The Grand Junction Railroad Bridge is a steel plate girder bridge carrying the Grand Junction Railroad over the Charles River in Boston, connecting the Boston University campus to Cambridgeport.

In September 2009, the Commonwealth of Massachusetts finalized[2] an agreement to purchase several CSX rail lines in eastern Massachusetts, including the Grand Junction tracks from the Beacon Park Yard in Allston, through Cambridge.

[4] On November 21, 2012, the Grand Junction Railroad Bridge was closed to all rail traffic due to its poor condition.

This was a change from a restriction put in place days earlier, on November 16, which barred freight trains from crossing, as well as restricting MBTA and Amtrak equipment moves to 5 miles per hour (8 km/h).

While emergency repairs were under way, trains moving between the north and south sides of Boston had to be routed via Pan Am Railways trackage between Ayer, Massachusetts and Worcester, Massachusetts (a detour over 100 miles [160 km] in length).