Thomas P. O'Neill Jr. Tunnel (Central Artery/Tunnel 'Big Dig')

The Thomas P. O'Neill Jr. Tunnel is the downtown section of Interstate 93 constructed as the core of Boston's Central Artery/Tunnel Project (the 'Big Dig'). It runs beneath downtown Boston and carries north–south highway traffic under landmarks including Boston City Hall Plaza. The tunnel replaced the elevated Central Artery and major sections were completed and opened to traffic by 2003. It is officially named for former U.S. House Speaker Thomas P. O'Neill Jr.