New Tappan Zee Bridge

Background

The original Tappan Zee Bridge is a cantilever bridge built during 1952–55. The bridge is 3 miles (4.8 km) long and spans the Hudson at its second-widest point. The Tappan Zee river crossing was named by 17th century Dutch settlers. The Tappan Zee Bridge, along with the smaller Bear Mountain Bridge, are the only crossings of the Tappan Zee, a 33-mile (53 km) stretch of river that passes through New York City's populous northern suburbs.

The deteriorating current structure bears an average of 138,000 vehicles per day, substantially more traffic than its designed capacity. During its first decade, the bridge carried fewer than 40,000 vehicles per day. Part of the justification for replacing the bridge stems from its construction immediately following the Korean War on a low budget of only $81 million. Unlike other major bridges in metropolitan New York, the Tappan Zee Bridge was designed to last only 50 years. The new bridge is intended to last at least 100 years.

The collapse of Minnesota's I-35W Mississippi River bridge in 2007 raised worries about the Tappan Zee Bridge's structural integrity. These concerns, together with traffic overcapacity and increased maintenance costs, escalated the serious discussions already ongoing about replacing the Tappan Zee with a tunnel or a new bridge. Six options were identified and submitted for project study and environmental review.

Construction progress

The Federal Highway Administration issued a report in October 2011 designating the Tappan Zee's replacement to be a dual-span twin bridge. The new bridge is now under construction a few yards to the north of the existing bridge, and will connect to the existing highway approaches of the New York State Thruway (I-87/I-287) on both river banks. Construction began as scheduled during 2013, with completion targeted for 2017. The project now has an estimated completion date of April 2018 at a cost of $3.98 billion.

Originally, it was thought that bridge tolls could more than double (to $12-$15 for automobiles, eastbound only), rising to those of New York City's Hudson River crossings. However, the state passed legislation freezing the toll on the bridge at $5 through 2020 in its 2016 legislative session.

The new Tappan Zee Bridge was proposed to include four vehicle lanes on each span, for a total of eight lanes, as well as a shared-use bicycle and pedestrian path. Like its predecessor, the new Tappan Zee Bridge will be administered by the New York State Thruway Authority. The authority is project co-sponsor, along with the state Department of Transportation.

The New York Metropolitan Transportation Council added the Tappan Zee Bridge to its list of projects eligible for federal funds in August 2012. The United States Department of Transportation approved the plan on September 25, 2012. The approval process took fewer than 10 months as opposed to the traditional multi-year process as a result of being placed on a "fast track" for approval by the Obama Administration. On December 17, 2012, New York state officials dropped their proposal for a 45 percent increase on the state Thruway toll for trucks, while advancing a $3.14 billion project to replace the bridge.

The new Tappan Zee Bridge is being built by Tappan Zee Constructors, a design-build LLC composed of Fluor Corporation, American Bridge Company, Granite Construction Northeast and Traylor Bros. The Left Coast Lifter will be used to install groups of pre-assembled girders one full span at a time. By the end of 2013, General Electric had completed four seasons of dredging to remove contaminants from the river bottom. Approximately 70 percent of the sediments targeted for dredging were removed (totaling more than 1,900,000 cubic yards (1,500,000 m³)of sediment).

The project timeline originally indicated that the old bridge would be closed in 2016 and that the demolition of the old bridge would begin in February 2017. That timeline has since been amended. The old bridge will be in service through "spring or summer" of 2017, when traffic will shift over to one of the spans of the new structure. The bridge's completion date of April 2018 remains unchanged.

When completed, the new Tappan Zee Bridge will be the one of the wider cable stay bridges on the planet, with a combined deck width across both asymmetric decks of almost 56 metres (184 ft) — barely one foot (30 cm) wider than the relatively "short-span", cable-stayed Leonard Zakim Bridge in downtown Boston, Massachusetts, itself already 183 feet wide. Turkey's 3rd Bosphorus bridge completed in 2016 has been built with a single deck almost 59 metres (194 ft) wide, and the Tappan Zee Bridge will also be one of the longest cable-stayed spans in the nation.

On July 19, 2016, a crane used for construction of the bridge collapsed onto the existing older bridge. Five people were injured, including three drivers and two bridge workers; no one was killed or critically injured.

Public transportation

West of the Tappan Zee, the 680,000 residents of Rockland and Orange counties currently have very limited mass transit to New York City via the Port Jervis Line and Pascack Valley Line commuter rail services. The bridge plan includes as an objective merely, "Providing a crossing that does not preclude future trans-Hudson transit services."

A proposed bus rapid transit system using the new bridge was shelved as too expensive. However, the bridge was structurally built for expansion of the BRT at a later date in mind. Also the new bridge is built to consider a later date expansion which would include a commuter rail. The existing Tarrytown station of the Metro-North Railroad's Hudson Line is located about 2,000 feet (610 m) from the new bridge's eastern landing. In 2011, the state estimated that a bus connector to the station would add about $151 million, or about 3 percent to projected costs of the new bridge.

Responding to widespread concerns about the lack of new public transit service, bridge planners agreed only to a "dedicated express bus lane" in each direction for use during rush hour.