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
Groton–New London Airport the onsite fixed-based operator. Columbia Air Services (since 1983) and Lanmar Aviation (since 2003) have been the two fixed-base operators serving the airport. In 2012, faced with declining demand for services, the two proposed merging their Groton operations as a joint venture called Mystic Jet Center. In January 2013, the U.S Department of Justice's Antitrust Division announced that it would not interfere with the merger, citing sufficient competition from nearby airports. Groton–New London Airport Groton–New London Airport is a state owned, public use airport located three nautical miles (6 km) southeast of the central business district of Groton, a town