The air quality implications of urban road user charging

The impact of five different road user charge schemes on air quality in Leeds was assessed through application of traffic assignment, pollutant emission and atmospheric dispersion models. Modelled scenarios were assessed with reference to road network performance parameters, exceedence of air quality standards, greenhouse gas emission and spatial redistribution of pollution. These were then compared with scenarios representing do-nothing, network development, and greater use of clean fuel vehicles. A modest distance charge is most beneficial overall, although results are sensitive to prior air quality and non-vehicle emissions.