The paper introduces a simple framework for analyzing the environmental effects of local transportation policies, and it reviews some evidence. In several cases, subsidies for local public transportation have led to substantial reductions in road transportation and have thereby reduced externalities. Some but not all estimates suggest positive overall welfare effects of such policies. In the rare cases where road pricing has been applied, it has helped to reduce automobile transportation, and it has led to environmental improvements. The experience with specific driving restrictions like “days without cars” and “low emission zones” has been mixed. Local transportation policy can have a useful role to play as a complement to national policy instruments, but neither efficiency nor effectiveness can be taken for granted.