment of the 8-hour standard, as determined through interagency consultation.
• Guidance for Creating Annual On-Road Mobile Source Emission Inventories for PM2.5 Nonattainment Areas for Use in SIPs and Conformity (August 2005) - EPA guidance on preparation of annual inventories for PM2.5 SIPs or regional conformity analyses by state and local agencies. It also addresses the possible use of the National Mobile Inventory Model (NMIM) in SIPs and conformity analyses.
• Conformity Implementation in Multi-jurisdictional Nonattainment and Maintenance Areas for Existing and New Air Quality Standards (July 2004) - EPA guidance to clarify how conformity determinations and the regional emissions analyses that support them are completed, particularly where multiple agencies or states are involved