MBTA to shut portion of Green Line D branch in June for work May 31, 2021 FacebookTwitterEmail BOSTON (AP) — The Massachusetts Bay Transportation Authority is fast-tracking work on the Green Line’s D branch in June that will require a full closure of the track for a total of 18 days, officials said. The MBTA’s Green Line D Track and Signal Replacement Project includes replacing 25,000 feet of track and 6.5 miles of signals — some elements of which date to the 1950s — from Riverside to Beaconsfield stations, the T said. Beginning after the end of normal service on Friday, crews will work 24 hours a day for a total of 18 days to perform the work.