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Air Quality Planning for Transportation Officials

Transportation Conformity

Transportation conformity, as required by the CAA, ensures that Federally-funded or approved transportation plans, programs, and projects conform to the air quality objectives established in the SIP. Transportation conformity regulations are developed by EPA, with the U.S. Department of Transportation's (DOT's) input and concurrence. The U.S. DOT (through the FHWA and FTA) is responsible for implementing the conformity regulation in nonattainment and maintenance areas. EPA has a consultative role in the analysis and findings that are required. In terms of transportation plans and transportation improvement programs (TIPs), FHWA/FTA's joint conformity determination is based on a quantitative demonstration that projected motor vehicle emissions from the planned transportation system do not exceed the motor vehicle emissions budget established in the SIP. The budget provides the upper limits for emissions in specific years that serve as milestones intended to bring the area into attainment of the air quality standards. If the transportation plan or TIP cannot meet the motor vehicle emissions budget, then changes may need to be made to the transportation plan or TIP, or the SIP. Otherwise, if conformity is not determined according to the timeframes established in the regulations, a conformity "lapse" will occur. When conformity lapses, only Federal projects that are exempt from transportation conformity (e.g. safety projects), TCMs in an approved SIP, or project phases that have already received funding commitments by FHWA or FTA may proceed.

Transportation conformity can have a significant impact on the transportation planning process. Transportation officials must be involved in the air quality planning process to ensure that emissions inventories, emissions budgets, and TCMs are appropriate and consistent with the transportation vision of a region. If transportation conformity can not be determined, projects and programs may be delayed.Transportation conformity can have a significant impact on the transportation planning process. Transportation officials must be involved in the air quality planning process to ensure that emissions inventories, emissions budgets, and TCMs are appropriate and consistent with the transportation vision of a region. If transportation conformity can not be determined, projects and programs may be delayed.

Updated: 07/06/2011
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