Penn State research helps build new Rothrock State Forest greenway

January 22, 2013

UNIVERSITY PARK, Pa. — When a new greenway gives the Penn State community and area residents a direct access to Rothrock State Forest, the surface material will be a unique stone mix developed by researchers at the Thomas D. Larson Pennsylvania Transportation Institute's Center for Dirt and Gravel Road Studies at Penn State. The Musser Gap Greenway, scheduled to open in the fall, will extend 1.4 miles from the Musser Gap parking lot northwest to Whitehall Road near Blue Course Drive.

Researchers at the center developed a specialized stone mix called Trail Surface Aggregate, or TSA, in response to the need for a stone mix for non-motorized use paths that resists erosion and is low maintenance. The designer of the greenway, Stahl Sheaffer Engineering LLC selected Penn State's TSA for the project.

"TSA was developed based on computer modeling to create a mix of various stone sizes that bind together well," said David Shearer, a field operations specialist with the center.

The TSA product is a spinoff from the center's better known Driving Surface Aggregate, a Pennsylvania Department of Transportation-specification mixture that has been applied successfully to unpaved roads.

Shearer said the developers of the TSA ensured that the new mix would be comprised of stone that is available from all of Pennsylvania's quarries. TSA can also be prepared using a "recipe approach" to accommodate small-scale projects.

Existing applications of the TSA include walking paths at the Centre Furnace Mansion and Shaver's Creek Environmental Center in Centre County,  and several sections of rails-to-trails pathways, including 12 miles of the Pine Creek Trail near Slate Run in Lycoming County.

ClearWater Conservancy purchased the Musser Gap property in 2006, added a parking lot to make it publicly accessible, and then transferred it to the Department of Conservation and Natural Resources (DCNR) Bureau of Forestry in 2007. The conservancy is now partnering with Penn State, which owns part of the surrounding land, to create this greenway connection.

"The TSA is an important part of this recreational access project, and we are thankful for our partners at Penn State and the Larson Institute," said Katie Ombalski, a conservation biologist with ClearWater Conservancy. "Durable, locally sourced materials make for cost-effective, long-lasting projects."

"This has been in the works for a long time, and I'm happy that all of the stakeholders were able to come together and provide the resources to create this important link between State College and the Musser Gap," said Rob Cooper, director of energy and engineering at the Office of Physical Plant at Penn State. The University provided funding and project management services.

Grant funding for the greenway was provided by the DCNR Community Conservation Partnership Program, Department of Community & Economic Development, Bikes Belong, Kodak American Greenways, Penn State Office of Physical Plant, Ferguson Township and State College Borough.

  • Penn State's Trail Surface Aggregate was placed on footpaths at the Shaver's Creek Environmental Center in Centre County.

    IMAGE: Michael Casper

(Media Contacts)

Last Updated February 08, 2013