The New York State Thruway Authority maintains 641 miles of roadway. This includes the 496-mile long Governor Thomas E. Dewey Thruway, the longest toll superhighway system in the United States . With the construction of the Thruway, Governor Dewey’s vision of a cross-State highway became a reality. This mainline provides the 426-mile connection between the State’s two largest cities, New York City and Buffalo , before extending westward to the Pennsylvania State line at Ripley.