PennDOT to replace Parkway East bridge
New Commercial Street Bridge built next to old
The Pennsylvania Department of Transportation will replace the Commercial Street Bridge section of the Parkway East approaching the inbound Squirrel Hill Tunnel by building the new bridge beside it and sliding it into place.
The project is about two years away, but after several years of studying it the department has determined that method would cause the least disruption for the 100,000 motorists who use the bridge daily during normal times. PennDOT will hold an online public meeting about the project at 5 p.m. Wednesday.
PennDOT and consultant HDR also had been considering putting all traffic on one side of the bridge while crews rebuilt the other side, but they decided that would be too disruptive. Instead, whoever wins the contract will build temporary pillars on the north or left side of the bridge approaching the tunnel, construct the new bridge there, and slide it into place when the existing bridge has been demolished.
The current estimate is that the highway would have to be closed in that area for about two weeks for demolition, placing the new bridge and connecting it with existing approaches. PennDOT has committed $123 million to the project, which could take five years to complete.
The idea of building a bridge at another location and moving it into place isn’t new. In 2017, the Pennsylvania Turnpike replaced a bridge in Beaver County by building the new one next to it and sliding it in place and PennDOT built
the new Shaler Street Bridge over Route 19/51 near the West End Bridge in a nearby parking lot and used hydraulic trailers to move two large pieces into place.
But Commercial Street will be a much larger, more challenging project.
The massive concrete arch bridge is 861 feet long and stands 80 to 85 feet above the valley below it. The new bridge will have wider shoulders, pushing its width to about 90 feet.
Crews also will have to work from Commercial Street, which runs through the valley under the bridge and includes the Swisshelm Park neighborhood, Frick Park and the Nine Mile Run watershed. PennDOT officials were unavailable Friday to talk about details of the project.
The bridge opened in 1951 and has been through at least three major rehabilitations, but PennDOT believes it now needs to be replaced. The structure has concrete spalling in numerous areas, cracks as wide as a quarter inch, and the condition of the deck, floor system and support columns prevent it from carrying oversized loads. Without major work or replacement, the bridge could face weight restrictions, which would be a major problem on an interstate highway.
To watch or participate in Wednesday’s meeting, go to PennDOT’s District 11 website.