Design and Geospatial Services

THE PROJECT
The widening of U.S. 22/322 between the Harrisburg area and State College, home of Penn State’s main campus, has been an ongoing effort spanning decades. Widening the 6.5-mile section of the highway known as “Lewistown Narrows” from two lanes to a four-lane expressway posed significant challenges.

Within the project limits, the highway snakes through a geographically restricted corridor bounded by the Juniata River on one side and steep and rocky mountain slopes on the other. The two-lane highway had become dangerous, making the Reader’s Digest list of the 10 deadliest stretches of highway in the country in 1995. A representative of PennDOT, the project owner, described the initiative to widen the highway as “one of the most challenging engineering projects that PennDOT and its partners have ever tackled.”

As a subconsultant, Erdman Anthony completed preliminary engineering for the project, as well as final design for over 6 miles of new highway alignment, including a $2.5 million two-span bridge over Macedonia Run and an interchange. Our firm also provided survey and mapping services for the project.

FEATURES/SOLUTIONS
Fitting four lanes of new highway between the river and mountain slopes required that eastbound and westbound expressway lanes be bifurcated, with the westbound lanes sitting significantly higher than the eastbound lanes along the river. To accomplish this, the design included more than 22,000 feet of retaining walls, both along the river and in the median supporting the bifurcated mainline.

Stabilizing the mountain slope adjacent to the highway was also imperative. Working closely with PennDOT and the Federal Highway Administration, the design team developed a global stability system involving micropiles to stabilize the highway, and H-piles to serve as foundations for retaining walls and bridges.

Our firm also completed hydrologic and hydraulic modeling for the Juniata River and five tributaries, and we designed spring boxes, swales, and a storm water system that includes over 490 inlets and 5,400 linear feet of cross culvert. 

IMPACTS
The completed project, which local and national trade publications heralded as a noteworthy engineering feat, has improved travel times and safety. It also restored a section of the historic Pennsylvania Canal, remodeled a lock keeper's house into a park and educational center, and provided ramps to a boat launch on the Juniata River.

Awards

National award from the American Council of Engineering Companies (ACEC).

Multiple awards