Transportation Conformity Rule Amendments Highlights

July 1, 2004

This rule finalizes two separate proposals made by the U.S. Environmental Protection Agency (EPA) to address the new air quality standards (68 FR 62690, November 5, 2003) and the March 1999 court decision (68 FR 38974, June 30, 2003). The rule also finalizes a number of miscellaneous provisions that were also included in the two proposals to clarify and streamline the transportation conformity process. Highlights of the rule include:

• Metropolitan transportation plans and TIPs in new nonattainment areas must be found to conform against the new standard by 1-year after the effective date of designation - by June 15, 2005 for 8-hour ozone areas. In addition, conformity for the 1-hour ozone standard will no longer apply in existing 1-hour ozone nonattainment and maintenance once the 1-hour standard is revoked. For most areas, this will be on June 15, 2005.
• 2002 is established as the baseline year for interim conformity tests for 8-hour ozone and PM_2.5 areas.
• A "build-no-greater-than-no-build" test is created for certain ozone and CO areas of lower classification and all PM₁₀, PM_2.5, and NO₂ areas. Instead of requiring that the build emissions be lower than the no-build scenario, these areas will now be able to determine conformity if the build emissions are equal to or lower than the no-build emissions.
• Prior to 8-hour budgets being established, all areas with adequate or approved 1-hour budgets must use them to demonstrate conformity, unless it is determined through interagency consultation that using the interim emissions tests is more appropriate.

  NOTE:On October 20, 2006, the DC Circuit U.S. Court of Appeals vacated 40 CFR 93.109(e)(2)(v). 8-hour ozone areas that do not have adequate or approved 8-hour budgets can no longer utilize this provision to use the interim emissions tests instead of their 1-hour budgets to demonstrate conformity. Please see: (Circuit Court Ruling)

• Prior to PM_2.5 budgets being established, PM_2.5 areas must demonstrate conformity by meeting either the "build-no-greater-than-no-build test" or the "no-greater-than-2002 test."
• Conformity analyses in PM_2.5 areas only need to include re-entrained road if the EPA Regional Administrator or the State air quality agency determines that re-entrained road dust is a significant contributor to the PM_2.5 regional air quality problem.
• Conformity analyses in PM_2.5 areas only need to include construction-related fugitive dust from highway or transit projects if the SIP identifies construction dust as a significant contributor to the regional air quality problem.
• EPA is not finalizing conformity requirements associated with PM_2.5 precursors or hot-spots at this time. EPA will be issuing a supplemental notice of proposed rulemaking to address additional hot-spot options. EPA intends to finalize requirements to address precursors and hot-spots by the time PM_2.5 designations are effective.
• The conformity rule is being revised to reflect current procedures that have already been put into place to reflect the March 1999 court decision.
• The requirement that conformity be determined within 18 months of approval of a SIP that adds, deletes, or changes a TCM is being eliminated, and other 18-month clocks only need to be satisfied when a conformity determination has not already been made using the same budget.
• Conformity determinations can be based on the latest planning assumptions that are available at the time the conformity analysis begins, as determined through interagency consultation, rather than at the time of FHWA/FTA's conformity determination.