The Governor Malcolm Wilson Tappan Zee Bridge, commonly known as the Tappan Zee Bridge, was a cantilever bridge in the U.S. state of New York. It was built from 1952 to 1955 to cross the Hudson River at one of its widest points, north of Midtown Manhattan, from South Nyack to Tarrytown. As an integral conduit within the New York Metropolitan Area, the bridge connected South Nyack in Rockland County with Tarrytown in Westchester County in the Lower Hudson Valley. Opened on December 15, 1955, the Tappan Zee Bridge was one of the primary crossings of the Hudson River north of New York City; it carried much of the traffic between southern New England and points west of the Hudson. The bridge was the longest bridge in New York State, a title retained by its replacement. The total length of the bridge approached . The cantilever span was , which provided a maximum clearance of over the water. The bridge was officially named after former governor Malcolm Wilson in 1994, though the original name continued to be used. The Tappan Zee Bridge was part of the New York State Thruway mainline and carried the highway concurrency of Interstate 87 and Interstate 287. The span carried seven lanes of motor traffic. The center lane was able to be switched between eastbound and westbound traffic depending on the prevalent commuter direction; on weekdays the center lane was eastbound in the morning and westbound in the evening. The switch was accomplished via a movable center barrier which was moved by a pair of barrier transfer machines. Even with the switchable lane, traffic was frequently very slow. In 2013, federal and state authorities started constructing a replacement bridge at a cost of at least $4 billion. All traffic was shifted to the new bridge on October 6, 2017, and demolition of the old bridge began soon afterward. The eastern half of the bridge was demolished in a controlled demolition on January 15, 2019, while the western half was lowered onto a barge and hauled away in May 2019. Name The Tappan Zee is named for an American Indian tribe from the area called "Tappan"; and zee being the Dutch word for "sea". In 1994, the name of Malcolm Wilson was added to the bridge's name upon the 20th anniversary of his leaving the governor's office in December 1974. However, it was almost never used