As any New Yorkeror visitor to the city knows, the subway system is a labyrinth. This is because it is an amalgamation of three separate systems, two of which incorporated earlier urban railway lines. The current New York subway system was formed in 1940 when the IRT (Interborough Rapid Transit), the BMT (Brooklyn-Manhattan Transit) and the IND (Independent) lines were merged. The IRT lines date to 1904; the BMT lines to 1908 (when it was the BRT, or Brooklyn Rapid Transit); and the IND to 1932. Portions of the IRT and BMT lines originated as elevated train lines, some dating back to 1885. More →