By Joe Genco

Eagle Staff Writer

MARSHALL TWP, Allegheny County — Cars going from Cranberry Township toward Gibsonia on the Pennsylvania Turnpike will be driving through a major construction zone in coming years.

The Pennsylvania Turnpike Commission plans to replace three bridges and widen a 2.4-mile stretch of the highway that starts in Cranberry Township.

The plans for the reconstruction project were on display Wednesday night at a Turnpike Commission open house at Marshall Middle School.

The $76 million project is planned to start in 2019 and finish by 2021. Right-of-way acquisition and final planning will start next year, said Neil Raup, engineer with the Turnpike Commission.

This project is part of an ongoing $2.5 billion reconstruction program that started in 1999 and is funded entirely by toll revenue.

The plans include widening the Turnpike from four lanes with a 10-foot median to six lanes with a 26-foot median between the Warrendale toll plaza in Marshall Township and the Cranberry interchange, just north of the county border. The interchange between Interstate 79 and the Turnpike will not be affected.

The $6.4 million replacement of the Thorn Hill Road bridge over the Turnpike, which also is considered part of the project, was completed last year.

While widening the highway will allow for more traffic to pass through, the main reason for adding a lane in each direction is to allow for four lanes of traffic during nearly the entire construction process, which minimizes delays for motorists, Raup said.

Widening the median makes the highway safer by providing more space for motorists to pull over in the event of an emergency, he said.

The bridge carrying traffic over Route 19 just south of the intersection with Thorn Hill Road will be torn down and replaced. That bridge is getting to be structurally deficient, which is one reason the project is moving forward sooner rather than later.

The clearance of that overpass will be raised slightly to accommodate larger trucks.

Contractors will work to limit the effects on local traffic, Raup said.

“This should have a minimal effect on Route 19. When they demolish the old bridge and when they set the beams for the new bridge is when you will see some weekend closures or restrictions,” he said.

Two brief closures of the Turnpike itself also will be done between midnight and 6 a.m. on Sunday mornings to affect the fewest motorists as possible, Raup said.

The project also includes replacing the bridge over Mount Pleasant Road and replacing a bridge over an unnamed tributary to Brush Creek with a box culvert, both in Marshall Township.

The reconstructed portions of the Turnpike are expected to last 50 years.

A similar reconstruction project at the Allegheny Valley interchange in Allegheny County was completed earlier this year.

In an unrelated project, the state Department of Transportation and Turnpike Commission also plan to replace the bridge carrying Freedom Road over the Turnpike in 2018. The Freedom Road replacement is estimated to cost $9 million and will include widening the bridge to accommodate four lanes of traffic.