Reducing Air Pollution from Urban Passenger Transport: A Framework for Policy Analysis

Air quality is declining in urban areas, in part because of the rapid motorization of societies world-wide. To combat the problem, various pollution control strategies have been used or proposed for urban passenger transport. This paper develops a simple framework to analyse the impact of these strategies. The paper examines the point of impact of different policy levers and categorizes different instruments in a way that should help policy makers choose between them. The framework explicitly recognizes behavioural incentives, especially the fact that offsetting changes in consumer behaviour can often undermine the original intent of particular policies. The paper concludes that policies aimed at improving transport efficiency often improve air quality at the same time. However, supply side policies to relieve traffic congestion can conflict with the objective of controlling air pollution. It is hence vital that policy makers are aware of the incentives created by different interventions and weigh the impact of these incentives on subsidiary objectives before adoption of particular policies.