core of the subway system is shown on the back cover, with an inset map of the entire system being shown on the map itself. Spelling corrections have been made and changes to touristic sites noted. Ground Zero is now shown as the Sep 11 Memorial. The regional map on the other side of the paper is brand new. The Northeast Corridor from Boston to Washington is difficult to portray sensibly, since it runs from northeast to southwest whereas a sheet of paper is rectangle, so the coverage extends considerably west of the rail line forming the 'Corridor', but that's just an added bonus. This is an excellent map for day trips of regional travel, particularly for those driving or going by train to Washington. An inset map of central Washington is included, covering the Mall area. Scale 1:800.000/Manhattan 1:12.500. 4th edition 2018.