The Highways Agency has forecast that traffic is anticipated to increase by 40% by 2025 and that this growth will create increasing congestion on UK roads. As the Government has said “Doing nothing is not an option”. Charging drivers directly for using the roads is one mechanism that could help address this problem. Road pricing (also known as road user charging, road tolling, congestion charging, electronic fee collection) requires the use of electronic systems of various kinds (microwave transponders, number-plate recognition, GPS plus mobile radio) to identify vehicles travelling on particular roads and to charge them appropriately.