The impact of cordon design on the performance of road pricing schemes

Road pricing schemes are principally based on cordon-based pricing. Earlier studies have demonstrated that the performance of cordon schemes is critically dependent on cordon location. However, surveys of those designing such schemes indicate that they are opting for the simplest designs, in the interest of acceptability, and may well be overlooking designs which achieve greater economic benefit. A set of analytical procedures has been developed for identifying the locations for imposing charges and the charges at those points which are optimal in terms of economic efficiency. These are demonstrated on a simplified network of Cambridge. Tests on a larger network confirm that performance is very sensitive to cordon location. However, they also show that charging points selected by even a simple analytical procedure can achieve economic benefits around 50% higher than predefined cordons, and that relaxing the requirement to have uniform charges at all charging points can produce further substantial increases in economic benefits.