155th Street starts on the West Side at Riverside Drive, crossing Broadway, Amsterdam Avenue and St. Nicholas Avenue. At St. Nicholas Place, the terrain drops off steeply, and 155th Street is carried on a long viaduct, a City Landmark constructed in 1893, that slopes down towards the Harlem River, continuing onto the Macombs Dam Bridge, crossing over (but not intersecting with) the Harlem River Drive.Gray, Christopher. "Streetscapes/The 155th Street Viaduct; An Elevated 1893 Roadway With a Lacy Elegance", The New York Times, July 9, 2000. Retrieved November 10, 2007. A separate, unconnected section of 155th Street runs under the viaduct, connecting Bradhurst Avenue and the Harlem River Drive.
