The MP 308-312 Mainline Total Reconstruction Project is located just to the west of the Downingtown Interchange of the Pennsylvania Turnpike. The project involved the widening of the mainline turnpike from four lanes to six lanes and also increased the width of the median and shoulders to meet current Turnpike standards.
In addition, the project involved the replacement and lengthening of several mainline and overhead structures, including those at Route 100, Milford Road, Styer Road, Park Road and Little Conestoga Road. The project involved the installation of multiple stormwater management facilities, the relocation of utilities the construction of noise walls and retaining walls, and approximately 40 partial property takes.
TPD served a subconsultant to Gannett Fleming for this agreement and was responsible for the design of the structure carrying Milford Road over the PA Turnpike (pictured), the preparation of all Right-of-Way Plans and Property Plats and the preparation of the Phase I Environmental Site Assessment.
TPD was responsible for the design of the structure carrying Milford Road (Twp) over the PA Turnpike. The existing structure is a single span, steel through girder structure on full height abutments. The proposed structure is a 2-span Continuous Composite Prestressed Spread Box Beam Bridge on mid-height abutments. The new structure was lengthened to handle the proposed six-lane mainline cross section. The existing approaches to the structure along Milford Road and the structure itself were slightly widened to accommodate a future pedestrian trail along the east side of Milford Road. The existing vertical and horizontal geometry were generally maintained. TPD was also responsible for the design of two access ramps from Milford Road to the PA Turnpike as part of the design of the structure. Each ramp is approximately 1,000 feet in length.
TPD was responsible for the preparation of the Right-of-Way Plans and Plats along the entire four-mile length of the section. It was anticipated that a total of 40 properties were impacted due to the widening, installation of noise walls, and the construction of temporary and permanent stormwater management facilities.
The Phase I Environmental Site Assessment involved the PADEP file review and site reconnaissance with respect to the potentially hazardous wastes sites along the PA Turnpike and at all side roads. TPD also conducted interviews with the property owners and prepared/submitted the Phase I ESA report for review the PA Turnpike Commission.
