Regional Transportation Planning Through Intergovernmental Collective Action: Does Planning Conformity With Federal Regulations Improve Regional Air Quality?

This study examines whether metropolitan planning organizations’ (MPOs) planning conformity, which is the degree to which regional transportation planning language aligns with federal air-quality requirements, is associated with regional attainment of the National Ambient Air Quality Standards (NAAQS). MPOs operate at the intersection of transportation and environmental regulation, coordinating across multiple governments to address cross-jurisdictional air pollution. We measure planning conformity using a content analysis that combines the Institutional Grammar framework with automated text analysis (natural language processing) to compare MPO transportation plans with relevant federal regulatory language. Using a sample of 84 MPOs in U.S. Environmental Protection Agency Regions 1–3, we estimate the relationship between planning conformity and 2023 county-level attainment status. Results indicate that higher planning conformity is associated with higher odds of NAAQS attainment, net of institutional, infrastructure, and state-level controls.