How do low emission zones impact air quality and mobility? Evidence from Brussels.

Abstract

Low emission zones have become popular for dealing with air pollution in urban centers and mitigating its detrimental effects. This research examines the impact of this policy on the city of Brussels for which literature is scarce, on both air pollution and mobility. Through a differences-in-differences method, the effect of the LEZ can be isolated. Studying mobility through the vehicle fleet indicates that the policy is effective in reducing the share of diesel vehicles (-2.9%) but does not induce substantial changes towards less polluting vehicles. The policy influences however more individuals living on the outskirts of Brussels to switch to greener vehicles than the ones living inside. Furthermore, findings indicate that the policy reduces nitrogen dioxide levels by 2.1% inside the zone and by approximately 5% in its surroundings. It however leads to an increase in ozone levels of 5.5% in the concerned area. The study of spillover effects leads to the conclusion that individuals do not bypass the zone to avoid it. Finally, it appears that the wealthiest individuals benefit the most from the policy in terms of air pollution. Overall, these results suggest that additional policies to promote the greening of the vehicle fleet could be beneficial and that strategies to address rising ozone levels should be explored, as well as policies to address the potential inequality aspect of the LEZ.