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 City Airport Airport DLR station opened on a branch of the Docklands Light Railway, providing rail access to the airport for the first time, and providing fast rail links to Canary Wharf and the City of London. By 2006, more than 2.3 million passengers used London City Airport. In October 2006 the airport was purchased from Dermot Desmond by a consortium comprising insurer AIG Financial Products Corp. and Global Infrastructure Partners (GIP). In the final quarter of 2008 GIP increased its stake in the airport to 75%, the remaining 25% belonging to Highstar Capital. London City Airport was granted planning permission to