Transportation planning in metropolitan communities strives to maximize mobility and accessibility while simultaneously minimizing air pollution. The MPOs are composed of representatives from regional transportation organizations and local governments. The process begins with public participation and input that reflects the values and priorities of the community. A demonstration of conformity is required to receive federal funds and approvals before advancing projects. If the demonstration cannot be made, only certain projects may proceed until it can be.
Conformity brings together transportation and air quality planning.
By contrast, each State air quality agency is responsible for developing a plan to achieve the national air quality standards. Without adequate planning to address both the transportation needs and for attainment of the standards, the conformity process can become unbalanced, making the demonstration of conformity problematic. The CMAQ program, which has sometimes been referred to as the funding arm of the Clean Air Act, has a direct and important relationship with conformity and air quality compliance. It can be an important funding strategy for implementing such measures as CAA-required inspection and maintenance programs or conversions to alternative fuels. One of its greatest benefits has been toward assisting the demonstration of conformity.