Final stretch of Green Line Extension will open Dec. 12

One final delay of a couple of weeks looms, and then the long-awaited second and final Green Line Extension branch will open to riders on Dec. 12, MBTA General Manager Steve Poftak announced Thursday.

All five new stations along the Medford Branch will come online at the start of service Dec. 12, Poftak said, bringing rapid transit service to densely populated areas near Tufts University, eastern Somerville and the Winter Hill neighborhood.

MBTA officials have already delayed the Medford Branch's launch several times, most recently this summer, when they targeted late November for opening day.

"Our original hope was to be opening toward the end of November. We had some additional work we wanted to get done. We also wanted to be sure we were doing everything we needed to do, not only on the Medford Branch but across our system," Poftak said at an MBTA board meeting. "We're taking a few extra days, but we will open at the beginning of service on Dec. 12."

The launch will cap off the most significant MBTA expansion in decades and complete a project that appeared nearly dead at varying points in its years-long history.

The Green Line Extension's smaller first leg, which opened a newly constructed Lechmere Station and a brand-new Union Square stop, began shuttling passengers in March.