<Tr> <Th_colspan="2"> Statistics </Th> </Tr> <Tr> <Th> Daily traffic </Th> <Td> 138,000 + (2011 est) </Td> </Tr> <P> The New Tappan Zee Bridge, also known as the New NY Bridge and officially named the Governor Mario M. Cuomo Bridge after the late former governor Mario Cuomo, is a twin cable - stayed bridge being built to replace the current original Tappan Zee Bridge over New York's Hudson River . The new bridges are to the north of and roughly parallel to the existing Tappan Zee Bridge, and cross the Hudson River in a parallel east - to - west direction . In the final configuration, the north span will carry the northbound traffic of I - 87, westbound traffic of I - 287, and a bicycle / pedestrian path, with the south span that will carry southbound and eastbound traffic of I - 87 and I - 287, respectively . Construction began in 2013, and at 1: 36 A.M. on August 26, 2017, the north span officially opened to westbound traffic . Eastbound traffic was switched onto the same span on October 6, 2017 . Tappan Zee Constructers are currently demolishing the old bridge and completing the south span, which eastbound traffic will use once complete . 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>

When did construction start on the new tappan zee bridge