The final scheduled weekend closure at the Squirrel Hill Tunnel, this one on the outbound side, is expected to cause major delays today and Sunday on the Parkway East and on neighborhood streets that will swell with diverted traffic.
A second potential trouble spot will be on Interstate 79 in Marshall, which will have single-lane traffic in both directions this evening through Sunday morning.
The tunnel closure was scheduled to begin at 10 p.m. Friday and continue until 6 a.m. Monday. All traffic is being merged into one lane that exits at Squirrel Hill-Homestead (Exit 74).
The closure coincides with the continuing P&G Gymnastics Championships, a national event taking place this weekend at Consol Energy Center.
More than 2,000 people also are expected to participate today in Run Around the Square, a 5K race in Regent Square, which is along the posted detour route.
The Pennsylvania Department of Transportation could not delay the closure until next weekend because of the Labor Day holiday; the next weekend is the Steelers’ regular-season opener. The Pirates are at home the two weekends after that.
“There’s always something happening in the city of Pittsburgh,” PennDOT spokesman Steve Cowan said this week.
“While we don’t like to impact anyone, when we do projects of this nature, it’s going to impact somebody.”
The closure will allow the contractor on the $49.5 million project to pave the tunnel, place tiles, work on a water line and clean sandstone and brick at the tunnel portal, Mr. Cowan said.
The inbound tunnel will be open, but traffic might be stopped briefly as equipment is moved.
The posted daytime detour follows Forward Avenue, Beechwood Boulevard, Forbes Avenue and South Braddock Avenue.
After 8 p.m., PennDOT is asking motorists to use Murray Avenue rather than Beechwood Boulevard.
Past tunnel closures have caused delays of as long as two hours.
An alternate detour is to exit from the outbound parkway at Forbes Avenue in Oakland (Exit 72A) and follow Forbes, South Bellefield, Fifth and Penn avenues to reach the parkway on-ramp at Forest Hills.
The PennDOT District 11 website will display estimated travel times and traffic camera views from the posted detour route during the tunnel closure.
On I-79, traffic will be one lane in both directions from 7 tonight until 9 a.m. Sunday as crews patch the concrete pavement.
The northbound work zone is between Route 910 Wexford (Exit 73) and Route 19 Cranberry (Exit 76). Southbound, the work will occur from the Butler County line to the on-ramp from Route 19.
Jon Schmitz: email@example.com, 412-263-1868 or on Twitter @pgtraffic.