The Charles River Bridge, referred to by the MBTA as Draw One, is a pair of railroad single-leaf, through-truss, rolling bascule bridges across the Charles River in Boston, Massachusetts that connects North Station to MBTA Commuter Rail lines serving areas to the north.

Although rail bridges across the Charles River near the present location of North Station have existed since the Boston and Lowell Railroad opened in 1835, the current bridges date from 1931, when the navigable channel of the Charles River was shifted 300 feet to the north of its former route to allow the platforms at North Station to be extended northwards.

The unfinished sixth platform at North Station will be completed to serve long out-of-service tracks 11 and 12, the Fitchburg mainline will be slightly relocated to provide more layover space near the maintenance facility, and FX interlocking will be reconfigured.

[3] In September 2024, the MBTA was awarded a $472 million federal grant for the bridge replacement.

[7] The draft environmental assessment was released in December 2024, with bridge construction expected to last from 2026 to 2034.