Ongoing research to provide a sound basis for designing practical urban road pricing systems that produce maximum benefits is reported. In particular, the concern is with the levels of charge and the number and location of charging points in the road network. Practical (judgmental) approaches to cordon location based on evidence from proposed and implemented road pricing systems around the world are reviewed, and the results of work to test a mathematical approach for optimizing charges and charge locations on a prespecified subset of links in a very simple, illustrative network are described. The application of these principles to a real network is then considered. It is shown that a considerable gap currently exists between the state of the art in network optimization approaches and the requirements of policy makers and that, as a result, judgmental cordon designs are often substantially suboptimal. In conclusion, possible ways forward for identifying the most appropriate number and location of charging points are discussed.
Abstract