This is along Mooney St (right?) on the Blanchard/Concord Ave side of the tracks. This is a slightly better place for development because the grid is a little more redundant along Concord and Blanchard.
Let 's be clear, though, this is AN overpass, it is
not THE overpass that Cambridge has long sought.
The long sought overpass is shown in a concept below. It goes much closer to the Red Line (within about 300ft +/-
from here) and the current rail maintenance building (and near where you'd want RUR to have a station:
Meanwhile, This developer 1000' west (out on Mooney street) proposes an amenity that would nicely serve people commuting by Red Line, but ONLY IF their home/connection in the core, as it is about as straight a shot toward Alewife as you can affordably build here.
Oh God no, not more development around here! They need to fix Alewife Brook Parkway and add another outlet onto Route 2 West!!! Forcing cars to turn around at the rotary in order to get back to the highway is BRUTAL. Route 2 West is always totally clear too, at least up through the 95 interchange. It's just that GETTING ONTO Route 2 is a nightmare!!!
No amount of new capacity are going to "fix" ABP precisely because (as you point out) Rt 2 has so very much slack capacity...Rt2 has more than enough to deliver enough new users to Alewife to fully (re)congest any new ABP capacity you could imagine.
(It would actually work the other way: if you want traffic in Alewife to ease up, imagine how many fewer people would drive if Rt 2 were 1 lane in each direction)
Put another way: the main reason that ABP is so bad is because Rt2 is so empty--making the crushing miseries of APB "worth it" for the pleasure of going to/from Rt 2