Tappan Zee Hudson River Crossing Design-Build (The New NY Bridge Project)
The Tappan Zee Hudson River Crossing between Westchester and Rockland Counties in New York handles more than 138,000 vehicles every day—far more than its design capacity. A design-build project to replace the bridge will increase capacity and improve safety on the crossing. As the lead designer for the new Tappan Zee bridge, HDR is responsible for:
- Design project management
- Overall quality control including peer review and independent design check process
- Detailed design elements such as deep foundations, main span and approach span structures
- Highway elements including alignments, tolling and ITS
- Utilities and facility design
The new Tappan Zee Hudson River Crossing is designed for a 100-year service life and will be mass-transit-ready. It features twin three-mile structures, each with 1,200-foot cable-stayed main spans and 350-foot steel girder approach spans. The new bridge provides eight general traffic lanes, emergency lanes, extra-wide shoulders for express bus service, a dedicated bicycle and pedestrian path on the northern span, and scenic overlooks with anti-climb fencing and security cameras. A new toll plaza will include at least three highway-speed E-ZPass lanes. The project also includes plans for the approximately 35 existing buildings associated with the bridge.
The project team is following strict environmental performance commitments to protect the Hudson River estuary. State-of-the-art perimeter environmental monitoring stations have been installed near both the Rockland and Westchester County shorelines, allowing the team to monitor, minimize and mitigate potential adverse effects related to construction noise, vibration and air quality.
The design-build approach produced a savings of $1.7 billion compared with original state and federal cost estimates. The winning bid was at least 20 percent lower in cost than the other two bids submitted and offered the shortest construction time and required the least amount of dredging. The project is scheduled for completion in 2018.