For almost two years, the road under the Parkway East at the bottom of Frick Park sat about 150 feet west of its usual path, and the Nine Mile Run Trail moved over with it. How much of the old trail and the woods around it comes back now?
The road comes back first. PennDOT scheduled a closure of Commercial Street/Forward Avenue and the Nine Mile Run Trail from 8 p.m. Friday, Oct. 16, to 8 p.m. Saturday, Oct. 17, so crews could do final paving and "realign Commercial Street back to its original location." That weekend was set to close out the part of the $95 million Commercial Street Bridge replacement that neighbors could hear. The phase starting now is quieter and runs longer. On paper, it leaves the lower end of the park with more planting than it had before crews cleared the site, plus a large addition planned next door.
Two years spent 150 feet to the west
The detour began on Oct. 31, 2024. PennDOT moved Commercial Street and the trail beside it about 150 feet west of the I-376 bridge to make room for bridge staging, and expected the new layout to stay through summer 2026. The Pittsburgh Parks Conservancy explained that the original trail ran right through the active work zone. The road also had to make room for the new bridge's temporary foundations, built right next to the old span.
After that, the trail closed completely twice.
| Period | What happened at the bottom of the park |
|---|---|
| Oct. 31, 2024 | Commercial Street and the Nine Mile Run Trail shift about 150 feet west |
| Nov. 24, 2025 to Feb. 13, 2026 | Round-the-clock closure of the road and trail for steel and beam work. The start slipped a week because steel erection ran late, and winter weather pushed the end back from Feb. 6 |
| June 29 to Aug. 3, 2026 | Second round-the-clock closure for the demolition and bridge slide |
| July 10 to July 27, 2026 | The Parkway East itself closed |
| Oct. 16 to 17, 2026 | Overnight-to-evening closure for final paving and the move back to the original alignment |
Each closure covered the same stretch, from the Nine Mile Run parking lot in Swisshelm Park to the Frick Park Commercial Street lot on the Squirrel Hill side. BikePGH spelled out what that meant on the ground during the summer closure. The trail's north and south halves couldn't connect at Commercial Street, so riders coming up from Duck Hollow could reach the trail lot but then had to turn around or climb Commercial Street toward Swisshelm Park. For commuters between Browns Hill Road and the East End, BikePGH suggested Parkview Boulevard through Summerset at Frick to Commercial Street.
July was the loud part
The summer closure is the one most people remember. The old bridge came down by explosive demolition at about 8 a.m. on July 16. The new bridge started sliding sideways into place at about 10 a.m. on July 19. PennDOT reported that the bridge moved 96 feet in seven hours that Sunday, riding on 42 skid shoes with hydraulic jacks, and crews finished the last six feet Monday morning.
Because of the blast, Frick Park was part of the safety zone. The Post-Gazette reported that the safety perimeter reached into the park, so there was no public spot to watch near the blast, and people were pointed to PennDOT's livestream. Ahead of the work, PennDOT District 11 Executive Jason Zang told WESA that demolition and site work would be very loud and that park security would keep people out of areas at risk from debris.
After the slide, the park became the viewing spot. A Post-Gazette photo from July 20 shows a Regent Square resident stopping on a morning walk in Frick Park to photograph the new bridge, and Mammoet project manager Fernando Cajeli called the move a major milestone. When the Parkway reopened on July 27, a week ahead of the Aug. 3 target, a Squirrel Hill resident told WTAE the construction method was unlike anything he had seen. Commercial Street and the trail reopened on Aug. 3, though still on the temporary path.
What the October weekend was for
Moving the road back was scheduled as the last step that needed the whole route cleared. PennDOT's plan closed Commercial Street/Forward Avenue between Whipple Street and Summerset Drive, plus the trail between the two parking lots. The posted detour sends drivers by way of Whipple Street, Monongahela Avenue, South Braddock Avenue, Forbes Avenue and Beechwood Boulevard. The agency said the closure depended on the weather and could end early if crews finished sooner.
Even once the road is back in place, the project isn't finished. PennDOT's project page, updated Oct. 13, 2026, still lists summer 2027 for completion. The full project also includes an eastbound retaining wall, lowering the westbound Exit 78B ramp, sewer relocation, new signs and barriers, and restoration of the Frick Park and trail areas. PennDOT's releases don't say which of those items are still open.
The last phase is replanting
Park users will notice this phase the most, and it comes last. PennDOT's project FAQ says that restoring trails and landscaping "is part of the project's final phase, ensuring full access and environmental compliance."
The Conservancy's 2024 account gives a sense of how much that involves. Most of the trees removed during clearing were turned into brush piles for wildlife until replanting can happen. The contractor, Fay, S&B USA Construction, plans to plant more than 5,000 trees and shrubs, which the Conservancy describes as well over the amount originally cleared. Compost filter socks went in along the stream's 100-year floodplain to keep sediment out of the water, and a temporary equipment crossing let machines cross Nine Mile Run without driving through it.
PennDOT's FAQ also describes a separate review of the stream plans by the watershed group Upstream Pittsburgh.
Upstream Pittsburgh was consulted during the design of this project, and they reviewed all plans associated with the temporary disturbance of Nine Mile Run underneath the bridge structure during construction (i.e., construction vehicle causeway crossover), as well as the final restoration of the creek to make sure it is returned to equal or better conditions than exist today.
The same answer says runoff from the area flows through a rain garden before it reaches the stream. That stream matters well beyond this one spot. Upstream Pittsburgh's map of the Nine Mile Run watershed covers Squirrel Hill, Swisshelm Park, Regent Square, Point Breeze, Homewood and East Hills, plus Edgewood, Swissvale and Wilkinsburg.
Next door, a former slag dump is on its way to becoming park
The trail lot has a second construction neighbor. PennDOT's FAQ says the lot stays open during the bridge project, but the Urban Redevelopment Authority plans to use it as an access point for its own project, so people should watch for construction vehicles coming and going.
That project is Swisshelm Park Solar. The URA is cleaning up a Swisshelm Park site that was once an industrial dumping ground for slag. Once that's done, it plans a solar array on about 15 acres and will transfer part of the property to the City of Pittsburgh to extend Frick Park. For decades, the URA had planned housing here as the third and final phase of Summerset at Frick Park. The solar plan replaces that idea. The URA's page describes the future park extension as nearly 55 acres. It says cleanup was mostly done by November 2025, with punch-list work left for spring 2026, and estimates the cleanup will be substantially complete in the fourth quarter of 2026.
The solar schedule isn't firm yet. In April 2026, the URA approved a 25-year lease with Capital Good Fund for the array. The Post-Gazette reported that the array is meant to offset electricity use at four Pittsburgh Public Schools, and that construction is expected to start and finish in 2028. The URA's own page lists solar construction for 2027.
Taken together, the bridge's replanting and the slag site's cleanup put more planted land and more parkland on the way for the lower end of Frick Park than it had in 2024.
Where the whole trail goes again
Once Commercial Street is back on its original line, the trail runs end to end through the bottom of the park on its permanent route. The Conservancy describes the Nine Mile Run Trail as a 3.5-mile route along the stream through Frick Park. Its Frick Park entrance guide lays out the connections:
- Lower Frick parking lot: Nine Mile Run Trail, Tranquil Trail, Falls Ravine Trail and Firelane Trail, with links to lower Nine Mile Run and the Frick Environmental Center
- Commercial Avenue access: Nine Mile Run Trail and Fire Lane Trail, connecting to the lower lot, Duck Hollow, Iron Gate Trail and the Firelane Extension Trail
- Duck Hollow: Nine Mile Run Trail, Duck Hollow Trail, a parking lot and the Monongahela River
At Duck Hollow, according to Upstream Pittsburgh, Nine Mile Run empties into the Monongahela. If you want updates on the replanting phase, PennDOT posts them on its Commercial Street Bridge project page, and it also runs an email list for Parkway East construction advisories.
If you've been following the bridge from the Nine Mile Run Trail and want to talk through how Squirrel Hill's corner of Frick Park keeps changing, from the new plantings to the planned park extension next door, Miranda Micire would love to hear from you. Contact Us anytime.
