Urban  designed the widening of the Pennsylvania Turnpike in Montgomery County, from two travel lanes in each direction, to three travel lanes in each direction, between the Mid-County Interchange (Exit #20) and the east/west Turnpike mainline north to milepost A26 (Berks Road).

The project is part of the Pennsylvania Turnpike Commission’s $2 billion statewide total reconstruction initiative which entails rebuilding sections of the 70-plus-year-old Turnpike facility from the ground, up. The new roadway design meets current interstate design standards, and will provide a safer and more efficient travel experience for Turnpike customers. It will also accommodate the growing number of vehicles on the roadway. Traffic volumes, currently estimated at 67,000 vehicles/day on this section of the Turnpike roadway, are projected to reach 100,000 vehicles/day by the year 2030.

One of the nation’s oldest limited access highways, the Turnpike right-of-way was largely established in the 1940s and 1950s. The challenge of incorporating 21st-century highway and stormwater management designs into a limited right-of-way and minimizing the impacts to adjacent residential and commercial properties was a key controlling aspect in the design.

In addition to the roadway, many other elements of sound engineering practices had to fit within the limited available “bandwidth”.  These included, but were not limited to, the embankment or cut slopes needed to support and accommodate the roadway widening as well as permanent roadway drainage features, stormwater management facilities, and E&S features to control surface water runoff and minimize the sediments and pollutants leaving the project site.

To limit land acquisition, retaining walls were designed to contain the fills and cuts to the extent possible. Urban worked closely with the Pennsylvania Turnpike Commission, state and local officials, the Montgomery County Conservation District, the local Townships and the Pennsylvania Department of Environmental Protection to develop the overall roadway and stormwater management system and details to satisfy the requirements for controlling surface water runoff from the site during and after construction while minimizing impacts to the residents. This coordination effort was critical in allowing the project to move forward.

Urban had previously prepared the Feasibility Study for the MP A20 – MP A30 corridor. Construction of the $191 million southern portion of this corridor was by Walsh Construction Co. of Canonsburg, Pa. The project was funded entirely by toll dollars and opened in October 2014.

The northern half of the full-depth reconstruction and widening project between milepost A25.6 and A31.3, including but not limited to the replacement of two overhead bridges and the construction of three auxiliary ramps in the vicinity of the Lansdale interchange, has been in construction since May 2014. Two travel lanes will remain open in each direction for the duration of the project scheduled to be completed by the end of 2016.

For more information on the six-lane expansion project on the Northeastern Extension, click here.