Dissuasive effect of low emission zones on traffic: the case of Madrid Central

Abstract

Ambitious goals to combat pollution should be supported in policies that discourage the use of private cars, notably old and more polluting vehicles. Price signals, such as a congestion tax, and traffic restrictions, such as low-emission zones (LEZ), are widely used tools among European cities to limit car use. In this paper, we look at the dissuasive effect of the implementation of the Madrid Central LEZ and analyze how traffic intensity has been affected in both the restricted area and in other zones of the city. Although the ultimate policy goal of LEZ is to reduce pollution, the instrument considered is traffic limitations, so it is important to know whether or not traffic intensity has been affected by traffic restrictions. Despite its limited extension and the adoption of long transitional periods, the LEZ of Madrid has been seriously questioned from its inception. The results show that traffic intensity has been reduced in the Madrid Central zone but has unfortunately increased in bordering areas. Previous studies on the effects of Madrid Central have not taken into account this potential substitution effect. The future design of a mobility policy in the metropolitan area of Madrid should address this undesirable outcome.