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Traffic Detours of Monsignor O’Brien Highway Outbound in Cambridge This Weekend, August 29 and 30

Posted on August 28, 2020

Placement of large steel beams at Lechmere Viaduct continues.

Outbound detour of Monsignor O’Brien Highway to begin at 5 AM on Saturday morning through Sunday evening.


The MBTA announced today it will continue crane lifts this weekend at the new Lechmere Viaduct under construction between the Gilmore Bridge and Lechmere Station along Monsignor O’Brien Highway. The operation necessitates the closing of the outbound lanes on Monsignor O’Brien Highway between the Gilmore Bridge and Lechmere Station.

The activity is in support of the Green Line Extension (GLX) project. Crane equipment setup and traffic detours will be in place by 5 AM Saturday morning, August 29. The placement of large steel beams will support the deck of the new viaduct section. Crane lifts are scheduled from 7 AM to 10 PM on Saturday and from 7 AM to 7 PM on Sunday.

Traffic detours for motor vehicles, pedestrians, and bicyclists traveling outbound or northwest along Monsignor O’Brien Highway will be in place throughout the weekend. The GLX project will extend Green Line service from the new Lechmere Station along 2 new branches to Union Square in Somerville and to College Avenue/Tufts University in Medford.

Anticipated noise levels during the overnight periods are expected to be light to moderate. 

Weekend Detour Routes: August 29 and 30

On Saturday morning, Monsignor O’Brien Highway will be closed to outbound traffic from the Gilmore Bridge/Charlestown Avenue to East Street in East Cambridge. 

During this phase, all motor vehicles traveling outbound (northwest) on Monsignor O’Brien Highway will be directed to bear left on Edwin H. Land Boulevard, make a right on Binney Street, turn right on Third Street, and proceed to Monsignor O’Brien Highway.

Motor vehicles, trucks, and bicyclists traveling inbound (southwest) on Monsignor O’Brien Highway will not be affected.  Pedestrians traveling inbound along Monsignor O’Brien Highway will be directed to use the south sidewalk.

Trucks traveling outbound (northwest) will be directed to make a right at the Gilmore Bridge, turn left on Rutherford Avenue, turn right on Washington Street at the Sullivan Square Rotary, and proceed to McGrath Highway.

Pedestrians traveling outbound (northwest) on Monsignor O’Brien Highway will be directed to cross over to the south sidewalk and continue on Monsignor O’Brien Highway, bear left on Cambridge Street, turn right on Second Street, turn right on Gore Street, and proceed to Monsignor O’Brien Highway.

Bicycles traveling outbound (northwest) on Monsignor O’Brien Highway will be directed to turn left on Edwin H. Land Boulevard, turn right on Rogers Street, turn right on First Street, turn left on Cambridge Street, turn right on Third Street, and proceed to Monsignor O’Brien Highway.

The MBTA appreciates the patience and understanding of motorists and others affected by construction as the GLX Project Team continues to make strides in delivering GLX to the region on schedule. The MBTA also thanks its city partners, municipal leaders, and stakeholder groups for their continued collaboration and support of GLX.

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