Additional Info


State Tennessee
Mileage 75.66
Cities Morristown, Kingsport, Johnson City, Bristol
Junctions Interstate 40, Interstate 181/Future Interstate 26
State Virginia
Mileage 324.92
Cities Bristol, Marion, Wytheville, Christiansburg, Roanoke, Lexington, Staunton, Harrisonburg, Winchester
Junctions Interstate 381, Interstate 77/Future Interstate 74, Interstate 77, Future Interstate 73, Interstate 581/Future Interstate 73, Interstate 64, Interstate 64, Interstate 66
State West Virginia
Mileage 26.00
Cities Martinsburg
Junctions None
State Maryland
Mileage 12.08
Cities Hagerstown
Junctions Interstate 70
State Pennsylvania
Mileage 232.63
Cities Chambersburg, Shippensburg, Carlisle, Harrisburg, Frackville, Mahanoy City, Hazelton, Wilkes-Barre, Scranton
Junctions Interstate 76, Interstate 83, Interstate 78, Interstate 80, Interstate 476, Interstate 84/380, Interstate 476
State New York
Mileage 183.60
Cities Binghamton, Cortland, Syracuse, Watertown
Junctions Future Interstate 86, Interstate 88, Interstate 481, Interstate 690, Interstate 90, Interstate 481
TOTAL 854.89
Source: December 31, 2015 Interstate Route Log and Finders List
Interstate 81 Annual Average Daily Traffic

State Location AADT Composite Year
Tennessee White Pine 37,200 2002
Tennessee Blountville 23,880 2002
Virginia Bristol 50,000 2002
Virginia Rural Retreat 24,000 2002
Virginia Wytheville 53,000 2002
Virginia Roanoke 72,000 2002
Virginia Staunton 59,000 2002
Virginia Harrisonburg 51,000 2002
Virginia Winchester 55,000 2002
Maryland Hagerstown 56,825 2002
Pennsylvania Harrisburg 84,000 2002
Pennsylvania Lickdale 23,000 2002
Pennsylvania Hazelton 43,000 2002
Pennsylvania Wilkes-Barre 59,000 2002
Pennsylvania Scranton 77,000 2002
New York Binghamton 72,100 2002
New York Syracuse 90,700 2002
New York Watertown 23,400 2002
New York Wellesley Island 5,500 2002
Source: Traffic Flow Maps - Tennessee Roads and Streets 2002 (TDOT)
Virginia Department of Transportation 2002 AADT
2002 AADTS Report (Maryland Department of Transportation State Highway Administration - Highway Information Services Division)
Pennsylvania Traffic Volumes 2002 (Penndot)
NYSDOT 2002 Traffic Volume Report
Complete Interstate 81 AADT data.
Northeastern Tennessee - 1970 Tennessee Official Highway Map.
The southernmost 12 miles of Interstate 81 and the short stretch leading into Virginia were open to traffic by 1970. Per the 1973 Tennessee Official State Map, all of I-81 was under construction, with the route open northward to U.S. 11E near Mohawk Crossroad and southward to SSR 126 at Blountville.
Interstate 81 between the I-78 and I-80 corridors - 1965 Pennsylvania Official Highway Map.
Construction was underway from Exit 145 northward to the Butler Drive overpass along I-81 in 1965. The stretch would open between PA 93 (former PA 29) north to I-80 in 1967.2
Interstate 81 corridor through Upstate New York - 1963.
Segments of I-81 open by 1963 included the portion from Park Street and Onondaga Lake Parkway (NY 370) in Syracuse to New York 342 (former NY 181) north of Watertown and a bypass of U.S. 11 to the west of La Fayette. Additionally the Thousand Islands Bridge, dedicated on August 18, 1938, was incorporated as the I-81 connection to Ontario, Canada.


Interstate 81


Following the spine of the Appalachian Mountains, Interstate 81 provides a link between the Northeastern Megalopolis to points in the Southeastern States and Tennessee Valley, adding to its appeal as a major trucking route. Interstate 81 does not enter major metropolitan areas; it instead serves smaller cities such as Roanoke and Winchester, Virginia; Hagerstown, Maryland; Harrisburg and Scranton, Pennsylvania; and Binghamton and Syracuse, New York. After passing through Watertown, Interstate 81 crosses the St. Lawrence Seaway to meet Ontario 401 in Canada.

Parallel U.S. Routes

U.S. 11 parallels freeways for the majority of route from New Orleans north to Watertown, New York. I-81 runs along the US highway from east of Bristol, Virginia through to Upstate New York, with the exception of between Harrisburg and Wilkes-Barre, Pennsylvania. Through Tennessee, U.S. 11 partitions into the branches of 11E and 11W, along the Interstate 81 corridor between Knoxville and Bristol. U.S. 22 also parallels the freeway from Harrisburg northeast to I-78 near Jonestown, Pennsylvania.


Tennessee's portion was completed by 1975.4 Further north in Virginia, Interstate 81 opened between November 1959 and July 1987. The first portion of any Interstate highway opened in West Virginia was the segment of I-81 through Berkeley County in 1961.7 The Maryland portion of Interstate 81 first opened in 1962 between U.S. 40 and the Maryland state line. Completion of the southern segment within the Free State followed by the mid 1960s.3

Interstate 81 within Pennsylvania opened in segments between 1960 and 1976.2 Within New York, Interstate 81 was established in 1957, with construction completing the route between 1967 and 1969.5

A branch route of Interstate 81 was designated from Scranton southeast to Pocono Township in northeastern Pennsylvania. Initially proposed as part of Interstate 82 by Pennsylvania on August 14, 1957, the route was renumbered by AASHO on June 27, 1958 as Interstate 81S.6 This later was renumbered again to Interstate 81E and ultimately to Interstate 380 as confirmed by AASHTO on June 20, 1972.

Tolling Interstate 81 in Virginia

Discussed by the state of Virginia in December 2003 was the idea of how to best expand Interstate 81 throughout the Commonwealth. Several proposals emerged due to the state's Public-Private Transportation Act. Of these, two concepts were considered the front runners:

  • Star Solutions Proposal. Expand Interstate 81 to eight overall lanes with a separation between car and truck lanes. This major overhaul was estimated to cost upwards of $10.9 billion and to be funded with truck tolls, which were legalized on trucks by the Virginia General Assembly in 2001.
  • Fluor Virginia Proposal. Expand Interstate 81 to six lanes, with the implementation of car and truck tolls. Notably, car tolls were not legally permitted on existing Interstate highways in Virginia at the time. This concept entailed a $7 billion pricetag.

The major concern with the first option was that creator of the plan to expand the freeway to eight lanes, Star Solutions, included a request for a "noncompete" clause in its contract. That meant that VDOT was disallowed from undertaking any new projects that would increase the capacity or overall improve any highways within the I-81 corridor for the 40-year life of the Interstate 81 bonds. This red tape would have impacted U.S. 11, U.S. 29 and Interstate 95 among other north-south routes in the state.

Under the Fluor Virginia concept, issues arose with the concept of tolling cars. While tolls were legal for trucks, they remained prohibited on automobile traffic, requiring an amendment by the General Assembly for the Fluor Virginia plan to go forward.1

With either option, construction was not expected to begin until at least 2007. However subsequent developments led to the cancellation of all proposals related to tolling Interstate 81.

Highway Guides

Southern Terminus - Interstate 40 - near Dandridge, Tennessee
Perspective from Interstate 81 south
Traffic merges from Exit 4/Tennessee State Secondary 341 in time to see the two mile guide sign for the southern terminus - Interstate 40. Photo taken by Chris Patriarca (2003).
This sign bridge originally held separate panels for Exits 1A/B. With the roadwork completed in the late 1990s, this diagrammatic sign replaced those two panels. One lane is allocated for Interstate 40 eastbound to the Great Smokey Mountains and Asheville, North Carolina. Photo taken by Chris Patriarca (2003).
Interstate 81 southbound concludes at Exits 1A/1B for Interstate 40. Since Interstate 81 is orientated in a northeast/southwest direction, traffic is defaulted onto Interstate 40 westbound towards Knoxville and Interstate 75. Knoxville is just a 30 mile drive westward from this interchange. Photo taken by Jeffrey Napier (01/02).
Closer look at the Interstate 40/Exits 1A/B sign panels at the southern terminus. Interstate 40 between Nashville and Interstate 75 and again east of Interstate 81 is quite scenic. Interstate 81 northeast to the Virginia state line is equally as scenic. Photo taken by Chris Patriarca.
Perspective from Interstate 40 west
Two mile guide sign on Interstate 40 westbound for Exit 421/Interstate 81 northbound. Traffic counts take a shot in the arm as the two Interstates merge and Interstate 40 migrates towards Knoxville. Interstate 81 is a major trucking corridor between the southeast and northeast U.S. accordingly. Photo taken by Jeffrey Napier (01/02).
Interstate 81 serves the Tri-Cities region of northeastern Tennessee with Bristol the chosen control city of the three (Johnson City and Kingsport the other two members). This sign bridge is located one mile from the Interstate 40/81 interchange. Photo taken by Jeffrey Napier (01/02).
Reconstruction of Interstate 40 occurred between Knoxville and Interstate 81 in the late 1990s. The highway was resurfaced, saw safety improvements and widening, and received new guide signage for the Interstate 81 interchange. This video capture looks at the same overheads that are in the above photograph. Vidcap taken 08/07/99.
Yet a third view of the Interstate 40/81 sign bridge on Interstate 40 westbound, one mile before the interchange of Exit 421. Interstate 81 between Interstate 40 and Bristol is a scenic drive with many views of the Appalachian Mountains. Photo taken by Jim K. Georges (07/98).
Finally, Interstate 40 reaches Exit 421/Interstate 81 north. Results of the aforementioned reconstruction are evident in the guard rail design of the Interstate 40 overpass over the Interstate 81 northbound beginning from eastbound. Photo taken by Jeffrey Napier (01/02).
A closer view of the guide signage on Interstate 40 west at Exit 421. The city of Bristol is situated partially in Tennessee and partially in Virginia. The downtown portion of the city is 80 miles to the northeast via Interstate 81. Vidcap taken 08/07/99.
With older pavement in place, Interstate 40 westbound at Exit 421/Interstate 81 north for a third time. Interstate 40 merges with Interstate 75 at Exit 385, 36 miles to the west. Photo taken by Jim K. Georges (07/98).
Next Three Interstate Junctions for Interstate 40 west
Interstate 640 28 miles at east Knoxville, TN
Interstate 275 34 miles at downtown Knoxville, TN
Interstate 75 overlap begin/
Interstate 640
36 miles at Knoxville, TN
Perspective from Interstate 40 east
Results of the late 1990s construction of Interstate 40 include widening of the freeway from four to six lanes and the construction of the high-walled jersey barrier median. This photo looks at the two mile guide signage that was also installed during the same project. Photo taken by Jeffrey Napier (01/02).
Rolling hills guide Interstate 40 eastward to Interstate 81 north/Exit 421. The control point for Interstate 40 is that of Asheville, a city of nearly 70,000 residents to the east of the Bald and Great Smoky Mountains. Photo taken by Jeffrey Napier (01/02).
Before Interstate 40 eastbound expanded from two to three lanes, this set of guide signs directed motorists for the Exit 421/Interstate 81 split. This style of signage still graces sign bridges over Interstate 40 westbound, as that stretch of Interstate carries just four lanes. Photo taken 05/29/95.
With the widening of Interstate 40, this directional guide signage was installed, indicating that the left-hand lane becomes exit-only for Interstate 81 north. Similar to adjacent states of Alabama, Georgia, and Mississippi, sign lighting is no longer used. Photo taken by Jeffrey Napier (01/02).
This set of nondescript guide signs once directed motorists one-half mile ahead of the Exit 421 interchange. They were replaced between 1995 and 1998 during reconstruction. Vidcap taken 05/29/95.
As evident by the amount of traffic in this scene, the widening of Interstate 40 was a welcome change. Here Interstate 81 departs towards the Tri-Cities on the left while Interstate 40 turns southeasterly for its crossing of the Great Smoky and Bald Mountains. Interstate 40 is highly recommended for its scenery between Interstate 81 and Interstate 26 at Asheville (an 80 mile drive). Photo taken by Jeffrey Napier (1/02).
Replaced signage on the sign bridge at the Interstate 40 east/Interstate 81 northbound split. The next Interstate junction Interstate 81 encounters is that of Interstate 181/Future Interstate 26, some 57 miles to the north. Interstate 26 is also the next Interstate junction for Interstate 40 eastbound. Vidcap taken 05/29/95.
Next Three Interstate Junctions for Interstate 40 east
Interstate 26/
Interstate 240
80 miles at west Asheville, NC
Interstate 240 87 miles at east Ashville, NC
Interstate 77 186 miles at Statesville, NC
Northern Terminus - Canadian International Border - Alexandria Bay, New York
Perspective from Interstate 81 north
Interstate 81 sees the last U.S. exit at Island Road/De Wolf Point/Exit 52 before crossing the Thousand Islands into Ontario, Canada. A variety of state parks are situated on the islands that reside within the Saint Lawrence River valley and are accessible from this interchange. Photo taken by Douglas Kerr (11/08/02).
Continuing beyond Exit 52, Interstate 81 reduces to two lanes for this span across the Saint Lawrence River into Ontario, Canada. This photo looks at the span from a nearby frontage road on the Thousand Islands. Photo taken by Douglas Kerr (11/08/02).
Further north, the Wellesley Bridge bridges the Saint Lawrence north channel into mainland Ontario. Traffic counts are relatively low on this span, thus two lanes are sufficient for the crossing as it stands. Soon after entering the mainland, traffic encounters the Ontario 401 freeway between Kingston and Cornwall. Photos taken by Douglas Kerr (11/08/02).
Perspective from Interstate 81 south
After crossing the two lane Saint Lawrence River bridge, the first Interstate 81 southbound shield greets motorists. This shield is posted just after the freeway widens to four lanes. The frontage road to the right connects with Exit 52 ahead. Photo taken by Douglas Kerr (11/08/02).
Interstate 81 southbound at Exit 51/Islands Road, the first U.S. interchange of the freeway. The towers in the background consist of the Interstate 81 1,000 Islands Bridge. Otherwise Exit 50N/S for New York 12, the first mainland New York state interchange, is one mile to the south. Photo taken by Douglas Kerr (11/08/02).
Next Three Interstate Junctions for Interstate 81 south
Interstate 481 87 miles at North Syracuse, NY
Interstate 90 92 miles at Syracuse, NY
Interstate 690 95 miles at downtown Syracuse, NY
Perspective from New York 12
Interstate 81 and New York 12 overhead on New York 12 south in Alexandria Bay. This is just south of the 1000 Islands Bridge that connects Interstate 81 with Wellesley Island and Canada. Traffic proceeded southward through the Interstate 81 interchange on New York 12 will reach Clayton (pop. 1821) in seven miles. Photo taken by Douglas Kerr (10/00).
New York 12 northbound at the Exit 50N/S interchange of Interstate 81. The northbound signage uses 1000 Islands Bridge in lieu of Interstate 81 while southbound signage shows the control city of Watertown, a city of 26,705, distanced 23 miles to the south. Photo taken by Douglas Kerr (11/08/02).
Perspective from Ontario 401 east
Now traveling east on Ontario 401, this sign advises that Ontario 137 leads south to the Thousand Islands Bridge, which connects to Interstate 81 in New York. Photo taken by Jeff Morrison (06/27/07).
Ontario 401 eastbound meets Ontario 137, which is the connector to Interstate 81 via Hill Island. Ontario 401 itself is a lengthy freeway between Windsor near Detroit, Michigan and Quebec near Cornwall, Ontario. Photos taken by Jeff Morrison (06/27/07) and Douglas Kerr (11/08/02).
Perspective from Ontario 401 west
Omitted from the sign bridges for the Interstate 81 exit, the interchange is signed as Exit 661. This photo looks at the one kilometer guide sign on Ontario 401 westbound for the Hill Island interchange. The United States border is approximately two kilometers to the south. Photo taken by Douglas Kerr (11/08/02).
Ontario 401 westbound at the Interstate 81/Bridge to U.S.A. ramp (Exit 661). The westbound control city for Ontario 401 is that of the city of Kingston. The city of 114,195 is 30 kilometers to the west. 235 kilometers beyond Kingston is the capital city of Ontario Province, Toronto. Photo taken by Douglas Kerr (11/08/02).


  1. "VDOT criticizes 2 consortiums' plans to widen I-81." Roanoke Times, November 15, 2003.
  2. Pennsylvania Highways: Interstate 81.
  3. MDRoads: I-81.
  4. Interstate 81 in Virginia (RoadstotheFuture).
  5. Interstate 81 in New York @
  6. Interstate system route numbering web site, Stephen Summers.
  7. "Research panel predicts state road fund shortage." Charleston Gazette (WV), June 22, 2006.

Page Updated June 24, 2015.