Northeast megalopolis includes people.
The Northeast megalopolis ( also Boston -- Washington Corridor or Bos-Wash Corridor ) is the most heavily urbanized region of the United States , running primarily northeast to southwest from the northern suburbs of Boston , Massachusetts , to the southern suburbs of Washington , D.C. , in Northern Virginia . America 2050 projections expect the area to grow to 58.1 million people by 2025 . An urban area is a human settlement with high population density and infrastructure of built environment .