Interstate 81
   HOME

TheInfoList



OR:

Interstate 81 (I-81) is a north–south (physically northeast–southwest)
Interstate Highway The Dwight D. Eisenhower National System of Interstate and Defense Highways, commonly known as the Interstate Highway System, is a network of controlled-access highways that forms part of the National Highway System in the United States. Th ...
in the eastern part of the
United States The United States of America (U.S.A. or USA), commonly known as the United States (U.S. or US) or America, is a country primarily located in North America. It consists of 50 states, a federal district, five major unincorporated territorie ...
. Its southern terminus is at
I-40 Interstate 40 (I-40) is a major east–west Interstate Highway running through the south-central portion of the United States. At a length of , it is the third-longest Interstate Highway in the country, after I-90 and I-80. From west to ea ...
in Dandridge,
Tennessee Tennessee ( , ), officially the State of Tennessee, is a landlocked state in the Southeastern region of the United States. Tennessee is the 36th-largest by area and the 15th-most populous of the 50 states. It is bordered by Kentucky to th ...
; its northern terminus is on
Wellesley Island Wellesley Island in Jefferson County, New York, United States is partially in the Town of Orleans and partially in the Town of Alexandria. History The island was named Wells Island but during his 1815 survey of the US-Canada border renamed by ...
, New York at the
Canadian border Canadians (french: Canadiens) are people identified with the country of Canada. This connection may be residential, legal, historical or cultural. For most Canadians, many (or all) of these connections exist and are collectively the source of ...
, where the
Thousand Islands Bridge The Thousand Islands International Bridge (french: Pont des Mille-îles) is an American-maintained international bridge system over the Saint Lawrence River connecting northern New York in the United States with southeastern Ontario in Canada. Co ...
connects it to Highway 137 and ultimately to
Highway 401 King's Highway 401, commonly referred to as Highway 401 and also known by its official name as the Macdonald–Cartier Freeway or colloquially referred to as the four-oh-one, is a controlled-access 400-series highway in the Canadian provin ...
, the main
Ontario Ontario ( ; ) is one of the thirteen provinces and territories of Canada.Ontario is located in the geographic eastern half of Canada, but it has historically and politically been considered to be part of Central Canada. Located in Central Ca ...
freeway connecting
Detroit Detroit ( , ; , ) is the largest city in the U.S. state of Michigan. It is also the largest U.S. city on the United States–Canada border, and the seat of government of Wayne County. The City of Detroit had a population of 639,111 at th ...
via
Toronto Toronto ( ; or ) is the capital city of the Canadian province of Ontario. With a recorded population of 2,794,356 in 2021, it is the most populous city in Canada and the fourth most populous city in North America. The city is the ancho ...
to
Montreal Montreal ( ; officially Montréal, ) is the List of the largest municipalities in Canada by population, second-most populous city in Canada and List of towns in Quebec, most populous city in the Provinces and territories of Canada, Canadian ...
. The major metropolitan areas along the route of I-81 include the Tri-Cities of Tennessee; Roanoke in
Virginia Virginia, officially the Commonwealth of Virginia, is a state in the Mid-Atlantic and Southeastern regions of the United States, between the Atlantic Coast and the Appalachian Mountains. The geography and climate of the Commonwealth ar ...
;
Harrisburg Harrisburg is the capital city of the Pennsylvania, Commonwealth of Pennsylvania, United States, and the county seat of Dauphin County, Pennsylvania, Dauphin County. With a population of 50,135 as of the 2021 census, Harrisburg is the List of c ...
and the
Wyoming Valley The Wyoming Valley is a historic industrialized region of Northeastern Pennsylvania. The region is historically notable for its influence in helping fuel the American Industrial Revolution with its many anthracite coal-mines. As a metropolitan are ...
in
Pennsylvania Pennsylvania (; ( Pennsylvania Dutch: )), officially the Commonwealth of Pennsylvania, is a state spanning the Mid-Atlantic, Northeastern, Appalachian, and Great Lakes regions of the United States. It borders Delaware to its southeast, ...
; and Syracuse in New York. I-81 largely traces the paths created down the length of the
Appalachian Mountains The Appalachian Mountains, often called the Appalachians, (french: Appalaches), are a system of mountains in eastern to northeastern North America. The Appalachians first formed roughly 480 million years ago during the Ordovician Period. They ...
through the
Great Appalachian Valley The Great Appalachian Valley, also called The Great Valley or Great Valley Region, is one of the major landform features of eastern North America. It is a gigantic trough—a chain of valley lowlands—and the central feature of the Appalachian M ...
by migrating animals,
indigenous peoples Indigenous peoples are culturally distinct ethnic groups whose members are directly descended from the earliest known inhabitants of a particular geographic region and, to some extent, maintain the language and culture of those original people ...
, and early settlers. It also follows a major corridor for troop movements during the
Civil War A civil war or intrastate war is a war between organized groups within the same state (or country). The aim of one side may be to take control of the country or a region, to achieve independence for a region, or to change government policies ...
. These trails and roadways gradually evolved into US Route 11 (US 11); I-81 parallels much of the older US 11. Being mostly rural in nature, I-81 is heavily used as a trucking corridor and is often used as a bypass of busier and more congested Interstates to the east such as
I-95 Interstate 95 (I-95) is the main north–south Interstate Highway on the East Coast of the United States, running from US Route 1 (US 1) in Miami, Florida, to the Houlton–Woodstock Border Crossing between Maine and the Canadia ...
; for this reason, it is also used heavily by
drug A drug is any chemical substance that causes a change in an organism's physiology or psychology when consumed. Drugs are typically distinguished from food and substances that provide nutritional support. Consumption of drugs can be via insuffla ...
and
human trafficker Human trafficking is the trade of humans for the purpose of forced labour, sexual slavery, or commercial sexual exploitation for the trafficker or others. This may encompass providing a spouse in the context of forced marriage, or the extracti ...
s, as it is less monitored by
law enforcement Law enforcement is the activity of some members of government who act in an organized manner to enforce the law by discovering, deterring, rehabilitating, or punishing people who violate the rules and norms governing that society. The term en ...
than I-95. This led to the
Federal Bureau of Investigation The Federal Bureau of Investigation (FBI) is the domestic intelligence and security service of the United States and its principal federal law enforcement agency. Operating under the jurisdiction of the United States Department of Justice, ...
(FBI) forming a taskforce to combat the issue in 2017. The I-81 Corridor Coalition, a six-state coalition, was organized to handle issues along I-81, such as truck traffic and air pollution; the commission meets annually. I-81 is part of the fastest route between the
capital Capital may refer to: Common uses * Capital city, a municipality of primary status ** List of national capital cities * Capital letter, an upper-case letter Economics and social sciences * Capital (economics), the durable produced goods used f ...
of the US (
Washington, DC ) , image_skyline = , image_caption = Clockwise from top left: the Washington Monument and Lincoln Memorial on the National Mall, United States Capitol, Logan Circle, Jefferson Memorial, White House, Adams Morgan ...
) and the capital of
Canada Canada is a country in North America. Its ten provinces and three territories extend from the Atlantic Ocean to the Pacific Ocean and northward into the Arctic Ocean, covering over , making it the world's second-largest country by tot ...
(
Ottawa Ottawa (, ; Canadian French: ) is the capital city of Canada. It is located at the confluence of the Ottawa River and the Rideau River in the southern portion of the province of Ontario. Ottawa borders Gatineau, Quebec, and forms the core ...
) and
Mexico Mexico (Spanish: México), officially the United Mexican States, is a country in the southern portion of North America. It is bordered to the north by the United States; to the south and west by the Pacific Ocean; to the southeast by Guatema ...
(
Mexico City Mexico City ( es, link=no, Ciudad de México, ; abbr.: CDMX; Nahuatl: ''Altepetl Mexico'') is the capital and largest city of Mexico, and the most populous city in North America. One of the world's alpha cities, it is located in the Valley o ...
).


Route description

I-81 is part of the National Highway System, a network of highways that are considered essential to the country's economy, defense, and mobility by the
Federal Highway Administration The Federal Highway Administration (FHWA) is a division of the United States Department of Transportation that specializes in highway transportation. The agency's major activities are grouped into two programs, the Federal-aid Highway Program a ...
(FHWA). , - , TN , , , - , VA , , , - , WV , , , - , MD , , , - , PA , , , - , NY , , , - , Total , ,


Tennessee

I-81 begins in Tennessee at
I-40 Interstate 40 (I-40) is a major east–west Interstate Highway running through the south-central portion of the United States. At a length of , it is the third-longest Interstate Highway in the country, after I-90 and I-80. From west to ea ...
in Dandridge, a route that connects to
Knoxville Knoxville is a city in and the county seat of Knox County in the U.S. state of Tennessee. As of the 2020 United States census, Knoxville's population was 190,740, making it the largest city in the East Tennessee Grand Division and the state's ...
to the west and
Asheville Asheville ( ) is a city in, and the county seat of, Buncombe County, North Carolina. Located at the confluence of the French Broad and Swannanoa rivers, it is the largest city in Western North Carolina, and the state's 11th-most populous ci ...
to the east. I-81 meets I-26 and US 23, which go to Kingsport and Johnson City. At milemarker 75, I-81 leaves Tennessee and enters Virginia.


Virginia

I-81 in Virginia is largely a rural route with brief concurrencies with
I-77 Interstate 77 (I-77) is a north–south Interstate Highway in the eastern United States. It traverses diverse terrain, from the mountainous state of West Virginia to the rolling farmlands of North Carolina and Ohio. It largely supplants the ...
and
I-64 Interstate 64 (I-64) is an east–west Interstate Highway in the Eastern United States. Its western terminus is at I-70, U.S. Route 40 (US 40), and US 61 in Wentzville, Missouri. Its eastern terminus is at an interchang ...
. The route parallels the Appalachian Mountains for much of its route through Tennessee and Virginia, serving such cities as the
twin cities Twin cities are a special case of two neighboring cities or urban centres that grow into a single conurbation – or narrowly separated urban areas – over time. There are no formal criteria, but twin cities are generally comparable in sta ...
of Bristol,
Tennessee Tennessee ( , ), officially the State of Tennessee, is a landlocked state in the Southeastern region of the United States. Tennessee is the 36th-largest by area and the 15th-most populous of the 50 states. It is bordered by Kentucky to th ...
and
Virginia Virginia, officially the Commonwealth of Virginia, is a state in the Mid-Atlantic and Southeastern regions of the United States, between the Atlantic Coast and the Appalachian Mountains. The geography and climate of the Commonwealth ar ...
;
Wytheville Wytheville is a town in, and the county seat of, Wythe County, in southwestern Virginia, United States. It is named after George Wythe, a signer of the United States Declaration of Independence, and mentor to Thomas Jefferson. Wytheville's populat ...
; Roanoke; Christiansburg; Lexington; Staunton; Harrisonburg; and
Winchester Winchester is a City status in the United Kingdom, cathedral city in Hampshire, England. The city lies at the heart of the wider City of Winchester, a local government Districts of England, district, at the western end of the South Downs Nation ...
. In Harrisonburg, I-81 cuts through
James Madison University James Madison University (JMU, Madison, or James Madison) is a public research university in Harrisonburg, Virginia. Founded in 1908 as the State Normal and Industrial School for Women at Harrisonburg, the institution was renamed Madison Coll ...
. It parallels its older counterpart, US 11, for its entire length in Virginia.


West Virginia

I-81 briefly enters the
Eastern Panhandle of West Virginia The Eastern Panhandle is the eastern of the two panhandles in the U.S. state of West Virginia; the other is the Northern Panhandle. It is a small stretch of territory in the northeast of the state, bordering Maryland and Virginia. Some sources ...
for about , serving the city of Martinsburg. The entire routing is in Berkeley County and serves the
Eastern WV Regional Airport Eastern West Virginia Regional Airport , also known as Shepherd Field, is a civilian-owned, public use airport located four  nautical miles (5  mi, 7  km) south of the central business district of Martinsburg, a city in Berkeley ...
. The
West Virginia West Virginia is a state in the Appalachian, Mid-Atlantic and Southeastern regions of the United States.The Census Bureau and the Association of American Geographers classify West Virginia as part of the Southern United States while the Bur ...
segment was completed in 1966 and there have been no realignments since.


Maryland

In
Maryland Maryland ( ) is a state in the Mid-Atlantic region of the United States. It shares borders with Virginia, West Virginia, and the District of Columbia to its south and west; Pennsylvania to its north; and Delaware and the Atlantic Ocean to ...
, the Interstate Highway runs from the
West Virginia West Virginia is a state in the Appalachian, Mid-Atlantic and Southeastern regions of the United States.The Census Bureau and the Association of American Geographers classify West Virginia as part of the Southern United States while the Bur ...
state line at the
Potomac River The Potomac River () drains the Mid-Atlantic United States, flowing from the Potomac Highlands into Chesapeake Bay. It is long,U.S. Geological Survey. National Hydrography Dataset high-resolution flowline dataThe National Map. Retrieved Augus ...
in Williamsport north to the
Pennsylvania Pennsylvania (; ( Pennsylvania Dutch: )), officially the Commonwealth of Pennsylvania, is a state spanning the Mid-Atlantic, Northeastern, Appalachian, and Great Lakes regions of the United States. It borders Delaware to its southeast, ...
state line near Maugansville. I-81 is the primary north–south Interstate Highway in Washington County, connecting Hagerstown with
Chambersburg Chambersburg is a borough in and the county seat of Franklin County, in the South Central region of Pennsylvania, United States. It is in the Cumberland Valley, which is part of the Great Appalachian Valley, and north of Maryland and the Mas ...
and
Harrisburg Harrisburg is the capital city of the Pennsylvania, Commonwealth of Pennsylvania, United States, and the county seat of Dauphin County, Pennsylvania, Dauphin County. With a population of 50,135 as of the 2021 census, Harrisburg is the List of c ...
to the north and Martinsburg,
Winchester Winchester is a City status in the United Kingdom, cathedral city in Hampshire, England. The city lies at the heart of the wider City of Winchester, a local government Districts of England, district, at the western end of the South Downs Nation ...
, and Roanoke to the south. It is the shortest mainline Interstate in Maryland and contains the shortest portion of I-81 of all six states through which the Interstate highway passes. The Interstate was dedicated as Maryland Veterans Memorial Highway in 1987. I-81 passes through the state of Maryland at one of its narrowest points, the "Hub City" of Hagerstown where it intersects with a large number of other routes, most notably
I-70 Interstate 70 (I-70) is a major east–west Interstate Highway in the United States that runs from I-15 near Cove Fort, Utah, to a park and ride lot just east of I-695 in Baltimore, Maryland, and is the fifth-longest Interstate in the c ...
.
Hagerstown Regional Airport Hagerstown Regional Airport ( Richard A. Henson Field) is in Washington County, Maryland, five miles north of Hagerstown, Maryland and a half mile (800 m) from the Maryland/Pennsylvania border. The airport is off Interstate 81 at exit 10 and ...
is served by this Interstate Highway.


Pennsylvania

I-81 forms a major north–south corridor through the state of Pennsylvania, serving the boroughs of
Chambersburg Chambersburg is a borough in and the county seat of Franklin County, in the South Central region of Pennsylvania, United States. It is in the Cumberland Valley, which is part of the Great Appalachian Valley, and north of Maryland and the Mas ...
and
Carlisle Carlisle ( , ; from xcb, Caer Luel) is a city that lies within the Northern England, Northern English county of Cumbria, south of the Anglo-Scottish border, Scottish border at the confluence of the rivers River Eden, Cumbria, Eden, River C ...
, where it meets the
Pennsylvania Turnpike The Pennsylvania Turnpike (Penna Turnpike or PA Turnpike) is a toll highway operated by the Pennsylvania Turnpike Commission (PTC) in the U.S. state of Pennsylvania. A controlled-access highway, it runs for across the state. The turnpike's we ...
(
I-76 Interstate 76 may refer to: Interstate Highways in the United States * Interstate 76 (Colorado–Nebraska) * Interstate 76 (Ohio–New Jersey), running through Pennsylvania Video gaming * ''Interstate '76 ''Interstate '76'' is a vehicular ...
) but does not directly interchange with it (motorists must use US 11 to connect). Around the state capital of
Harrisburg Harrisburg is the capital city of the Pennsylvania, Commonwealth of Pennsylvania, United States, and the county seat of Dauphin County, Pennsylvania, Dauphin County. With a population of 50,135 as of the 2021 census, Harrisburg is the List of c ...
, the route forms the northern section of Pennsylvania's
Capital Beltway The Capital Beltway is a Interstate Highway in the Washington metropolitan area that surrounds Washington, D.C., the capital of the United States, and its inner suburbs in adjacent Maryland and Virginia. It is the basis of the phrase " inside ...
. The route then travels northeast toward the
Wyoming Valley The Wyoming Valley is a historic industrialized region of Northeastern Pennsylvania. The region is historically notable for its influence in helping fuel the American Industrial Revolution with its many anthracite coal-mines. As a metropolitan are ...
, where it serves the cities of
Wilkes-Barre Wilkes-Barre ( or ) is a city in the U.S. state of Pennsylvania and the county seat of Luzerne County. Located at the center of the Wyoming Valley in Northeastern Pennsylvania, it had a population of 44,328 in the 2020 census. It is the secon ...
and
Scranton Scranton is a city in the Commonwealth (U.S. state), Commonwealth of Pennsylvania, United States, and the county seat of Lackawanna County, Pennsylvania, Lackawanna County. With a population of 76,328 as of the 2020 United States census, 2020 U ...
, then heads north through the
Endless Mountains The Endless Mountains are a geographical, geological, and cultural region in Northeastern Pennsylvania. The Endless Mountains region includes Bradford, Sullivan, Susquehanna, and Wyoming counties. The highest peak in the region is the North Kn ...
region toward the state line.


New York

In New York, I-81 crosses the Pennsylvania state line southeast of
Binghamton Binghamton () is a city in the U.S. state of New York, and serves as the county seat of Broome County. Surrounded by rolling hills, it lies in the state's Southern Tier region near the Pennsylvania border, in a bowl-shaped valley at the conflue ...
. The freeway runs north–south through
Central New York Central New York is the central region of New York State, including the following counties and cities: With a population of about 773,606 (2009) and an area of , the region includes the Syracuse metropolitan area. Definitions The New York ...
, serving the cities of Binghamton, Syracuse, and
Watertown Watertown may refer to: Places in China In China, a water town is a type of ancient scenic town known for its waterways. Places in the United States *Watertown, Connecticut, a New England town **Watertown (CDP), Connecticut, the central village ...
. It passes through the
Thousand Islands The Thousand Islands (french: Mille-Îles) constitute a North American archipelago of 1,864 islands that straddles the Canada–US border in the Saint Lawrence River as it emerges from the northeast corner of Lake Ontario. They stretch for abo ...
in its final miles and crosses two bridges, both part of the series of bridges known as the
Thousand Islands Bridge The Thousand Islands International Bridge (french: Pont des Mille-îles) is an American-maintained international bridge system over the Saint Lawrence River connecting northern New York in the United States with southeastern Ontario in Canada. Co ...
. South of Watertown, I-81 closely parallels US 11, the main north–south highway in Central New York prior to the construction of I-81. At Watertown, US 11 turns northeastward to head across New York's North Country while I-81 continues on a generally northward track to the Canadian border. From there, the road continues into the province of
Ontario Ontario ( ; ) is one of the thirteen provinces and territories of Canada.Ontario is located in the geographic eastern half of Canada, but it has historically and politically been considered to be part of Central Canada. Located in Central Ca ...
as Highway 137, a short route leading north to the nearby
Highway 401 King's Highway 401, commonly referred to as Highway 401 and also known by its official name as the Macdonald–Cartier Freeway or colloquially referred to as the four-oh-one, is a controlled-access 400-series highway in the Canadian provin ...
.


History

I-81 roughly parallels the
Great Indian Warpath The Great Indian Warpath (GIW)—also known as the Great Indian War and Trading Path, or the Seneca Trail—was that part of the network of trails in eastern North America developed and used by Native Americans which ran through the Great Appala ...
, an old Indian trail that connected New York to the
Piedmont it, Piemontese , population_note = , population_blank1_title = , population_blank1 = , demographics_type1 = , demographics1_footnotes = , demographics1_title1 = , demographics1_info1 = , demographics1_title2 ...
via Virginia and West Virginia. A series of roads linking Virginia to Maryland through Martinsburg were present on maps as early as 1873. New York was originally served by
New York State Route 2 New York State Route 2 (NY 2) is a state highway in the Capital District of New York in the United States. It extends for from an interchange with Interstate 87 (I-87) and NY 7 in the town of Colonie to the Massachusetts ...
(NY 2), a road built in 1924; NY 2 was replaced by US 11 in 1927. A highway that largely followed the path of US 11 was built and became known as the Penn-Can Highway. On August 14, 1957 the highway was redesigned as I-81. In New York, the first segments of I-81 were begun in 1954. In Maryland, the Interstate was begun with the Hagerstown Bypass in the mid-1950s. After several bouts of expansion, the freeway was completed from US 40 (now
Maryland Route 144 Maryland Route 144 (MD 144) is a collection of state highways in the U.S. state of Maryland. These highways are sections of old alignment of U.S. Route 40 (US 40) between Cumberland and Baltimore. Along with US 40 Scenic, US 40 Alternate ...
D 144 to the Pennsylvania state line in 1958 and marked as I-81 in 1959. Bidding on contracts in West Virginia opened in July 1958. In Virginia, the first Interstate hearing was held in February 1957. At the end of 1957, construction began on a stretch near
Buchanan, Virginia Buchanan ( ) is a town in Botetourt County, Virginia, United States. The population was 1,196 at the 2020 census. It is part of the Roanoke Metropolitan Statistical Area. It was the western terminus of the James River and Kanawha Canal when cons ...
. A section of the Interstate opened in 1959. A stretch in Harrisonburg was opened as well. By late 1963, in Virginia were open. The first statewide segment to be completed was that of West Virginia, which was finished in 1966. The section opened on October 19, 1966. In western Maryland, various parts of I-81 were built in the early 1960s, and the remainder of the highway south to the Potomac River was under construction by 1965 and opened in 1966. Since then, I-81 in Maryland has remained largely unchanged. In Tennessee by 1965, of the of Interstate Highways were completed. Construction was expected to be finished in 1969, but a large portion of the work would not be completed until 1974, and most of the road was open by December 1974. The final major segment of the Interstate in the north to be built was a section in New York, opened in October 1968. That same year, work in Pennsylvania was completed. The road would not be completely built in Tennessee until August 1975. Construction on parts in Virginia dragged on until it was finished in July 1987. The segment in New York cost $270 million (equivalent to $ in ) to build.


Major intersections

;Tennessee * near Dandridge, northeast of
Knoxville Knoxville is a city in and the county seat of Knox County in the U.S. state of Tennessee. As of the 2020 United States census, Knoxville's population was 190,740, making it the largest city in the East Tennessee Grand Division and the state's ...
* between the Tri-Cities ;Virginia * in
Bristol Bristol () is a city, ceremonial county and unitary authority in England. Situated on the River Avon, it is bordered by the ceremonial counties of Gloucestershire to the north and Somerset to the south. Bristol is the most populous city in ...
* in
Wytheville Wytheville is a town in, and the county seat of, Wythe County, in southwestern Virginia, United States. It is named after George Wythe, a signer of the United States Declaration of Independence, and mentor to Thomas Jefferson. Wytheville's populat ...
; they stay joined for about . * in Roanoke * in Lexington; they stay joined through Staunton. * in Harrisonburg * in Middletown ;Maryland * in Hagerstown * in Hagerstown ;Pennsylvania * in Middlesex Township (near
Carlisle Carlisle ( , ; from xcb, Caer Luel) is a city that lies within the Northern England, Northern English county of Cumbria, south of the Anglo-Scottish border, Scottish border at the confluence of the rivers River Eden, Cumbria, Eden, River C ...
) * in Enola * in
Harrisburg Harrisburg is the capital city of the Pennsylvania, Commonwealth of Pennsylvania, United States, and the county seat of Dauphin County, Pennsylvania, Dauphin County. With a population of 50,135 as of the 2021 census, Harrisburg is the List of c ...
. I-81/US 322 stays joined throughout Harrisburg. * in Harrisburg * near
Jonestown The Peoples Temple Agricultural Project, better known by its informal name "Jonestown", was a remote settlement in Guyana established by the Peoples Temple, a U.S.–based cult under the leadership of Jim Jones. Jonestown became internationall ...
* near
Hazleton Hazleton may refer to: Places * Hazleton, British Columbia, Canada * Hazleton, Gloucestershire, a village in Gloucestershire, England ** Hazleton long barrows, Neolithic burial mounds at Hazleton, Gloucestershire, England ** Hazleton Abbey, a medi ...
* in
Dupont DuPont de Nemours, Inc., commonly shortened to DuPont, is an American multinational chemical company first formed in 1802 by French-American chemist and industrialist Éleuthère Irénée du Pont de Nemours. The company played a major role in ...
(near Pittston) * in
Dunmore Dunmore from the ga, Dún Mór, link=no or gd, Dùn Mòr, link=no, meaning "great fort", may refer to: People * Dunmore (surname) * Earl of Dunmore, a title in the Peerage of Scotland, includes a list of earls * Countess of Dunmore (disambiguat ...
(near
Scranton Scranton is a city in the Commonwealth (U.S. state), Commonwealth of Pennsylvania, United States, and the county seat of Lackawanna County, Pennsylvania, Lackawanna County. With a population of 76,328 as of the 2020 United States census, 2020 U ...
) * in Clarks Summit ;New York * in
Binghamton Binghamton () is a city in the U.S. state of New York, and serves as the county seat of Broome County. Surrounded by rolling hills, it lies in the state's Southern Tier region near the Pennsylvania border, in a bowl-shaped valley at the conflue ...
* in Binghamton * in Syracuse * in downtown Syracuse * in North Syracuse * in
Watertown Watertown may refer to: Places in China In China, a water town is a type of ancient scenic town known for its waterways. Places in the United States *Watertown, Connecticut, a New England town **Watertown (CDP), Connecticut, the central village ...
* ; freeway ends at Canada–US border (
Thousand Islands Bridge The Thousand Islands International Bridge (french: Pont des Mille-îles) is an American-maintained international bridge system over the Saint Lawrence River connecting northern New York in the United States with southeastern Ontario in Canada. Co ...
)


Auxiliary routes

I-81 has six related,
auxiliary Interstate Highway Auxiliary Interstate Highways (also called three-digit Interstate Highways) are a supplemental subset of the freeways within the Interstate Highway System of the United States. Auxiliary routes are generally classified as spur routes, which con ...
s that connect the main freeway to downtowns and other cities. I-381 runs , connecting
Bristol, Virginia Bristol is an independent city in the Commonwealth of Virginia. As of the 2020 census, the population was 17,219. It is the twin city of Bristol, Tennessee, just across the state line, which runs down the middle of its main street, State S ...
, to I-81. I-581 is a spur that connects
Roanoke, Virginia Roanoke ( ) is an independent city in the U.S. state of Virginia. At the 2020 census, the population was 100,011, making it the 8th most populous city in the Commonwealth of Virginia and the largest city in Virginia west of Richmond. It is lo ...
, to I-81. It is proposed to be overtaken by
I-73 Interstate 73 (I-73) is a north–south Interstate Highway, located within the US state of North Carolina. Currently, there is one continuous section of I-73, totaling , first traversing the U.S. Route 220 (US 220) freeway from ...
.
Pennsylvania Route 581 The Capital Beltway is a beltway surrounding Harrisburg, Pennsylvania, in the United States. It is co-designated as Interstate 81 (I-81), I-83, U.S. Route 11 (US 11), US 322, and Pennsylvania Route 581 (PA 581) ...
(PA 581) connects
Harrisburg, Pennsylvania Harrisburg is the capital city of the Commonwealth of Pennsylvania, United States, and the county seat of Dauphin County. With a population of 50,135 as of the 2021 census, Harrisburg is the 9th largest city and 15th largest municipality in Pe ...
, to I-81. It runs . I-481 serves as an eastern bypass of
Syracuse, New York Syracuse ( ) is a City (New York), city in and the county seat of Onondaga County, New York, Onondaga County, New York, United States. It is the fifth-most populous city in the state of New York following New York City, Buffalo, New York, Buffa ...
. I-781 extends for , that connects
Fort Drum, New York Fort Drum is a U.S. Army military reservation and a census-designated place (CDP) in Jefferson County, on the northern border of New York, United States. The population of the CDP portion of the base was 12,955 at the 2010 census. It is home ...
, to the Interstate. NY 281 is a north–south
state highway A state highway, state road, or state route (and the equivalent provincial highway, provincial road, or provincial route) is usually a road that is either ''numbered'' or ''maintained'' by a sub-national state or province. A road numbered by a ...
in
Central New York Central New York is the central region of New York State, including the following counties and cities: With a population of about 773,606 (2009) and an area of , the region includes the Syracuse metropolitan area. Definitions The New York ...
in the US that extends for across Cortland and
Onondaga Onondaga may refer to: Native American/First Nations * Onondaga people, a Native American/First Nations people and one of the five founding nations of the Iroquois League * Onondaga (village), Onondaga settlement and traditional Iroquois capita ...
counties, roughly paralleling I-81 and connecting at both ends. I-181 was a offshoot of I-81, linking to
Kingsport, Tennessee Kingsport is a city in Sullivan and Hawkins counties in the U.S. state of Tennessee. As of the 2020 census, its population was 55,442. Lying along the Holston River, Kingsport is commonly included in what is known as the Mountain Empire, w ...
. It was decommissioned in August 2005 when I-26 took over I-181's entire length. I-281 was replaced in January 1970 by I-481. I-81E was replaced by the current
I-380 Interstate 380 may refer to: * Interstate 380 (California) Interstate 380 (I-380) is a short east–west auxiliary Interstate Highway in the San Francisco Bay Area of Northern California, connecting I-280 in San Bruno to US Route& ...
.


References


External links

*
Thousand Islands Bridge System
showing the bridges and connections at the northern terminus

a Federal Highway Administration report. {{Authority control 81