High Quality Content by WIKIPEDIA articles! Interstate 390 (I-390) is a 75.86-mile (122.08 km) north–south auxiliary Interstate Highway located entirely within New York in the United States. The southern terminus of the route is at the Southern Tier Expressway (I-86 and New York State Route 17 or NY 17) in the town of Avoca. Its northern terminus is at I-490 (the Western Expressway) in Rochester. North of I-490, the expressway continues as NY 390 to the Lake Ontario State Parkway in Greece. I-390 connects to its parent, I-90 (the New York State Thruway), in Henrietta, a southern suburb of Rochester. The route is known as the Genesee Expressway from Avoca to I-590 in Brighton, where it becomes part of the Rochester Outer Loop.