Interstate 79

Interstate 79
State	PA/WV/OH
Type	Interstate
Route	79
Length mi	343
Established	1958
Direction a	south
Terminus a	near Charleston, Charleston, West Virginia
Junction	near Clarksburg, Clarksburg, West Virginia; near Morgantown, Morgantown, West Virginia; near Washington, Washington, Pennsylvania; near Pittsburgh, Pittsburgh, Pennsylvania; near Erie, Erie, Pennsylvania
Direction b	north
Terminus b	near Erie, Erie, Pennsylvania
States	West Virginia; Pennsylvania

Interstate 79

Interstate 79 is a major north–south limited-access highway connecting Charleston, West Virginia, the northern Ohio River corridor, and the Erie, Pennsylvania region. The route links metropolitan areas including Pittsburgh, Morgantown, West Virginia, and smaller regional centers such as Uniontown, Pennsylvania and Clarksburg, West Virginia. Commissioned during the Federal-Aid Highway Act of 1956 era, the roadway serves freight, commuter, and regional travel across Appalachian and Lake Erie watershed landscapes.

Route description

The corridor begins in the vicinity of Charleston, West Virginia and proceeds northward through the Allegheny Plateau landscape, traversing counties such as Kanawha County, West Virginia and Harrison County, West Virginia. Approaching Clarksburg, West Virginia the route intersects with regional arterials including U.S. Route 50 (West Virginia) and U.S. Route 19, providing access to communities like Bridgeport, West Virginia and Fairmont, West Virginia. North of Morgantown, West Virginia the highway skirts the Monongahela River basin and meets major connectors such as Interstate 68 near the Pennsylvania turnpike corridor and shifting terrain toward Washington County, Pennsylvania. As it approaches the Pittsburgh metropolitan area the expressway passes near suburbs like Findlay Township, Pennsylvania and interchanges with the Pennsylvania Turnpike (I-76) and other radial freeways serving Downtown Pittsburgh. North of Allegheny County, Pennsylvania the alignment continues into rural sections of Armstrong County, Pennsylvania and Mercer County, Pennsylvania, ultimately reaching the Erie, Pennsylvania approach where it interfaces with routes serving the Port of Erie and the Lake Erie shoreline.

History

Planning for the route originated during the Dwight D. Eisenhower administration's interstate program led by the Bureau of Public Roads. Early routing proposals considered alignments following historic corridors such as U.S. Route 19 and regional turnpikes linking Pittsburgh with the Ohio Valley. Construction milestones included completion of key segments near Morgantown in the 1960s and urban connector work around Pittsburgh in subsequent decades. Major construction projects tied to the corridor intersected with initiatives by state departments such as the Pennsylvania Department of Transportation and the West Virginia Department of Transportation. Economic and environmental reviews involved stakeholders including the U.S. Army Corps of Engineers for watershed impacts and regional planning agencies like the North Central Pennsylvania Regional Planning and Development Commission. Over time, upgrades addressed increasing freight movements tied to the Norfolk Southern Railway and CSX Transportation intermodal flows, while local campaigns in communities such as Uniontown and Greene County, Pennsylvania influenced interchange design and access.

Exit list

Exit numbering follows standard interstate conventions, with mile-based markers administered by the Pennsylvania Department of Transportation and the West Virginia Division of Highways. Major interchanges include connections with Interstate 64 near the southern terminus area, a junction with U.S. Route 50 (West Virginia) near central West Virginia cities, and interchange complexes with Interstate 376 and U.S. Route 19 serving the Pittsburgh International Airport region. Northbound travelers encounter exits serving Butler, Pennsylvania, Slippery Rock, Pennsylvania, and access to the Penn State Erie, The Behrend College area before the corridor meets routes into Erie County, Pennsylvania and access to the Interstate 90 corridor. Local numbering and auxiliary ramps provide connections to municipal roads administered by county governments such as Monongalia County, West Virginia and Lawrence County, Pennsylvania.

Traffic and tolling

Traffic volumes vary from high-volume commuter and freight sections near Pittsburgh and Morgantown to lower-volume rural stretches in Harrison County, West Virginia and northern Pennsylvania. Peak congestion occurs at major urban interchanges linked to the Pittsburgh International Airport and during seasonal travel to recreational destinations along the Allegheny National Forest periphery. Tolling policy on contiguous corridors is influenced by regional tolled facilities such as the Pennsylvania Turnpike and the West Virginia Turnpike; however, the primary corridor itself operates as a non-tolled interstate under maintenance by respective state agencies. Freight throughput on the corridor is coordinated with modal partners including Port of Pittsburgh Commission interests, reflecting commodity flows tied to the Appalachian Regional Commission economic zone.

Future projects and improvements

Planned improvements include interchange reconstructions, bridge rehabilitations, and capacity enhancements prioritized by state transportation improvement programs administered by the Federal Highway Administration and state departments. Projects under study have considered managed lanes, safety upgrades addressing winter operations coordinated with the National Weather Service, and access improvements to economic development sites promoted by entities such as the Allegheny Conference on Community Development and regional economic development authorities. Environmental permitting for expansions engages agencies including the Environmental Protection Agency and state departments to address stream crossings and wetlands in the Ohio River Basin.

Auxiliary routes and spurs

Auxiliary connections and spurs link the corridor to regional destinations via numbered routes and business loops administered by state highway systems. Notable related corridors include connector freeways toward Pittsburgh International Airport, business route designations serving downtown Clarksburg, and state highway spurs providing access to institutions such as West Virginia University in Morgantown. Coordination of auxiliary designations falls under the purview of the American Association of State Highway and Transportation Officials for numbering and signing conventions.

Category:Interstate Highways in Pennsylvania Category:Interstate Highways in West Virginia