Challenge

PennDOT Engineering District 9-0 was faced with a dilemma. A 1950s interchange with antiquated design features on Scalp Avenue at Belmont Street had numerous crashes and it formed a barrier to pedestrian and bicycle travel within Geistown. The bridge at the heart of the interchange was also nearing the end of its useful life. Traffic at the interchange wasn’t nearly as high as was projected when it was built, suggesting a number of possible options.

Solution

As a sub to Prime AE, Kittelson performed a traffic analysis for the development of alternatives for the replacement of the interchange. In addition to alternatives that would maintain an interchange at the location, the team found that an at-grade roundabout and an at-grade signalized intersection were effective at handling the projected traffic volumes. Ultimately, through extensive community involvement, a roundabout was chosen as the preferred alternative because of the opportunities to improve safety and enhance the community environment. In conjunction with this project, the team evaluated road diet alternatives for the approach roadways to reduce the four-lane typical section to three lanes in the vicinity of the project to further improve safety. We conducted a Highway Safety Manual analysis and prepared a Highway Safety Improvement Program application to PennDOT Central Office that secured $2.5M in funding for the project.