Delaware is centrally situated in the Northeast megalopolis region of cities along I-95. Therefore, Delaware commercial airline passengers most frequently use Philadelphia International Airport (PHL), Baltimore-Washington International Thurgood Marshall Airport (BWI) and Washington Dulles International Airport (IAD) for domestic and international transit. Residents of Sussex County will also use Wicomico Regional Airport (SBY), as it is located less than from the Delaware border. Atlantic City International Airport (ACY), Newark Liberty International Airport (EWR), and Ronald Reagan Washington National Airport (DCA) are also within a radius of New Castle County.