Distant view, looking northeast over the Charles River, with the Longfellow Bridge (1907) in the foreground; The Leonard P. Zakim Bunker Hill Memorial Bridge in Boston, Massachusetts is the widest cable-stayed bridge built prior to 2003. The bridge is part of the Big Dig, the largest overall highway construction project in the United States, and replaced the Charlestown High Bridge. According to the Massachusetts Turnpike Authority's web site, the bridge has an overall length of 436.5 m, a main span of 227.1 m, side spans of 81.4 m (downtown side) and 128.0 m (Charlestown side), and towers that are 82.3 m tall. In a cable-stayed bridge, instead of hanging the roadbed from cables slung over towers, the cables run directly between the roadbed...