I81

Interstate 81 (I-81) is a major north–south Interstate Highway in the eastern United States. It follows the Appalachian Mountains, running from the southern border of Tennessee to the Canadian border in New York. The route spans roughly 855 miles (1,375 kilometers) and passes through six states: Tennessee, Virginia, West Virginia, Maryland, Pennsylvania, and New York.

Southern terminus and northern terminus

I-81 begins at an interchange with I-40 near Dandridge, Tennessee, and travels northward to the Canadian border in upstate New York. At the northern end, the highway continues into Canada as a continuation of the same corridor.

Route characteristics

The highway traverses a mix of rural mountain terrain and urban areas, serving as a primary corridor for freight and general travel. It provides key connections to numerous east–west routes and interstates at various junctions, and it runs through or near several regional cities. The route is largely toll-free.

History and designation

I-81 was designated as part of the original Interstate Highway System in the late 1950s. Construction and opening of segments occurred over the following decades, with many sections replacing or paralleling the older U.S. Route 11 corridor. Over the years, sections have undergone widening, interchange improvements, and safety enhancements to address increasing traffic and maintain efficiency.

Economic and regional role

As one of the eastern United States’ longstanding north–south corridors, I-81 connects the Northeast with the Southeast and Midwest regions, supporting freight movement, tourism, and regional economic activity along the Appalachian corridor.