Although not as old as other bridges such as the George Washington, the original Tappan Zee was built in the midst of a material shortage during the Korean War and was thus only designed to last for approximately fifty years.

The process to replace the bridge kicked off in 2012, with construction on the new spans beginning by contractor Tappan Zee Constructors in 2013.

[10] Built immediately after the Korean War, the bridge had a low construction budget of only $81 million and a designed life-span of only 50 years.

[13] 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.

[16]The Federal Highway Administration issued a report in October 2011 designating the Tappan Zee's replacement to be a dual-span twin bridge.

[18][19] The authority awarded a $3.142 billion contract to Tappan Zee Constructors (TZC), whose proposal was not only the least expensive but also promised the shortest construction timeline and included plans to minimize environmental impact.

[20][19] Originally, some motorists 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.

[17] The New York Metropolitan Transportation Council added the Tappan Zee Bridge to its list of projects eligible for federal funds in August 2012.

The Left Coast Lifter was used to install groups of pre-assembled girders one full span at a time.

[42][43] An opening ceremony was held on that date,[44][45] but the traffic shift itself was delayed when a piece of the old bridge came loose on September 7 while being demolished.

[48][49] The demolition of the old bridge started in November 2017 with the removal of the first steel section from the Rockland County approach.

A presentation by a whistleblower included allegations that the bolts had broken due to hydrogen embrittlement, which weakened the metal.

Engineering experts warned that the structural problems could compound, causing the girders to fall and the bridge to collapse.

[56] The issue was known as early as February 2016, when New York state officials had begun testing some bolts for breaks.

[56] Third-party consultant Alta Vista conducted its own study, concluding in late 2017 that hydrogen embrittlement was not the cause of the broken bolts.

[59][60] In response, the Federal Highway Administration issued a statement claiming it had "no safety concerns" with either of the Tappan Zee Bridge's spans.

[63] The NYSTA sued TZC in August 2024, claiming that around 61 of the 192 cables had been improperly installed and needed to be repaired.

[64][65] The new Tappan Zee Bridge is composed of two cable-stayed decks and has a total length of 16,368 ft (4,989.0 m; 3.1 mi; 5.0 km).

[3] The new spans equal the width of the relatively short-span, cable-stayed Leonard Zakim Bridge in Boston.

This path connects the towns of Tarrytown and South Nyack and measures 3.6 miles (5.8 km) in length.

Each belvedere is named after a local point of interest and provides Wi-Fi, a seating area, bike racks (on most), informational kiosks, and trash cans.

[75] Responding to widespread concerns about the lack of new public transit services, bridge planners agreed only to build one "dedicated express bus lane" in each direction for use during rush hour.

[82] This has been met with significant opposition from residents of nearby localities, largely due to the fact the new name did not include "Tappan Zee" like its predecessor; this name has been viewed as an homage to the Tappan tribe that inhabited the area as well as Dutch settlers who arrived during the 17th century.

[87][88] A Reclaim New York Initiative poll of Rockland and Westchester county residents found only 14.7% of respondents supported the new name.

[89][90] As of November 29, 2017, over 100,000 people had signed a Change.org petition called "Return the Cuomo Bridge its original name: The Tappan Zee.

[97] After Cuomo's resignation in August 2021, another bill to change the official name to "Tappan Zee Bridge" was proposed in the New York state legislature.