Air Quality Conformity

Transportation planning in the region is heavily influenced by air quality planning, which like financial constraint, is a federal requirement. Once the financially constrained element of the long-range transportation plan (LRTP), currently called Visualize 2045, is drafted, it is tested to ensure that, the plan's projects 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 LRTP 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 constrained element "conforms" to air quality improvement goals. If the TPB encounters difficulty in meeting conformity - or expects 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. This information is documented in an Air Quality Conformity Determination report. 

Visualize 2050 National Capital Region Transportation Plan
2025 Air Quality Conformity Analysis Update

Visualize 2050, the National Capital Region Transportation Plan, is the update to Visualize 2045. In 2025, TPB staff completed an Air Qualiy Conformity Analysis of the projects in the draft Visualize 2050 plan. To learn more, view the Visualize 2050 Air Quality Conformity FAQs. 

Public Comment Opportunity

The draft Air Quality Conformity Analysis Report, along with the Visualize 2050 draft plan, and draft FY 2026-2029 Transportation Improvement Program, is open for public comment October 23-November 21, 2025. Visit visualize2050.org to view the report and for information on how to comment.