Lessons of Boston’s Big Dig by Nicole Gelinas, City Journal Autumn 2007

Although the article notes the "success" of the Big Dig, as measured in travel times, I would have to say the project is a miserable failure in terms of how the benefits were achieved. For a mere fraction of the amount spent, residents could have gotten improved travel times and a new, central green space through improved rapid transit and land-use planning; plus, they would've gotten better air quality and a reduced dependence on foreign oil in the deal.

A financial analyst, Ms. Gelinas notes that the project
team should've accounted for inflation in its initial cost
estimates in order to understand the true lifetime costs of the Big Dig. Likewise, Ms. Gelinas should account for how much the world has changed since that initial cost
estimate was made and realize that the old paradigm of
providing endless highway capacity for droves of single-
occupant vehicles has come up against an emerging set of
environmental limits, not the least of which includes
climate change and global-oil depletion.

Nicole Gelinas responds:

The reader implies that the Big Dig was part of the "old paradigm of providing endless highway capacity for droves of single-occupant vehicles." In fact, the Big Dig, for the most part, was about improving existing highway capacity, rather than adding new highway capacity. It has reduced pollution by reducing travel times on trips that would have been made by highway, anyway, rather than create new highways.

It is likely, further, that "improved rapid transit," were it enough to actually replace highway capacity in Boston, would have carried a price tag within the multiple billions of dollars, as well, rivaling the Big Dig in terms of cost.