Weekly Roundup - phasing facts Recap and analysis of the week in state government BOSTON - The historic Hoosac Tunnel, running through the mountains between North Adams and Florida, is four-and-three-quarters miles long. The Big Dig's Tip O'Neill Tunnel goes for a mile and a half under downtown Boston. And the tunnel we unknowingly descended into sometime last winter when the novel coronavirus first arrived in Massachusetts? That one's measured not in miles, but in months, and we still have a ways to go before coming out the other side, or even before knowing exactly how much of the trek remains.