Economy of London project is construction of 42 km (26 mi) of new tunnels connecting stations in central London including a branch to Canary Wharf in east London. It is Europe's biggest construction project with a £15 billion projected cost. An additional line, Crossrail 2, has been proposed. London is served by six international airports which are the world's busiest city airport system by passenger traffic. These are Heathrow, Gatwick, Stansted, Luton, London City, and Southend. There are a number of proposals for expanding airport capacity for London including expansion of London Heathrow Airport and expansion of Gatwick Airport. The principal argument in
London Stansted Airport Stansted's runway is also used by private companies such as the Harrods Aviation, Titan Airways and XJet terminals which are private ground handlers who are able to handle private flights, charter flights and state visits. STN also has a transit inside which helps people to travel to their designated gates and terminals. Originally owned and operated by BAA, since February 2013 the airport has been in the hands of Manchester Airports Group (MAG) following a March 2009 ruling by the Competition Commission. London Stansted Airport has one main passenger terminal, near the village of Stansted Mountfitchet. There are three passenger