Street, trail in Frick Park under Commercial Street Bridge to close for 10 weeks beginning Monday

More traffic disruptions begin on Monday related to the project to replace the Commercial Street Bridge on the Parkway East.

Beginning at 7 a.m. Monday, Commercial Street/Forward Avenue and the Nine Mile Run Trail in Frick Park underneath the bridge will close for nearly 10 weeks. The closure will allow crews for Fay S&B USA to build arches for the new bridge.

The Commercial Street Bridge is the structure just outside the outbound end of the Squirrel Hill Tunnel that carries about 100,000 vehicles a day. The Pennsylvania Department of Transportation is using an innovative process to replace the bridge, building the new structure on the park floor about 25 feet away from the current one, which will be torn down next summer and the new 861-foot bridge will be slid into place.

So far, crews have assembled 1½ of the four arches that will support the new bridge, the arches nearest the tunnel. The department is closing the road and trail under the bridge so it can build the arches at the far end that will pass above them because it would be unsafe for them to be active during work.

During this phase of construction, Commercial Street/Forward Avenue will be closed between Whipple Street and Summerset Drive. The trail will be closed to all bicycle and pedestrian traffic between Nine Mile Run parking lot on the Swisshelm Park side and the Frick Park Commercial Street parking lot on the Squirrel Hill side until Feb. 6.

Detours will be posted.

This is the latest traffic restriction related to the complicated project. Outbound traffic was limited before the tunnel during the daytime for several months earlier this year while crews built a retaining wall just outside the tunnel near the Summerset at Frick housing complex, and there have been intermittent restrictions during daytime hours for trucks with steel beams that follow an outbound route through the tunnel, then cross over the inbound lanes to take beams down a temporary road into the building area in the park.

When the arches are finished, the roads will reopen while crews finish building the decks on top of the arches. Contractors are on a very tight schedule to have the new bridge finished by July, when the Parkway East will be closed for 26 days while a special consultant uses hydraulic jacks to push the new bridge about 1 foot an hour until it lines up with the existing roadway.

The roads and trail will be closed again during that process.