Leonard P. Zakim Bunker Hill Bridge - Boston, Mass.
A signature project of Boston's multi-billion dollar Central Artery/Tunnel, the Leonard P. Zakim Bunker Hill Bridge spanning the Charles River was completed in 2002 and opened to traffic in March 2003.
The $100 million, 10-lane asymmetrical cable-stayed bridge has been recognized as a monumental achievement in American bridge engineering and construction. It is the first asymmetrical cable-stayed bridge in the United States and the widest cable-stayed bridge in the world. Kiewit led the joint venture that began construction on the 183-foot-wide structure in September 1997.
The bridge's main elements are the two inverted Y-shaped hollow-core concrete towers located on opposite sides of the Charles River. Crews used a cast-in-place construction method for the towers as a part of a value-engineering proposal. The south tower reaches a height of 295 feet, while the north tower extends 323 feet high. These structures support the 745-foot steel center span. Eight lanes of I-93 traffic pass between the legs of the towers and two lanes of local traffic are cantilevered off to the bridge's east side.