Pennsylvania Department of Transportation

SR 322, Section 100 Corridor Improvements & Widening

Delaware County, PA

SR 322 is an east/west principal arterial in the suburban Philadelphia region. The Section 100 corridor extends seven miles from just west of the I-95 interchange to the US 1 intersection. The roadway is locally known as Conchester highway and includes parts of three townships: Concord, Bethel, and Upper Chichester in Delaware County. This portion has two typical sections, a two-lane section beginning at US 1 intersection, which widens into a four-lane divided highway as it extends past the Cherry Tree Road intersection, to the eastern end of the project area. Nine major intersections are included, some of which are grade separated.

Existing problems include traffic congestion, high accident rates, uncontrolled access, lack of adequate capacity to accommodate planned growth in the corridor, and geometry that does not meet current design standards. Given the availability of “reserved” PennDOT right-of-way to the south side of the roadway and the presence of development in the US 322 corridor, only widening improvements were considered.

Benesch’s services included preliminary engineering studies, environmental studies, final design and construction consultation. The final design alternative for the US 322 corridor included the introduction of two additional lanes south of the existing roadway. In addition to increasing the number of lanes, a grassed median will be utilized to control access to the US 322 corridor along with left turn lanes and adaptive traffic signal systems to increase the capacity of existing intersections. The project involved the design of three miles of non-motorized paths, five bridges, eight culverts, sign structures, ITS devices, retaining walls and sound barriers. The project will be built in three construction contracts (Sec. 101, 102 & 103) with a fourth contract (SR 3025/MIT) for construction of mitigation measures.

Project highlights

  • Over 400 impacted properties
  • Traffic enhancements include ITS and Adaptive Signalization
  • Stakeholder-driven grass median provides additional stormwater management BMP opportunities in existing roadway footprint
  • Off-site (Thornbury Township) wetlands mitigation site expansion