What to Expect from the Commercial Street Bridge Replacement Project

THE COMMERCIAL STREET BRIDGE ALONG THE PARKWAY EAST, AS SEEN FROM FRICK PARK. THE BRIDGE WILL BE DEMOLISHED IN 2026 AND REPLACED BY A NEW BRIDGE BUILT BESIDE IT | PHOTO BY VIRGINIA LINN

If you regularly travel the Parkway East, you’ve probably heard of the Commercial Street Bridge replacement project, and by now, you’ve probably seen the new bridge being built just south of the existing structure on temporary foundations. 

For some motorists, it is a looming omen of what’s to come.

In July, workers will demolish the current bridge and move the new one in in its place, resulting in a 25-day full closure and detour of I-376 between the Squirrel Hill Tunnel and the Edgewood/Swissvale (Exit 77) interchange. Closures will begin on July 10 and last through Aug. 3, rerouting the more than 100,000 vehicles that travel the highway — one of the most heavily traveled in Western Pennsylvania — each day. 

Construction company officials say sliding the bridge in, known as the sliding ABC method, was chosen over staged construction because the technique will minimize the impact of traffic on the roadway, but drivers are still expecting heavy delays and heavier traffic along detour routes, such as Route 28, I-79 and the Pennsylvania Turnpike, I-76. 

Some folks who travel the roadway daily are even planning their summer vacations around the dates to avoid it altogether — something even PennDOT officials themselves have suggested. PennDOT also encourages folks to work from home if they can, take public transportation when they can and have all the supplies they may need while waiting in heavy traffic — including snacks and water for your passengers, good music or an audiobook to listen to, comfortable clothing, sunglasses and anything else that allows you to drive comfortably.

To minimize the traffic disruptions and to ensure the timeline is followed, PennDOT also says there is a “monetary incentive” available to the construction team for completing the work early. If the project runs past the 25-day timeline, there are financial disincentives for the contractor that will total in the millions. 

PennDOT will also coordinate with local communities, utilities providers and other entities to ensure no construction work is being performed on detour routes while the detours are in place. Additionally, traffic signals along the detour routes have been analyzed and modified to accommodate the new traffic flow.

Work will also include the installation of new overhead signage and an eastbound retaining wall; lowering the westbound I-376 off-ramp to Forest Hills/Wilkinsburg Interchange (Exit 78B) to increase vertical clearance under the Parkway East; concrete median barrier replacement; sanitary sewer line relocation; upgrades to guide rail, ITS devices,overheight truck detection systems and CCTV cameras; and overall site restoration for both Frick Park and the Frick Park walking trail.

The completed bridge will weigh just over 19 million pounds, or 9,000 tons. The project will use 7.4 million pounds of structural steel, including an 825-linear-foot steel delta frame girder with seven girder lines, 11,800 cubic yards of concrete and 275 linear feet of retaining wall.

State and construction company officials say public awareness throughout the project is vital to its success. From 5 to 6:30 p.m. on May 13, PennDOT and S&B USA Construction will host a virtual public meeting to discuss the I-376 Commercial Street Bridge Replacement Project. This briefing offers the opportunity to hear about the upcoming traffic I-376 closure and future work plans, with a Q&A session with the project team. To join the meeting via Microsoft Teams, follow this link.