The 3.1-mile-long twin-span Governor Mario M. Cuomo Bridge replaced the Tappan Zee Bridge crossing over the Hudson, located fewer than 20 miles north of New York City. The $3.98 billion project was one of the largest-ever transportation design-build contracts in the United States and the largest bridge project in New York history. Designed for a 100-year service life, the bridge carries an enhanced regional bus service and has foundations sufficient for future commuter or light rail on structures between the two spans. The bridge provides greater traffic capacity while improving operations and safety for motorists crossing one of the widest parts of the Hudson River.

HDR was the lead designer on the New NY Bridge Design-Build project and a subcontractor for Tappan Zee Constructors, LLC, a consortium that includes Fluor Enterprises, American Bridge Company, Granite Construction Northeast and Traylor Bros.

The bridge features parallel 3-mile structures, each with a 2,230-foot cable-stayed main span and 10 five-span continuous approach units comprised of 350-foot steel girder spans. The bridge provides eight general traffic lanes, plus dedicated bus lanes and shoulders for emergency access. New tolling facilities with all-electronic toll collection have been implemented.

In addition to accommodating vehicular traffic, the new crossing includes a shared-use path (dedicated bicycle and pedestrian) on the northern span, with six scenic overlooks.

The project team followed strict environmental performance commitments to protect the Hudson River estuary. State-of-the-art environmental monitoring stations were installed near both the Rockland and Westchester shorelines. This equipment allowed the team to monitor, minimize and mitigate potential adverse effects from construction noise, vibration and air quality.

The new landmark crossing also led to the relocation, demolition and consolidation of 36 existing facilities associated with the bridge into two new multistory buildings: one a New York State Thruway Authority maintenance facility and the other a facility for New York State Police.