From Metropolitan planning to Transport Management Area: a change of air?

The aim of this study is to investigate policy actions and institutional changes in local governance structures as determinants of air pollutant reductions in US urban areas over the last decade. We adopt regression discontinuity design techniques for the evaluations of pollution reduction policies, exploiting the designation of US Transport Management Areas as a quasi-experimental framework. Results show they provide a governance framework that might facilitate the implementation of policies that reduce traffic congestion and improve air quality.