The potential of road pricing schemes to reduce carbon emissions

Road pricing is a transport measure mainly conceived to fund road management, to regulate the demand for traffic and to reduce the number of private vehicles circulating in urban areas. It can also grant benefits in terms of environmental externalities including the reduction of CO2 emissions, which has recently become one of the most important elements defining the sustainability of a transport system. However, the carbon potential granted by road charging is rarely assessed economically, thus confirming a sort of secondary role attributed to CO2 in urban premises. This paper provides an accurate analysis of the relationship between the different forms of road pricing (distance-based, congestion-based and pay-as-you-drive) and their effective role in terms of carbon reduction, which in some contexts is significant, accounting for an overall percentage higher than 10%. Furthermore, practical suggestions to policy makers in terms of implementation of the measure are discussed, highlighting the precautions necessary to include a fair carbon evaluation into an overall effective analysis.