As much as this appeals to me, it doesn't seem feasible: the problem is that this road ends at the Harvard Bridge (so called because it isn't near Harvard, because Boston), which crosses the river into Boston. Close this off, and traffic on the two adjacent river crossings, the Longfellow and BU Bridges, goes from "terrible" to "you should have walked".

Aha! you say, there is a perfectly good subway right there! Why don't people take that? Because the MBTA, our transit agency, is a notorious disaster. I won't load you down with examples here, but you can google e.g. "MBTA dumpster fire" or "what is wrong with the MBTA" and soon you'll know all you need to know.

I am a little bit hopeful that Philip Eng, the former head of LIRR and new GM of the MBTA, will be able to turn it around. He really seems to mean business, and he's an actual engineer with experience running a railroad. The old GM, Steve Poftak, was mainly qualified by having an MBA, having the right ideological positions, and knowing the old governor. I don't think anyone is going to miss him.