The Governor Mario M Cuomo Bridge is a 3.1-mile cable-stayed twin-span bridge that replaced the 62-year old Tappan Zee cantilever bridge. The new bridge was built north of the existing bridge.

The average daily traffic on the old bridge was 138,000 vehicles, while the peak traffic was approximately 170,000 cars a day. The new Governor Mario M Cuomo Bridge will serve more than 140,000 motorists a day.

The bridge, traversing the Hudson River, carries the New York State Thruway and connects Rockland and Westchester counties.

Construction of the replacement bridge started in 2013 and the first span was opened in August 2017, while the second span was opened to traffic in September 2018. The estimated investment on the new bridge is $3.9bn. Pre-construction works for the project started in early 2013 and formal construction works started in October 2013.

The project was administered by the New York State Thruway Authority. Tappan Zee Constructors (TZC), a consortium of Fluor, American Bridge Company, Granite Construction and Traylor Bros acted as the design-build contractor for the project. The lead designer for the bridge is HDR.

Bridge replacement project background

Plans to replace the Tappan Zee bridge were first discussed in 1999. Approximately $750m was spent in maintaining the existing bridge during the last decade.

A new plan was fast-tracked in October 2011 followed by the signing of several approvals and agreements. The bridge construction proposals were submitted in July 2012 and the design-build plan was finalised in December 2012. The final contract approval was granted in January 2013.

Design and construction of the Governor Mario M Cuomo Bridge

The new cable-stayed twin-span bridge is designed to last for 100 years without requiring major structural maintenance. The bridge measures approximately 4.9km-long and features two 365m cable-stayed main spans with outwardly inclined main span towers and 107m steel girder approach spans. The angled towers rise about 419ft above the water and feature a chamfered-top. The towers support 192 stay cables made of more than 4,900 miles of steel strands.

The new bridge eases traffic congestion on the New York State Thruway as it features eight general traffic lanes, four emergency lanes, a bicycle and pedestrian path on the northern span, a commuter bus lane, anti-climb fencing, and security cameras. It also features a new toll plaza including at least three highway-speed E-Z pass lanes. The bridge was also constructed to cater to future bus transit, light rail and commuter rail services.

The weight of the structure and the number and size of foundations are minimised, and the dredge quantities are reduced from 1.8 million to less than one million cubic yards bringing down the environmental impacts, cost and construction duration. The bridge’s design reduced the number of piles required, while quieter vibration techniques for pile driving were employed. The concrete used in the construction of the piles was sourced from a floating batch plant on site.

The 400ft-long Left Coast Lifter floating crane, now nicknamed as ‘I Lift NY’ super crane, which was earlier used to construct the suspension span on the San Francisco – Oakland Bridge, carried out the lifting works for the new bridge. The crane will later be used to demolish the existing bridge.

Financing the $3.9bn bridge replacement project

A low-interest (3.89%) federal loan amounting to $1.6bn for the Governor Mario M Cuomo Bridge project was granted by the US Department of Transportation through its federal Transportation Infrastructure Finance and Innovation Act (TIFIA) programme.

Key players involved

Special inspections and materials testing for all the components of the bridge were carried out by Tectonic.

Quality assurance activities for the project were provided by Greenman-Pedersen and The LiRo Group. The project generated more than 600 jobs and benefited over 500 companies, which mostly comprise local and regional companies.