Air Quality Planning in The Washington Region

Transportation planing in the Washington region is heavily influenced by air quality planning. Like financial constraint, air quality conformity is a federal requirement. Once the CLRP is drafted, it is tested to ensure that the projects in the plan, when considered collectively, contribute to the air quality improvement goals embodied in the Clean Air Act Amendments of 1990. A series of tests are performed with computer models that predict how much air pollution will be generated over the next 25 years by facilities in the plan, and how much the air will be improved by cleaner gasoline standards and many other factors.

If the CLRP is found by the TPB to meet regional air quality goals, federal agencies certify that the plan is "in conformity." In other words, the TPB ensures that the CLRP "conforms" to air quality improvement goals. This is documented in the Air Quality Conformity Determination of the 2007 Constrained Long-Range Plan and the FY 2008-2013 Transportation Improvement Program for the Washington Metropolitan Region.

A conformity determination lasts three years - the life of the CLRP itself. If the TPB encounters difficulty in meeting conformity - or extpects to - it may choose to adopt Transportation Emission Reduction Measures (TERMs), such as ridesharing and telecommuting programs, improved transit and bicycling facilities, clean fuel vehicle programs or other possible actions.

Program Contacts

Mike Clifford - (202) 962-3312
Jane Posey - (202) 962-3331