Interstate 81 Main route of the Interstate Highway System
Length:	846 mi (1361 km)
South end:	I-40 in Dandridge, TN
Major junctions:	I-26 near Kingsport, TN I-64 from Lexington, VA to Staunton, VA I-70 in Hagerstown, MD I-76 near Harrisburg, PA I-84 near Scranton, PA I-86 / NY 17 in Binghamton, NY I-90 in Syracuse, NY
North end:	Ont 137 at Thousand Islands Bridge in Wellesley Island, NY/ON (TO Ont 401)

Interstate 81 (abbreviated I-81) is an interstate highway in the eastern part of the United States. Its southern terminus is at Interstate 40 in Dandridge, Tennessee; its northern terminus is on Wellesley Island (near Fishers Landing, New York) at the Canadian border, where the Thousand Islands Bridge connects it to Highway 401, the main freeway connecting Windsor-Detroit and Toronto to Montreal.

Interstate 81 largely traces the path of the Appalachian Mountains, often paralleling its older U.S. highway counterpart, U.S. Route 11. While mostly rural, it is heavily used as a trucking corridor, often as a bypass of the busier Interstate 95 to the east.

Also, there is a six state commission, the Interstate 81 Corridor Coalition, that was organized to handle issues along Interstate 81, such as truck traffic and air pollution. As of October 15, 2008, this commission has met twice.¹²

Route description

Tennessee and Virginia

Main articles: Interstate 81 in: Tennessee | Virginia

Interstate 81 begins in Tennessee at Interstate 40 in Dandridge. The route parallels the Appalachian Mountains for much of its route through Tennessee and Virginia, serving such cities as Roanoke, Blacksburg, Lexington, Staunton, Harrisonburg, and Winchester. In Harrisonburg, I-81 cuts through James Madison University. It parallels its older counterpart, U.S. Route 11, for its entire length in Virginia.

West Virginia and Maryland

Main articles: Interstate 81 in: West Virginia | Maryland

Interstate 81 briefly enters the eastern panhandle of West Virginia, serving the city of Martinsburg. It then traverses the state of Maryland at one of its narrowest points, passing through the "Hub City" of Hagerstown where it intersects with a large number of other routes.

Pennsylvania

Main article: Interstate 81 in Pennsylvania

Interstate 81 forms a major north-south corridor through the state of Pennsylvania, serving the boroughs of Chambersburg and Carlisle, where it meets the Pennsylvania Turnpike but does not interchange with it. Around the state capital of Harrisburg, the route forms the northeastern section of Pennsylvania's Capital Beltway. The route then travels northeast towards the Wyoming Valley, where it serves the cities of Wilkes-Barre and Scranton, then heads north through the Endless Mountains region towards the state line. Although it is signed as a North-South highway, it is distinctly Northeast-Southwest and occasionally east-west throughout the state.

New York

Main article: Interstate 81 in New York

Interstate 81 enters the New York state near Binghamton. It parallels U.S. Route 11 in a north-south direction, serving the cities of Syracuse (where it intersects the New York State Thruway), and Watertown. The route ends at the Canadian border at the Thousand Islands Bridge, where it crosses the St. Lawrence River, continuing as Highway 137.

Major intersections

• Interstate 40 near Dandridge, Tennessee, northeast of Knoxville
• Interstate 26 between the Tri-Cities, Tennessee
• Interstate 77 in Wytheville, Virginia. They stay joined for about 10 miles (16 km), and go in opposite directions (i.e., this is a wrong-way concurrency, where I-81 North overlaps I-77 South, and vice versa).
• Interstate 64 in Lexington, Virginia. They stay joined until Staunton, Virginia.
• Interstate 66 in Middletown, Virginia
• Interstate 70 in Hagerstown, Maryland
• Interstate 76 in Middlesex, Pennsylvania (near Carlisle, Pennsylvania)
• Interstate 83 in Harrisburg, Pennsylvania
• Interstate 78 in Bordnersville, Pennsylvania (near Jonestown, Pennsylvania)

Approaching the I-78/I-81 interchange in Union Township, Lebanon County, Pennsylvania).

• Interstate 80 in Saint Johns, Pennsylvania (near Hazleton, Pennsylvania)
• Interstate 476/PA Tpk NE Ext. in Dupont, Pennsylvania (near Pittston, Pennsylvania)
• Interstate 84 and Interstate 380 in Dunmore, Pennsylvania (near Scranton, Pennsylvania) Throop Dunmore Interchange
• Interstate 476/PA Tpk NE Ext.(again) in Clarks Summit, Pennsylvania
• 
  Future Interstate 86/NY 17 in Binghamton, New York
• Interstate 88 in Binghamton, New York
• Interstate 690 in downtown Syracuse, New York
• Interstate 90/New York State Thruway in North Syracuse, New York

Auxiliary routes

I-81 looking southbound near milepost 245 in Harrisonburg, Virginia.

There are three current child routes either providing access to, or bypassing, various cities along the Interstate 81 route.

Current

• I-381 - Bristol, Virginia
• I-581 - Roanoke, Virginia
• I-481 - Syracuse, New York

Past

• I-181 - Kingsport, Tennessee: Deleted in August 2005 when Interstate 26 took over I-181's entire length.
• I-81E - Current Interstate 380 (Pennsylvania)

v • d • e Auxiliary routes of Interstate 81 Tennessee: 181 (former) — Virginia: 381 • 581 — New York: 281 (former) • 481

References

External links

Wikimedia Commons has media related to: Interstate 81

• Thousand Islands Bridge System, showing the bridges and connections at the northern terminus
• Economic Development History of Interstate 81 in Virginia, a Federal Highway Administration report.

Main Interstate Highways (multiples of 5 highlighted)
4	5	8	10	12	15	16	17	19	20	22	24	25	26	27	29	30
35	37	39	40	43	44	45	49	55	57	59	64	65	66	68	69
70	71	72	73	74	75	76 (W)		76 (E)		77	78	79	80	81	82
83	84 (W)		84 (E)		85	86 (W)		86 (E)		87	88 (W)		88 (E)		89	90
91	93	94	95	96	97	99	(238)		H-1		H-2		H-3
Unsigned			A-1		A-2		A-3		A-4		PRI-1		PRI-2		PRI-3
Lists		Primary			Main - Intrastate - Suffixed - Future - Gaps
		Auxiliary			Main - Future - Unsigned
		Other			Standards - Business - Bypassed