<P> The Tappan Zee Bridge, officially named the Governor Mario M. Cuomo Bridge after former New York Governor Mario Cuomo, is a twin cable - stayed bridge being built to replace the original Tappan Zee Bridge over New York's Hudson River . The new twin spans will be located to the north of--and roughly parallel to--the existing Tappan Zee Bridge, crossing the Hudson River in a parallel east--west direction . </P> <P> In the new bridge's final configuration, the north span will carry the northbound and westbound automobile traffic of I - 87 and I - 287; it will also carry a shared - use path for bicycles and pedestrians . The south span will carry the southbound and eastbound automobile traffic of I - 87 and I - 287 . </P> <P> Tappan Zee Constructors began construction in 2013 . The north span officially opened to westbound traffic on August 26, 2017; it also opened to eastbound traffic on October 6, 2017 . Tappan Zee Constructors then began demolishing the old bridge . Eastbound traffic will be switched to the south span upon its completion . Both spans are expected to be operational by June 15, 2018 . </P> <P> The original Tappan Zee Bridge was a cantilever bridge built during 1952--1955 . The bridge was 3 miles (4.8 km) long and spanned 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 stretch of the Hudson between Westchester and Rockland counties, both of which are part of New York City's populous northern suburbs . </P>

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