The great weight that the car has as a means of mobility in large cities generates significant negative externalities both in terms of pollution and congestion. The goal of this paper is to examine the effectiveness of low emission zones (LEZs) and to compare it with the existing results in literature on the effectiveness of urban tolls. First, we build up a theoretical model that departs from De Borger and Proost (2012), who study the effects of urban tolls on congestion, by incorporating pollution into the analysis and LEZs as an alternative (quantity-based) policy measure. Then we perform an econometric analysis taking advantage of a unique and extremely original panel of large European urban areas over the period 2008–2016, using data on congestion from TomTom and data on pollution (PM2.5) from environmental sciences. We conclude that LEZs can curb pollution. They are particularly effective in highly polluted cities, when they are applied to a wide area of the city, and/or when they are stringent in the type of restricted vehicles. Instead, LEZs are ineffective in mitigating congestion. This is a very relevant result, given the growing importance of LEZs in Europe.

在大城市中，汽车作为一种交通工具的巨大重量在污染和拥堵方面产生了显着的负外部性。本文的目的是检验低排放区 (LEZ) 的有效性，并将其与有关城市通行费有效性的文献中的现有结果进行比较。首先，我们建立了一个与 De Borger 和 Proost (2012) 不同的理论模型，他们研究了城市通行费对拥堵的影响，将污染纳入分析，并将低排放区作为替代（基于数量的）政策措施。然后，我们利用 2008 年至 2016 年期间欧洲大型城市地区的独特且极其原始的面板，使用 TomTom 的拥堵数据和环境科学的污染 (PM2.5) 数据进行计量经济学分析。我们得出结论，低排放区可以抑制污染。当它们应用于城市的广阔区域和/或当它们对限制车辆的类型很严格时，它们在高度污染的城市中特别有效。相反，低排放区在缓解拥堵方面无效。鉴于低排放区在欧洲的重要性日益增加，这是一个非常相关的结果。