I-81

About I-81

From Dandridge, TN (I-40) to Wellesley Island, NY (Canada border)

Interstate 81 is a north-south route running about 855 miles from Dandridge, Tennessee, to the Canadian border in northern New York. It begins at Interstate 40 east of Knoxville and follows the Great Appalachian Valley northeast through Tennessee and Virginia, then crosses West Virginia and Maryland before traversing the length of Pennsylvania and central New York. At its north end it reaches Wellesley Island, where the Thousand Islands Bridge carries traffic across the Saint Lawrence River into Canada.

For much of its length the highway runs through the long, continuous valley west of the Blue Ridge, a natural corridor used for travel since colonial times. It serves the Tri-Cities of Tennessee, Roanoke and the Shenandoah Valley cities of Virginia, Hagerstown in Maryland, and Harrisburg, the Wyoming Valley, and Scranton area in Pennsylvania. In New York it runs north through Binghamton, Syracuse, and Watertown toward the border.

Because it provides a direct inland alternative to the congested Interstate 95 corridor along the coast, Interstate 81 carries an unusually high share of long-distance truck traffic. The combination of valley topography, frequent freight, and many at-grade communities along the way has made it one of the more heavily studied corridors in the eastern states.

State-by-state mileage

State	Miles
Tennessee	75.7
Virginia	324.9
West Virginia	26.0
Maryland	12.1
Pennsylvania	232.6
New York	183.6
Total	854.9

History

Interstate 81 was designated in 1957 as part of the original Interstate plan and was constructed in segments through the 1960s and into the 1970s. Its alignment closely followed the historic valley travel route long served by older U.S. highways.

The completed freeway tied together a chain of valley cities from eastern Tennessee to the Canadian border, becoming a principal inland north-south trucking corridor in the eastern United States.

Major cities and places

Notable features

• Thousand Islands Bridge

Did you know

• The southern terminus is at I-40 in Dandridge, Tennessee, and the northern terminus reaches the Canadian border in New York.
• It follows the Great Appalachian Valley for much of its route.
• The corridor serves as a major inland truck route parallel to I-95.
• At its north end the Thousand Islands Bridge links it across the Saint Lawrence River into Canada.