392623 04: Workers pour concrete during construction on the Central Artery project July 30, 2001 in Boston, Massachusetts. The Central Artery project, known as the “Big Dig”, will re-route city traffic underground. The project, which is the costliest federally funded project in the history of the United States, with cost overruns totaling in the billions of dollars, is set to open in the autumn of 2002. (Photo by Darren McCollester/Getty Images)