Interstate 86 (west)

Interstate 86 (I-86) is an intrastate Interstate Highway, located entirely within the state of Idaho. It runs 63 miles (101.4 kilomters) from an intersection with Interstate 84 located approximately 7 miles (11.3 kilometers) east of Declo in rural Cassia County, to an intersection with Interstate 15 at Pocatello. Interstate 86 connects the major eastern Idaho cities of Pocatello and Idaho Falls with the state's Magic Valley region.

Interstate 86 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. (See Interstate 86 (east).) There was also an Interstate 15E in California at the time.

Besides being somewhat short, the area Interstate 86 passes through is very desolate. Pocatello and American Falls are the only incorporated settlements located on the highway. Between American Falls and Pocatello I-86 passes through a portion of Fort Hall Indian Reservation.

Interstate 86 (east)

Interstate 86 (I-86) is an Interstate Highway in the U.S. states of New York and Pennsylvania. It is an upgrade of the existing New York State Route 17. Known as the Southern Tier Expressway and Quickway (split by Interstate 81 at Binghamton, New York), the route will connect Interstate 90 near Erie, Pennsylvania, with Interstate 87 (New York State Thruway) near Harriman, New York. As of October 2006, it runs east from I-90 to New York State Route 14 in Horseheads (near Elmira). In September 2006, a 9.9 mile section of New York State Route 17 just east of Binghamton (between Exits 75 and 79) was designated as I-86, bringing the total length of highway designated as I-86 to 195 miles (with only 186 miles remaining to be designated). Once completed, I-86 will stretch 388 miles (624 km) across the Southern Tier of New York from I-90 to I-87, shorter than the 460 miles (740 km) along the flatter New York State Thruway to the north. The remaining segment of NY-17 will then be essentially a north-south extension of a New Jersey route with the same number, terminating in the New York City suburbs.

Several sections of NY 17 are not up to freeway or Interstate standards, and need to be upgraded before I-86 can be designated along its full length. These substandard sections are located near Elmira, Binghamton, and the Catskill Mountains.

I-86 currently travels 6.99 miles (11.25 km) in Pennsylvania and 184.6 miles (297.1 km) in New York. Except for a section of about 1.5 miles (2.5 km) that dips into Pennsylvania near Waverly, New York but is maintained by the New York State Department of Transportation, the rest of I-86 will be in New York.

The Southern Tier Expressway section west of Binghamton is also Corridor T of the Appalachian Development Highway System. An extension of the U.S. Route 219 Southern Expressway will also join Interstate 86.

west map, east map