Commonwealth Avenue bridge replacement project to begin Thursday

Bridge beams and construction materials are being staged and assembled at the Beacon Park Yard in Allston for the Commonwealth Avenue Bridge Project.
Bridge beams and construction materials are being staged and assembled at the Beacon Park Yard in Allston for the Commonwealth Avenue Bridge Project.David L. Ryan/Globe Staff/File 2018/Globe Staff

The replacement of the westbound side of the Commonwealth Avenue Bridge, scheduled to start this week, will upgrade Boston’s transportation infrastructure, but it will bring headaches for some travelers.

The $110 million bridge replacement project began last summer, when the eastbound side was redone. This summer, between July 26 and Aug. 11, the westbound side will be demolished and replaced, causing “significant travel impacts,” the Massachusetts Department of Transportation said in a statement.

The bridge carries Commonwealth Avenue in the Boston University area over the Massachusetts Turnpike and various rail lines.

Starting this Thursday evening, crews will shut down a section of the bridge and the Boston University Bridge, which connects to it and carries traffic across the Charles River into Cambridge.


The MBTA buses that would normally make use of the bridges, like the CT2 and 47 routes, will be detoured, and the B branch of the T’s Green Line will be replaced by shuttle buses at the start of service this Friday. People driving on Interstate 90 in Boston will see lane reductions starting that evening, officials said.

The actual demolition of the westbound side of the bridge will begin this Saturday, July 28, and anyone looking to take the MBTA Framingham/Worcester Commuter rail line or the Amtrak Lake Shore Limited line that weekend or the following will have to seek an alternate route. These two lines will be replaced by bus shuttles during the two weekends of construction, officials said.

After Aug. 11, the major work is expected to be completed, though other more minor work on the bridge will continue until some point in 2019, MassDOT spokesman Patrick Marvin said.

Under conventional construction techniques, the project would take four to five years with more significant lane-takings and service disruptions, officials said.

This summer’s replacement work will involve the use of three cranes, weighing 600 tons each. The cranes will be used to install 45 steel beams, 214 pre-fabricated concrete deck panels, 680 cubic yards of additional concrete, and 520 tons of hot mix asphalt.

The MBTA is encouraging people to use the technology tools that are available to them to help make their travel more manageable during the construction. Among these tools are the mass511.com website and the GoTime travel app. The MBTA is also recommending that people sign up for e-mail notices to receive construction updates and traffic alerts.


Andres Picon can be reached at andres.picon@globe.com. Follow him on Twitter at @andpicon.