The Boston Big Dig was a massive infrastructure project that took place in Boston, Massachusetts from 1991 to 2007. It involved the construction of a network of underground highways, tunnels, and bridges to replace the aging elevated Central Artery highway. The project was the largest and most complex highway project ever undertaken
The Big Dig was a megaproject in Boston that rerouted the elevated Central Artery of Interstate 93 into the O'Neill Tunnel and built the Ted Williams Tunnel to extend Interstate 90 to Logan International Airport. Those two projects were the origin of the official name, the Central Artery/Tunnel Project. The megaproject constructed the Zakim Bunker Hill Bridge over the Charles River, created the Rose Kennedy Greenway in the space vacated by the previous elevated roadway and funded more than a dozen projects to improve the region's public transportation system. Planning began in 1982 and construction was carried out between 1991 and 2006. The project concluded in December 2007.