Route 128 is the loop highway running around Boston.

I do know that much of Boston had no choice but to take a day off on Friday

Much of Boston is not the same as "a large portion of New England." New England is ~14 million people. The affected areas covered about 600K people.

may have cost hundreds of millions, perhaps billions of dollars in economic losses.

Your own link doesn't support "billions of dollars in economic losses." In any event, extraordinary events require an extraordinary response. In any event, I can't see how having those streets packed with cars and pedestrian traffic (as happens on a normal Friday) would have done anything but hinder the manhunt.