The air quality impact of cordon and distance based road user charging: An empirical study of Leeds, UK

Traffic assignment, pollutant emission and dispersion models were applied to a major UK city so as to assess the air quality impacts of five road pricing schemes. Schemes were evaluated with reference to: exceedence of air quality standards for six pollutants; greenhouse gas emission; redistribution of pollution, an environmental justice concern; and road network performance as traffic speed and trip distance. Results were compared to alternatives of do nothing, network development and clean fuel promotion. The air quality benefits of a modest distance-based charge are highlighted. However, whilst road pricing shows potential as an air quality management tool, its value and suitability are strongly sensitive to prior air quality and emission source apportionment in the application city.