The Washington region contains three major airports: Ronald Reagan Washington National Airport (DCA), Washington Dulles International Airport (IAD), and Thurgood Marshall Baltimore Washington International Airport (BWI). Washington’s airport system has grown in passenger volume in recent years, but the distribution of passengers is uneven.

While the total number of people boarding at the three airports increased 9.4 percent from 2012 to 2016, Dulles’s volume has decreased. Consequently, BWI and National have increased their passenger share at Dulles’s expense. Increasingly, Washington and Baltimore residents are likely to use National or BWI for domestic travel, while Dulles has a larger share of international traffic.