Every subway station is equipped with an elevator and most with escalators. Layout of Washington, D.C. Layout of Washington, D.C., conceived by Pierre Charles L'Enfant in 1791 and completed by Andrew Ellicott, remains much as it was originally designed. The basic concept is quite simple. Starting from the Capitol, streets running north and south are numbered in ascending order, and streets running east and west are lettered in ascending order. Numbered streets are regular but some lettered streets have omissions.
Broad avenues bear the names of states and run diagonally.