Boston-area streetcar lines remaining in 1940 (in green), plotted against a map of the BERy's subway and elevated lines (in purple). The shade of green for each line denotes how long the line lasted after this; the lightest-green lines were abandoned in 1945 or earlier, the second-lightest lines were abandoned from 1946 to 1950, the second-darkest lines were abandoned from 1951 to 1969, and the darkest-green lines still existed in 1969.
As with many large cities, a large number of Boston-area streetcar lines once existed, and many continued operating into the 1950s. However, only a few now remain, namely the four branches of the Green Line and the Ashmont–Mattapan High-Speed Line, with only one (the Green Line E branch) running regular service on an undivided street.
