Rapid growth in the Philadelphia region represented by numerous suburban office parks, retail shopping centers and residential development has contributed to severe and growing congestion on the Pennsylvania Turnpike's Southeast corridor and the surrounding highways.

"To accommodate current and future traffic demands and provide a safer, more comfortable and convenient roadway for travelers and commuters in the Philadelphia area, the Turnpike plans to widen the highway from Valley Forge to Norristown and from Mid-County to Lansdale from four to six lanes," said Turnpike Executive Director John T. Durbin,"

This widening project will add to the 17 miles of Turnpike that was widened to six lanes in the 1980s from the Northeastern Junction (Mid-County Interchange #25A) to the Philadelphia Interchange #28.

The Turnpike Commission in January 1999 began a feasibility study for the proposed widening covering 16 miles in Montgomery County: 5.8 miles of the east/west mainline Turnpike from Valley Forge Interchange (exit 24) to the Norristown Interchange (exit 25), not including the Schuylkill River Bridge, and 10.3 miles from Mid-County Interchange (exit 25A) to the Lansdale Interchange (exit 31) on the Northeastern Extension (I-476). The project is estimated to cost approximately $200 million.

Working closely with local officials in Montgomery County, Plymouth and Upper Merion Townships, the Commission has divided the study into two distinct sections -- the east/west mainline Turnpike widening which requires no Federal Highway Administration (FHWA) approval, and the Northeastern Extension (I-476) Turnpike widening which requires widening the median, replacing overhead bridges, and FHWA approval for all phases of design.

The feasibility study for the east/west portion of the Turnpike from Valley Forge to Norristown is scheduled for completion sometime in April/May. Originally opened to motorists in 1953, this critical section of the highway bears one of the highest traffic volumes of any four-lane section of the Turnpike, carrying approximately 55,000 vehicles daily. Recent studies forecast that traffic in this corridor will increase dramatically to approximately 75,000 vehicles daily by 2020.

To accommodate the future widening of the Turnpike in this corridor, the Turnpike began construction on the $35 million Schuylkill River Bridge/Diamond Run Viaduct in the spring of 1997. In June 1999 a new 1,224-foot six-span steel girder for the Schuylkill River Bridge was completed. Currently, construction crews are working on the rehabilitation of the existing bridge, which is scheduled for completion in June.

The Turnpike in the area under study for lane widening has four 12-foot wide lanes, with 10-foot shoulders. Originally built in the 1950's, plans are for the existing highway to be completely reconstructed and widened. Plans for the new highway include six 12-foot-wide lanes with 12-foot-wide outside shoulders, new guiderails and concrete median barriers. The bridges carrying the Turnpike over local roads will be widened and re-decked or replaced to accommodate the six lanes of traffic and full outside shoulders.

Retaining walls are planned to help minimize impacts of the widening and avoid right-of-way problems. Four lanes of traffic will be maintained throughout construction, limiting impact on this highly congested commuter corridor.

Construction of the six-lane widening of the Turnpike between Valley Forge Interchange (exit 24) and the Norristown Interchange (exit 25) is scheduled to begin in 2003.

The feasibility study for the Northeastern Extension (I-476) is more complex since the existing median is only four feet wide. Urban Engineers will design a preliminary expansion plan for the 10-mile section from Mid-County Interchange to the Lansdale Interchange, which includes plans for a proposed slip ramp south of the Lansdale Interchange. As part of its public outreach program, the Turnpike's project team will meet this spring with township and county officials, transportation agencies, Transportation Management Associations and legislators in the communities to discuss the widening project.