New York State Route 9A (NY 9A) is a state highway in the vicinity of New York City in the United States. Its southern terminus is at Battery Place near the northern end of the Brooklyn–Battery Tunnel in New York City, where it intersects with both the unsigned Interstate 478 (I-478) and FDR Drive. The northern terminus of NY 9A is at U.S. Route 9 (US 9) in Peekskill. It is predominantly an alternate route of US 9 between New York City and Peekskill; however, in New York City, it is a major route of its own as it runs along the West Side Highway and Henry Hudson Parkway. It is also one of only two signed New York State routes in Manhattan (the other is NY 25). In northern Westchester County, NY 9A follows the Briarcliff–Peekskill Parkway. The origins of NY 9A date back to the 1920s when an alternate route of then-NY 6 from Yonkers to Tarrytown was designated as NY 6A. NY 6 was redesignated as US 9 in 1927; however, NY 6A was not renumbered to NY 9A until the 1930 renumbering of state highways in New York. NY 9A was extended south into New York City in 1934 and north to Ossining in the late 1930s. In 1933, the Briarcliff–Peekskill Parkway opened as NY 404. All of NY 404 was incorporated into an extended NY 9A on January 1, 1949. NY 9A was extended northward to Peekskill in 1967 following the completion of the Croton Expressway and southward to the Brooklyn–Battery Tunnel in the mid-1990s. From Wikipedia
