The Subway of Boston

The subway system has three rapid transit lines—the Red, Orange and Blue Lines, and two light rail lines—the Green Line and the Ashmont--Mattapan High Speed Line (designated as part of the Red Line). The system operates according to a spoke-hub distribution paradigm, with the lines running between central Boston and its environs. All four colored lines meet downtown at a square configuration, and the Orange and Green Lines (which run parallel) meet directly at two stations. The Red Line has two branches in