PennDOT announced plans to replace the I-376 Commercial Street Bridge in Pittsburgh after a 25-day closure this summer.
PennDOT hosted a virtual public hearing Wednesday to provide details on the agency’s ambitious plan to install a new $95 million bridge in less than a month — starting in July and opening in early August.
It will require Interstate 376 to close for 25 days.
The bridge is between the Edgewood/Swissvale (Exit 77) interchange in Swissvale and Squirrel Hill Tunnel in Pittsburgh. It spans over Nine Mile Run, Frick Park, and Commercial Street.
The plan is to demolish the 75-year-old I-376 bridge and “slide the new bridge” into place, PennDOT District 11 Executive Jason Zang said.
The new bridge will be 830 feet long and 60 feet high.
Sliding the bridge into place will take about 25 days. Zang said the contractors have monetary incentives and disincentives for every hour the bridge is not open, in either direction, beyond the 25 days.
The new bridge is being built directly next to the existing one, and, once it is completed and the existing bridge is demolished, the new bridge will be moved into alignment.
“The bridge weighs 22 million pounds and will be lifted by 42 jacks that will laterally slide the bridge into place,” said John Myler, PennDOT senior assistant construction manager for District 11.
The bridge will be “slid” about 100 feet in a matter of a few hours.
Zang said, while smaller-scale projects have been done moving pieces of bridges into place after construction, such an endeavor has not yet been attempted with a bridge of this scale.
“This is something different in its scale and move; it’s a unique engineering feat, and we are excited to be doing it here in Western Pennsylvania,” he said.
As of this week, construction of the new bridge is mostly completed, Myler said. A new bridge deck will be installed along with new barriers before a test run of the final move takes place in mid-June.
The closure will begin July 10, with the new bridge expected to open for traffic by Aug. 4.
Michelle Olszewski, senior project manager for the contractor, Fay S&B USA, said, during the 25-day closure, asphalt repair will take place in that stretch of the parkway. The project also includes repairs to highway lighting between the Squirrel Hill tunnel and the turnpike.
Clint Filges, Fay’s vice president of demolition, said an 800-foot blast perimeter will be established when the bridge is destroyed. Residents are not encouraged to attempt to watch due to the large blast perimeter, and officials said they are working to set up a livestream link for an up-close view of the teardown.
“It is not much of a spectacle to actually watch,” Filges said. “It is just going to sound like a very loud clap of thunder, with a little bit of smoke.”
The project, unveiled nearly eight years ago, is fully funded by the Federal Highway Administration.
Those attempting to navigate around the closure are advised to plan ahead, and employers are encouraged to enforce work-from-home policies, as navigating around the closures will likely lengthen commutes.
Myler said that the routes around Frick Park will have local detours to better serve community members and local businesses. PennDOT is working to establish carpool sites at major bus stops through coordination with Pittsburgh Regional Transit and Westmoreland Transit.
“The more cars we have off the road, the better traffic is going to flow,” he said.
Local residents can utilize the website 511pa.com and the coordinating app to get up-to-date traffic updates for the recommended detours.