Road user charging is used as an 'umbrella' term to describe a wide range of applications of pricing roads and infrastructure. Road user charging includes a number of charging measures that governments and other road owners use to: i) finance new or maintain existing road infrastructure ii) manage traffic (e.g. reduce congestion) iii) minimise environmental impacts of transport iv) internalise the external costs of road transport caused, e.g., by pollution and noise emissions. Historically, the common approach to charging for road use is some form of general taxation rather than differentiated road user charging. Road user charging has long been proposed as an efficient and equitable method to pay for road use and to fund road infrastructure projects. However, there is an important distinction between charging for revenue generation purposes as opposed to pricing roads to provide congestion relief. The two basic objectives, revenue generation and congestion management, differ in several ways, as shown in the following table.