The $3.9 billion Tappan Zee Bridge replacement project will supplant an aging span between New York's Rockland and Westchester counties. The original cantilever bridge was completed in 1955, and plans for a replacement have been in the works for more than a decade. It is expected to be taken off line when the new bridge opens in 2016. Here's a closer look at the engineering behind the new plans, developed under New York State's first design-build contract. Read More