Construction began in 1923, but New York City Mayor John Hylan, a former BMT employee, canceled the project, and the tunnel only went 150 feet (45m) into The Narrows before it was halted. The tunnel lies dormant under Owl's Head Park in Bay Ridge, Brooklyn. Later proposals to complete the tunnel, including the 1939 plans for the ambitious IND Second System, were never funded.
Modern proposals for completion of the tunnel have come from New York City Councilman Lewis Fidler who has proposed a one-third of one percent tax for the tri-state region to pay for the construction. The tunnel is one of many projects that could compete for $3 billion of federal funds that were to have been allocated to the ARC tunnel, which was canceled in October 2010. State Senator Diane Savino, whose district includes parts of Staten Island and Brooklyn, supports such a plan; "The MTA should complete a 1912 plan that would have rail and freight access from the terminus of Victory Boulevard to Brooklyn, along 67th Street, then utilize the R train along Fourth Avenue." An alternative plan would have a tunnel built south of the Bay Ridge – 95th Street station. The plan's projected cost would be $3 billion, "the same as a proposed extension of the 7 line under the Hudson River." Supporters argue that a rail tunnel would improve quality of life for Staten Islanders, reduce traffic, and increase the attractiveness of the borough for investment.
Note that this is a list of New York City Subway lines, which are the physical infrastructure over which services operate.
Lines with colors next to them are trunk lines; trunk lines determine the color of New York City Subway service bullets, except for shuttles, which are dark gray.