Construction can be faster if you accept the disruption of a total closure of the artery and potentially many cross streets.
That level of disruption is generally not tolerated here. So you get very inefficient construction schedules, where much of the time is spent in setting up work areas for a short closure, and tearing down work areas to reopen roadways.
I get that but in this case, there's at grade streets already there. Medford street heading south and the street with the Mercedes Dealership (also Medford?) heading north.
It seems almost straight forward to lower the viaduct while keeping the side streets open. Washington st was fully closed for a year last year and everyone survived.
I live near by and I'd definitely take one year of serious mess over four (likely more) of less mess.
I find looking at closed roads with no construction happening very frustrating. So much so, I'll likely move if this goes ahead.
In a weird way, I'm not sure we need all that traffic at grade and It's probably easier now to cross under the overpass if your on foot or bike than it will be when MassDOT have shoehorned in a ton of filter lanes and then neglect to maintain it.
look at the road that separates east somerville from Fosse park, no thanks!