After years of planning and design, preliminary work on the $95 million I-376 Commercial Street Bridge Replacement project between the Edgewood/Swissvale (Exit 77) interchange in Swissvale Borough and Squirrel Hill Tunnel in the City of Pittsburgh began in June. This project will use Accelerated Bridge Construction (ABC) techniques to laterally slide the 825-foot-long proposed bridge onto the existing alignment of I-376, which will be one of the largest lateral slide projects ever performed in Pennsylvania.
“This project will have major short- and long-term impacts to the motoring public, but also the local communities surrounding the bridge," said PennDOT District 11 Executive, Jason Zang. “The significance of performing an ABC technique of this magnitude along the interstate is monumental to minimize construction delays. I'm confident our staff, along with the wonderful contractors, can produce an outstanding bridge replacement for the Pittsburgh region."
Work also includes installation of new overhead signage, an eastbound retaining wall, concrete median barrier replacement, sanitary sewer line relocation, upgrades to guide rail, ITS Devices, CCTV Cameras, Over Height Truck Detection System replacement, as well as overall site restoration for both Frick Park and the Frick Park walking trail. Additionally, crews will work to increase the vertical clearance under mainline I-376 to accommodate truck traffic by lowering the westbound I-376 off-ramp to Forest Hills/Wilkinsburg Interchange (Exit 78B).
The Commercial Street Bridge was built in 1951 and has since undergone three rehabilitation projects in 1980, 2007, and 2012. Today the bridge carries about 100,000 vehicles per day, however, it does not allow permit loads due to an insufficient load-carrying capacity.
During the design process, it was decided the new bridge would use a Steel Arched Delta Frame Structure to mimic the existing historic arch design and add to the aesthetics of the Frick Park and trail beneath the bridge. In 2023, the department asked the public to vote on the color of the new bridge by visiting the PennDOT District 11 website. After receiving almost 1,000 votes, the participants elected to paint the bridge green to match the nearby Greenfield Bridge, which underwent a full replacement over I-376 in 2017.
To continue open communication with the local communities and stakeholders, there will be two public meetings held during the construction phase. The first public meeting will be held this summer, while the second will be held approximately two months prior to the full closure and detour of I-376 in the summer of 2026. The meeting will review construction activities in advance of the lateral slide, and detail traffic control restrictions.
“The motorists and the local residents play such an important role in this process," said Zang. “We want to make sure not only do they know what to expect during the full closure, but also have the opportunity to provide feedback."
Minor restrictions on the road began in mid-June, in preparation for the project. Motorists can expect to see short term single-lane and shoulder restrictions on weekends and weeknights in both the westbound and eastbound direction along I-376 as needed through 2026 in advance of the lateral slide. Additionally, this summer, the westbound I-376 off-ramp to the Forest Hills/Wilkinsburg Interchange (Exit 78B) will be closed and detoured for 36 consecutive days to reconstruct the exit ramp and increase the vertical clearance under mainline I-376.
In 2025, there will be approximately ten weekend-long single lane closures of eastbound I-376 to construct a retaining wall. There will also be approximately nine overnight full closures and a detour of eastbound I-376 to deliver fabricated structural steel to the project site and one weekend full closure and detour in each direction for overhead sign installation.
In 2026, Commercial Street and the Frick Park walking trail are anticipated to be closed for approximately 122 consecutive days for the removal of the existing structure and reconstruction of both Commercial Street and the Frick Park walking trail along their existing alignments. A 25-day full closure and detour of I-376 in each direction of I-376 will occur to conduct the lateral slide of the new bridge. The overall project is anticipated to conclude in the Summer of 2027 after the Site Restoration Plan has been implemented.
This is just one of several projects occurring during the next several years to improve the Parkway East. Currently, I-376 is undergoing a $70.16 million betterment project between the Churchill/Route 130 (Exit 79B) and Monroeville/Route 48 (Exit 84A) exits. Future projects include the estimated $94.7 million Active Traffic Management project from the Fort Pitt Bridge in the City of Pittsburgh to the Turnpike (Exit 85) in the Municipality of Monroeville, the estimated $50 million betterment project between the Commercial Street Bridge in the City of Pittsburgh and the Business Route 22 interchange in Churchill Borough, the estimated $50 million barrier replacement project between the Fort Pitt Bridge and Squirrel Hill Tunnels, and the estimated $35 million Bathtub Flood Wall reconstruction project between the Grant Street (Exit 71A) exit and Fort Pitt Bridge. With millions of dollars being invested in the Parkway East, District 11 is thrilled to provide the region with quality projects to enhance the southwestern Pennsylvania's infrastructure.
For more information on the Commercial Street Bridge Replacement Project, please visit PennDOT's website.