the west side elevated highway (west side highway or miller highway, named for julius miller, manhattan borough president from 1922 to 1930) was an elevated section of new york state route 9a (ny 9a) running along the hudson river in the new york city borough of manhattan to the tip of the island. it was an elevated highway, one of the first urban freeways in the world, and served as a prototype for urban freeways elsewhere, including boston's central artery.