United Airlines, the Metropolitan Washington Airports Authority and the Department of Transportation have unveiled a more than $20 billion redevelopment of Washington Dulles International Airport. The decade-long programme replaces the ageing C/D concourse, adds or modernises multiple concourses, upgrades the Main Terminal, expands security, ticketing, concessions and lounge capacity, and extends AeroTrain and underground passenger links while phasing out mobile lounges. United also plans one of its largest Polaris Lounges and a larger club footprint. Concourse E, with 14 United gates, is already under way and due later this year, while the wider buildout is set to keep the airport operating through phased construction.