Caption: A southbound train of 01800s crosses the Longfellow Bridge before entering Charles/MGH Station. Until 1952 a track ran down the left-hand lane on the road that you can see before joining with the Red Line on the other side of the bridge. This was to allow cars from the Blue Line access to the Red Line's Eliot Square Shops near Harvard. The track (and the Blue Line itself) was originally a streetcar line providing service between Cambridge and East Boston. (December 22, 2006)
