Were traffic restrictions in Madrid effective at reducing NO2 levels?

In this paper we assess the effectiveness of the introduction of Madrid Central, a low-emission zone (LEZ), to improve air quality in the centre of Madrid. We take advantage of this policy change to identify the effect of the application of an LEZ on NO2 concentrations. Our findings provide evidence that the introduction of Madrid LEZ has had a positive impact on reducing NO2 emissions, as measured by Plaza del Carmen's monitoring station. Furthermore, monitoring stations located near to Madrid LEZ also exhibit significant, though smaller, reductions in NO2 levels. These results suggest that there was a positive spillover effect and that pollution was not transferred from the city centre to other nearby areas. Instead, it seems that citizens in Madrid actually changed their transportation habits.

Automated summary

The implementation of Madrid Central, a low-emission zone, has effectively reduced NO2 emissions in the city center, as found through monitoring at Plaza del Carmen. Monitoring stations near the LEZ also saw significant reductions in NO2 levels, indicating a positive spillover effect. This suggests that the introduction of the LEZ led to changes in transportation habits among Madrid citizens rather than transferring pollution to other nearby areas.