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I-390 New York
76.06 miles ; from I-86 (formerly NY 17) near Avoca to I-490 west of Rochester. NY 390 continues north as a freeway. I-390 was finished in the early 1980s, and originally called the Genesee Expressway. 
On Nov. 24, 1971, I-390 was approved for inclusion in the interstate system, by transferring mileage from several cancelled interstates in the New York area: Lower Manhattan Expressway Spur, Cross Brooklyn Expressway, certain segments of the Nassau Expressway, the Clearview Expressway Extension, and the Queens Interborough Expressway. 
... the number was later used by Intel
Around that time, New York was actually planning to call the highway I-486, serving Rochester from the proposed I-86 (Southern Tier Expressway), which was then called NY 17. As it turned out, NY 17 stayed a state route until 1999, and at some time in the early 1970s I-486 became I-390.
Northward extension blocked
Construction on I-390 from Dansville north was blocked by environmental legislation was scheduled for 1975-1976, but blocked by environmental legislation. 
Brian W. Campbell writes: "Interstate 390 was supposed to have continued north... running parallel to Clinton Avenue up to Interstate 490 at Goodman Street. Original plans have interchanges at Elmwood and Clinton Avenues. Along 490 between Goodman Ave and Clinton Ave downtown, there is a wide patch of land parallel to the current 490 which would have been feeder lanes for 390. The project was cancelled in the 1970s, as it would have destroyed one of Rochester's nicer neighborhoods (Swillburg/South Wedge)."
The Rochester city council opposed the northward extension, and it was cancelled. I-390 was rerouted to meet intersect I-490 west of the city. This portion of I-390, together with I-590 east of the city and their state-numbered counterparts extending north of I-490, were formerly numbered NY 47 and named the "Outer Loop" in distinction to downtown's "Inner Loop".