Interstate 86 (I-86): Both Roads, Where They Run, Miles and Safety Data

How long is I-86?

The January 2026 FHWA Route Log gives I-86 316.99 miles across both roads. Idaho's road accounts for 62.83 of them. The eastern road has 254.16: 8.49 miles in Pennsylvania and 245.67 in New York. The Route Log books no shared pavement to either road, so the crash rates further down use these same state figures.

Wikipedia lists 62.85 miles for the Idaho road and 254.02 for the eastern one, within a fraction of a mile of the federal totals. The two part ways on the state split. Wikipedia has 7.00 miles in Pennsylvania and 247.02 in New York, so the Route Log's Pennsylvania row comes out 1.49 miles longer and New York's 1.35 miles shorter. Wikipedia's New York figure includes the 10.02-mile detached segment between Kirkwood and Windsor. Interstate Guide still prints 223.39 miles for the eastern road from the December 2021 Route Log, which predates the 32 miles New York added from Waverly to exit 67 in November 2024.

Where I-86 starts and ends

The western I-86 begins at a junction with I-84 and US 30 northeast of Declo in Cassia County, Idaho. US 30 stays with it nearly the whole way and splits off just west of Pocatello at exit 58. From Raft River the freeway follows the Snake River and Lake Walcott northeast to American Falls, passing Massacre Rocks State Park and American Falls Reservoir along part of the Oregon Trail corridor. It then passes the Fort Hall Indian Reservation and ends at I-15 on the north edge of Pocatello, in Chubbuck. Wikipedia counts it among the shortest two-digit Interstates in the lower 48.

The eastern I-86 leaves I-90 at exit 37 in Greenfield Township, Pennsylvania, east of Erie, and reaches New York after about seven miles (8.49 in the Route Log). It crosses Chautauqua Lake on the Chautauqua County Veterans Memorial Bridge, passes Jamestown and runs through the Allegany Indian Reservation around Salamanca on its way to Olean, Hornell, Corning and Elmira. I-390 ends at it near Avoca (exit 36), and I-99 ends at it near Painted Post (exit 44A). Past Waverly and Owego, the designated main road stops at exit 67, NY 26, in Vestal. NY 17 continues through Binghamton without the I-86 number, which picks up again on a separate stretch from I-81 at exit 75 in Kirkwood to NY 79 at exit 79 in Windsor. New York plans to carry I-86 along NY 17 all the way to the Thruway in Orange County.

Interstate junctions along I-86

The list reads west to east and starts with the Idaho road, which meets I-84 at its western end and I-15 at Pocatello. The eastern road follows, beginning with I-90 near Erie and then I-99 near Corning. The final entry, I-81 at Kirkwood, belongs to the detached segment east of Binghamton, so the main road never meets I-81 while it carries the I-86 number. Between the two roads that makes five different Interstates. I-390, a three-digit route that ends at I-86 near Avoca, is left out of the list.

Fatal crashes on I-86

Crashes on the I-86 main line killed 34 people from 2020 through 2024, about 7 a year on both roads together. That comes to 2.1 deaths per 100 route miles a year, under a quarter of the 9.5 Interstate average. I-86 places 55th of 56 ranked routes, so only one Interstate has a lower rate. Yearly deaths went 2, 5, 10 and 13 from 2020 to 2023, then dropped to 4 in 2024, the year covered by NHTSA's preliminary file.

Idaho's 62.83 miles recorded 12 deaths, a rate of 3.8, the higher of the two states with a rate. New York had 21 deaths on 245.67 miles, a rate of 1.7. Pennsylvania's single death came on 8.49 miles, too short a stretch for a rate. Cassia County, Idaho, where the western road begins, leads the county list with 7 deaths, and Power County, also in Idaho, has 4. In New York, Chemung County had 6, and Chautauqua and Steuben counties had 5 each.

Counties with the most I-86 crash deaths

Bridges on I-86

The 2025 National Bridge Inventory counts 321 bridges carrying the I-86 main line, with a median construction year of 1973. Of those, 110 rate Good, 205 Fair and 6 Poor, about 1.9 percent. New York has 273 of the bridges and all 6 of the Poor ones. None of Idaho's 44 bridges or Pennsylvania's 4 rate Poor.

Idaho has rebuilt both ends of its road in recent years. A $20 million project that began in May 2018 reworked the 1960 trumpet interchange with I-84 and wrapped up in the winter of 2020. At Pocatello, the I-86 and I-15 system interchange got $112 million of construction from mid-2022 to the summer of 2025, which replaced bridges Interstate Guide describes as functionally obsolete.

Tolls on I-86

Neither I-86 has an entry in FHWA's inventory of toll roads, bridges and tunnels as of January 1, 2023, and none of the sources for this guide mention tolls added since. Wikipedia describes NY 17 and I-86 across the Southern Tier as a toll-free alternative to the New York State Thruway. A through trip on the Idaho road or the eastern road costs nothing in tolls.

How the I-86 number landed in Idaho and New York

Idaho's road carried two other numbers first. A 1957 proposal called it I-82N, and it became I-15W in 1958. On July 6, 1977, AASHTO conditionally approved a swap that turned I-15W into I-86 and I-80N, the road it meets at Declo, into I-84; Wikipedia dates the renumbering to 1978. Openings stretched from 1959 to 1985. The American Falls bypass was done in October 1959, the Chubbuck section opened in July 1968, and the stretch from American Falls to the Pocatello airport followed in September 1972. The last four-lane section, from Raft River to American Falls, was dedicated on October 11, 1985.

The eastern road started as NY 17, the Southern Tier Expressway, whose first pieces opened in the mid-1960s. After a 1967 test filling of the Kinzua Dam's Allegheny Reservoir put part of the old highway underwater, New York built a new freeway between Coldspring and Salamanca. East of Salamanca, Seneca objections to the route through the Allegany reservation delayed exits 20 to 24. A 1976 agreement cleared the way, protesting Senecas stopped construction on July 21, 1985, and a temporary injunction let it resume on August 13. The Seneca Junction to Allegany section was open by 1995. From I-90 to exit 8 near Sherman, New York, the road opened as a super two by 1989 and got its westbound lanes on October 2, 1997.

AASHTO approved a Future I-86 designation for the New York corridor on November 6, 1998. On December 3, 1999, FHWA applied it to all of Pennsylvania Route 17 and the westernmost 177 miles of NY 17, as far as exit 48 in East Corning. Extensions reached NY 14 in Horseheads in January 2004, NY 352 in Elmira in March 2008 and Waverly (exit 60) in July 2013. The Kirkwood to Windsor segment got the number on May 1, 2006, and the 32 miles from Waverly to exit 67 followed on November 14, 2024. Interstate Guide notes that the whole eastern route is named the Daniel Patrick Moynihan Interstate Highway. The number also had an earlier life in New England: until May 23, 1984, I-86 was the road from East Hartford, Connecticut, to Sturbridge, Massachusetts, which is now part of I-84.

I-86 traffic and road conditions

For a crash, closure or snow report on I-86 right now, open the traveler site for the state you are driving in. Idaho's covers the western road, and the Pennsylvania and New York sites cover the Southern Tier road from Erie to Windsor.

I-86 questions