The original portion of the Red Line
began operation as the Cambridge Subway in 1912, with a fairly short
route from Park St. downtown to Harvard, across the Charles River.
Fairly early on the line reached Ashmont to the south. Extensions in the 1970s and 1980s lengthened the route
north to Alewife, and added a long second branch
across the Neponset River and through Quincy to the south.
The total length of the Red Line, original Ashmont route and later
Braintree route combined, is a bit over twenty miles -- by far the longest of
the three Boston heavy rail services.
This center city view is at Downtown Crossing. There are three stops along the line under Boston's traditional
downtown, Park St., Downtown Crossing and South Station. Those
wishing to get to the Blue Line for a trip to Logan Airport or
do that only with an intermediate transfer to the Orange Line at this
station, or to the Green Line light rail at Park St. In either
case, the Blue Line is one stop away, to the northeast.