into Manhattan on Broadway while US 9 used Riverdale Avenue north of 230th Street. As a result, the two routes would have had a short concurrency across Spuyten Duyvil Creek. NY 9A would have split to the south on Tenth Avenue at 218th Street in order to join the Harlem River Drive via Nagle Avenue and Dyckman Street. From there it would head west on 155th Street to Amsterdam Avenue, where it would head south to 79th Street, heading west there to rejoin US 9 at Riverside Drive. US 9 would have continued south through lower Manhattan to Staten Island via the Staten Island Ferry; however, it is unclear whether NY 9A would have continued south with US 9 to lower Manhattan. The New York Automobile Club released another plan in 1933. This plan made no changes to NY 9A; however, US 9 was changed to use Broadway all the way through the Bronx and to travel to New Jersey by way of the Holland Tunnel. In the final plan implemented in mid-December 1934, no route was assigned to the Harlem River Drive–Amsterdam Avenue corridor. Instead, NY 9A used what had been planned as US 9, splitting at Broadway and Dyckman Street. NY 9A ran south along the west side of Manhattan on Riverside Drive and the West Side Elevated Highway (detouring around an unfinished section via 57th Street, Eleventh Avenue and 48th Street) to end at the entrance and exit plazas of the Holland Tunnel. US 9 was shifted northward to enter New Jersey via the George Washington Bridge. Westchester County In Westchester County, Saw Mill River Road originally followed the Saw Mill River Parkway corridor from Eastview to Hawthorne. This section of Saw Mill River Road gained a number , becoming part of NY 142, a route that began at NY 100 on the Greenburgh–Mount Pleasant town line and followed Grasslands Road, NY 9A, and Saw Mill River Road north to Hawthorne, where it rejoined NY 100. The route went unchanged until it was removed . Its former routing was split into two routes—an extended NY 141 north of NY 9A and the new NY 100C along Grasslands Road—by 1940. NY 9A was extended northward from Tarrytown to Archville, a small hamlet midway between Tarrytown and Ossining, by way of Sleepy Hollow Road. Farther north, a new highway was built around Ossining from Saw Mill River Road (NY