Demand on the South West Main Line is dominated by the London commuter market, with around 85,000 people alighting at either Waterloo or Vauxhall every morning. Some routes experience serious overcrowding. Passenger kilometers on the route in the morning peak are forecast to grow by 14% over the 10-year period of this RUS. There is no easy way to deal with this demand: the analysis so far suggests that a significant volume of investment will be required to enhance the capacity and capability of the SWML railway system.

The South West Main Line (SWML) was chosen to be the pilot Network Rail led RUS for the following reasons:

• To inform the development of the specification for the South Western franchise.
• Overcrowding and growth issues on certain sections of the line need to be addressed.
• The future of the Waterloo International Terminal after the expected withdrawal of Eurostar services in 2007 is being examined, and capacity at London Waterloo is critical to any future requirements for the SWML.
• To inform the development of the Department for Transport’s High Level Output Specification for an area where there is significant congestion on parts of the route combined with substantial potential growth.