The Western Interstate 86 is an intrastate Interstate, located entirely within the state of Idaho. It runs from an intersection with Interstate 84 in Heyburn, Idaho to an intersection with Interstate 15 at Pocatello, Idaho.
The Eastern Interstate 86 runs from an intersection with Interstate 90 in Erie, Pennsylvania to Elmira, New York at the border between Chemung County, New York and Steuben County, New York along what was formerly New York State Highway 17. It will be extended eastward to an intersection with Interstate 87 once key improvements in the Elmira, Binghamton, and Catskills areas are completed.
I-86 was also used to refer to what is now I-84 between Manchester, Connecticut and I-90 in Sturbridge, Massachusetts; this was done so that I-84 could continue from Manchester to Providence, Rhode Island. After environmental opposition "killed" that leg of I-84, I-86 was also deemed surplus to requirements.
Interstate86 is an intrastate Interstate Highway, located entirely within the state of Idaho.
Interstate86 connects the major eastern Idaho cities of Pocatello and Idaho Falls with the state's Magic Valley region.
Interstate86 was originally numbered as Interstate 15W in the 1970s, however AASHTO decided it was better to have duplicate numbers in different parts of the country instead of having suffixes.