The Fifth Annual Impacts Monitoring Report , the latest in a series of annual reports describing the impacts of congestion charging in central London, draws on the most recent data for 2006. As with previous reports in this series, it provides a summary and interpretation of the growing body of evidence and insight from across the monitoring program relating to the central London congestion charging scheme. It makes comparisons with conditions before charging started and, where appropriate, with Transport for London’s (TfL’s) expectations for the scheme before it was launched.

This report also considers the impact of important variations to the original scheme, such as the increase in the daily charge implemented in July 2005. Until July 2005, the congestion charge was a £5 daily charge for driving a vehicle on public roads within the congestion charging zone between 7:00 AM and 6:30 PM, Monday to Friday, excluding weekends and public holidays. Since July 2005 the basic daily charge has been £8, with a discount for monthly and annual payments, and for vehicles registered on the TfL "fleet scheme". Motorists can buy a prepaid weekly, monthly, or annual pass and save 15 percent, or buy a daily pass and pay full price. Residents receive a 90 percent discount; however, motorcycles, licensed taxis, vehicles used by disabled people, some alternative fuel vehicles, buses, and emergency vehicles are exempt.

The analysis performed to calculate the cost-benefit ratios quantifies the main identifiable costs and benefits. Previous versions of the monitoring reports used provisional estimates of the costs and benefits of the central London scheme. With continued experience and evaluation, this version of the monitoring report is able to use fully measured benefits and costs for evaluating the initial £5 charge. For evaluating the £8 charge, benefits and costs were produced using comparative estimates with some measured data and some modeled data.

The principal benefits of congestion charging in central London are time and reliability savings to road and bus users that travel within the charging zone. The time savings are based on observed flow and speed data collected before and after charging was introduced. Travel time reliability savings are estimated, but consistent with estimates that have been produced in other places.

The principal on-going costs, calculated using traditional resource-based estimates, are those of operating the congestion charging system and of operating additional bus services to accommodate deterred trips. They include such items as the payments to TfL's contractors, principally the key service providers involved in operating and enforcing the scheme. Another way to consider costs in the analysis is using the Public Accounts approach as defined by the Department of Transport. This approach indicates that the costs should also include the impacts to the public sector, which includes the net effects on public accounts.

RESULTS

• The congestion charging scheme in central London, using the more conservative Public Accounts approach, found benefits exceeding costs by a ratio of 1.5:1 for a £5 charge and 1.7:1 for an £8 charge.
• The more traditional resource-based estimates of benefits and costs produced cost-benefit ratios of 2.0:1 with the £5 charge and 2.5:1 with the £8 charge.