The Route 93 southbound tunnel is the last major transportation part of the $14.6 billion project which promises to transform the city by putting the highway underground. The project was riddled with cost overruns and the Massachusetts Turnpike Authority, which oversees the project, is in the process of considering action after a report last year issued by the Inspector General blamed the project's lead contractors, Bechtel Corp. and Parsons Brinckerhoff, for some of the overruns.

The Turnpike Authority was originally going to have a Boston Pops concert in the tunnel, but after a loud public outcry over the cost of the event, it was canceled. "It is clear that the issues surrounding this celebration are detracting from this important milestone and the efforts of everyone involved with this great engineering feat," says Turnpike Authority chairman Matthew J. Amorello. "We are being responsive to the concerns about using any public funds for this event."

The Route 93 southbound tunnel is the third major portion of the Big Dig to open this year, following the opening of the Massachusetts Turnpike extension in January and Route 93 northbound in March.