After 16 years and nearly $15 billion, Boston’s Big Dig underground highway system is scheduled to be officially declared complete on New Year’s Eve.
The Big Dig is the costliest and most complex highway project in U.S. history. It was originally thought it would cost less than $3 billion dollars to build.
The project has been plagued by cost overruns, thousands of water leaks, the use of some substandard materials and a fatal concrete ceiling collapse.
But Big Dig boosters say it’s still an engineering marvel that moved a section of Interstate 93 underground and cut the average driving time through Boston from 20 minutes to less than three.