The Congressional Subway
in Washington, D.C
is a short-haul electric train system that consists of three short lines (of about 200, 300 and 450 yards). It connects the U.S. Capitol
building to three Congressional office buildings - the Russell Senate Office Building, the New (Dirksen) Senate Office Building, and the Rayburn (Hart) House Office Building. It is open to Congressmembers and their visitors, free of charge. The system has human operators, primarily in order to provide patronage jobs and so that the operators can enforce the "members only" or "senators only" rules that limit nonmembers to certain sections of the cars or that prohibit them altogether during roll call votes.
The system was originally built in 1909 to link the Russell SOB to the Capitol. The Dirksen SOB was added to the system in 1954 and the Rayburn HOB in 1965. The system first ran on March 7, 1909, and was last updated in 1994.
See also Washington Metro.