Interstate 81 (I-81): Route, State Miles, Safety and Bridge Data

How long is I-81?

The January 2026 FHWA Route Log lists I-81 at 781.30 miles. Wikipedia and Interstate Guide both print 855.02, and Interstate Guide credits its table to the Route Log of December 31, 2021. Almost all of the 73.72-mile gap sits in one row. The current log gives Tennessee 1.96 miles, where the older figures give 75.66. The other five states agree to within a tenth of a mile, so the Tennessee entry looks like a misprint in the newer log. The crash rates on this page count Tennessee at 75.66 miles.

Virginia has the most I-81 mileage at 324.92 miles, about two-fifths of the route by either total. That figure takes in the 30.40 miles shared with I-64 between Lexington and Staunton and the 8.80 miles shared with I-77 near Wytheville; the Route Log rows for I-64 and I-77 mark those stretches as running on I-81. Pennsylvania is second with 232.74 miles and New York third with 183.66. Leaving aside the misprinted 1.96-mile Tennessee row, Maryland's 12.02 miles around Hagerstown are the shortest state piece.

Where I-81 starts and ends

The southern end is a directional T interchange with I-40 near Dandridge, Tennessee, northeast of Knoxville. The northern end is the Canadian border on Wellesley Island, New York, where a 90-foot bridge crosses the International Rift to Hill Island. Ontario Highway 137 carries traffic on for 2.7 miles to Highway 401.

Between the two, I-81 passes Bristol, Harrisonburg, Winchester, Hagerstown, Chambersburg, Harrisburg, Scranton, Binghamton, Syracuse and Watertown, and the I-581 spur takes traffic into Roanoke. US 11 runs beside it for the full length of Virginia. In Binghamton it shares pavement with NY 17, a stretch planned to carry I-86 as well.

Interstate junctions along I-81

The list reads south to north, starting with I-40 at Dandridge and ending with I-90 in New York. I-64 shows up twice, once at each end of the stretch the two routes share between Lexington and Staunton. I-77 also rides with I-81 near Wytheville but has a single entry. Maryland's 12.02 miles hold one crossing, I-70 at Halfway. Pennsylvania has more entries than any other state: I-76, I-83, I-78, I-80 and I-84.

Fatal crashes on I-81

Crashes on the I-81 main line killed 352 people from 2020 to 2024, about 70 a year. That comes to 8.2 deaths per 100 route miles each year, below the 9.5 average for all Interstates, and I-81 ranks 27th highest of the 56 routes long enough to rate. The rate counts Tennessee at 75.66 miles, the figure Wikipedia and Interstate Guide give, because the Route Log's 1.96-mile Tennessee row looks like a misprint. Yearly deaths stayed between 71 and 75 from 2020 to 2022, dipped to 63 in 2023 and came back to 70 in 2024.

West Virginia's 26.00 miles have the worst rate on the route at 16.9, and all 22 of the state's deaths happened in Berkeley County, which tops the county list. Virginia had 153 deaths and Pennsylvania 107, at rates of 9.4 and 9.2. New York's 183.66 miles are the safest by this measure at 2.8. Franklin County, Pennsylvania, and Augusta and Wythe counties in Virginia come next with 19 deaths each, followed by Lebanon County, Pennsylvania, with 16. Tennessee's 33 deaths over 75.66 miles work out to 8.7, fourth of the five states with a rate. Maryland had 11 deaths on 12.02 miles, too short a piece to rate.

Counties with the most I-81 crash deaths

Bridges on I-81

The 2025 National Bridge Inventory counts 933 bridges carrying the I-81 main line, with a median build year of 1965. Forty rate Poor, about 4 percent, and 151 rate Good. New York has the most Poor ratings, 18 of its 181 bridges, or about one in ten. Pennsylvania follows with 16 of 284. Virginia has the most bridges of any state at 331, and only 4 of those rate Poor. Tennessee's 102 bridges, 2 of them Poor, are one more sign that the 1.96-mile Route Log row is a misprint.

At the north end, I-81 crosses the St. Lawrence on the Thousand Islands Bridge, dedicated on August 18, 1938, 19 years before the route got its number. The span from the mainland to Wellesley Island is one of the few two-lane stretches left on the Interstate system. In Syracuse, New York is taking down the 1.4-mile elevated viaduct downtown, built in the 1950s and 1960s.

Tolls on I-81

FHWA's January 2023 toll inventory lists one facility on I-81, the Thousand Islands Bridge, run by the Thousand Islands Bridge Authority. That bridge is the only place on I-81 where FHWA records a toll, so a trip that turns off before Canada pays nothing from Tennessee to the St. Lawrence.

FHWA gives the facility as 5.2 miles, from Collins Landing, New York, to Ivy Lea, Ontario. That figure covers the whole bridge system, and 4.3 of those miles are on the Ontario side, past the point where I-81 ends at the border.

I-81 auxiliary routes

Four three-digit routes carry I-81's number. I-581 runs 6.64 miles into Roanoke, and I-381 is a 1.39-mile spur in Bristol, Virginia. In New York, I-481 bypasses Syracuse for 15.14 miles through DeWitt, and the 4.52-mile I-781 connects I-81 near Watertown with Fort Drum. On September 22, 2026, FHWA approved redesignating I-481 as I-81 and the old route through downtown as Business Loop 81, with signs changing over. An earlier spur, I-181 near Kingsport, Tennessee, was folded into I-26 between 2003 and 2007.

Building I-81 and rerouting it at Syracuse

The corridor shows up in the National Interregional Highway Committee's 1944 report, and the I-81 number was assigned on August 14, 1957. Virginia started work late that year near Buchanan, opened its first four miles in 1959 and finished its last section on December 21, 1971. West Virginia completed both of its segments on October 19, 1966, and New York opened its final 17 miles on October 18, 1968.

Tennessee partly opened its last section on December 20, 1974, then opened all four lanes on August 27, 1975. Wikipedia dates the finish of the whole route to September 11, 1975, when Pennsylvania's last section opened, while Interstate Guide has Pennsylvania opening pieces from 1960 to 1976. In 1987 Maryland dedicated its stretch as the Maryland Veterans Memorial Highway, and that July the section shared with I-77 at Wytheville was brought up to Interstate standards. Six states formed the I-81 Corridor Coalition in 2007.

The Syracuse viaduct was built through a historic African American neighborhood. New York picked the Community Grid plan in April 2019, which moves I-81 onto the I-481 bypass and takes the downtown viaduct out, leaving the old route as Business Loop 81. AASHTO gave conditional approval to the new route numbers in May 2021, and FHWA approved the change on September 22, 2026: I-481 is now I-81 and the downtown route becomes Business Loop 81, with signs changing over. Construction began in 2023, and the viaduct is due to close to traffic around the end of 2026 so it can be taken down. Published cost figures range from $1.9 billion to $3.6 billion. Interstate Guide reports that the ramp from I-81 north to I-690 east was scheduled to close permanently on November 16, 2026.

I-81 traffic and road conditions

Each state along I-81 posts wrecks, closures and work zones on its own traveler page, so check the one for the stretch you are heading into. They are linked below in route order, starting with Tennessee's SmartWay and ending with 511NY.

I-81 questions