O'Neill Tunnel

The Thomas P. "Tip" O'Neill Jr. Tunnel is a highway tunnel built as part of the Big Dig in Boston, Massachusetts. It carries the Central Artery underneath downtown Boston, and is numbered as Interstate 93 , U.S. Route 1 , and Route 3. It roughly follows the route of the old elevated Central Artery, though the northbound entrance, at the corner of Kneeland Street and Atlantic Avenue, is somewhat east of the southbound exit to allow for a reconfigured interchange with the Massachusetts Turnpike. It runs from the Zakim Bunker Hill Bridge at its north portal—barely 165 feet east of the TD Garden sports facility's eastern corner—to Boston's Chinatown at its south portal. The tunnel is named for Tip O'Neill, former Speaker of the United States House of Representatives.

Planning for the tunnel began in the mid-1980s, when it was determined that a replacement for the Central Artery was needed. Originally built for 75,000 vehicles a day, the expressway was carrying 200,000 vehicles a day by the early 1990s. It was even projected that, by 2010, there would be 16-hour daily traffic jams that would cost the local economy $500 million annually. Furthermore, the North End was cut off from the rest of the city, which hampered economic growth.

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