Transit riders between Downtown Pittsburgh and the South Hills can expect about eight months of disruptions beginning next Sunday.
That’s when Pittsburgh Regional Transit will close the Mount Washington Transit Tunnel for a $26 million makeover. The tunnel, which connects Station Square with South Hills Junction, is the only one in the country shared by buses and a light rail system.
As a result of the closure, light rail trains will use the old Blue Line system through Allentown, which usually is closed. A temporary stop will be added at Allen Street for riders in that area.
Then the trains will go into Downtown Pittsburgh via the Panhandle Bridge without stopping at Station Square. Riders who want to go to Station Square can take a free shuttle from the First Avenue Station.
The tunnel closure also will cause changes for riders who use the Silver Line. On weekdays, that system will operate between the Library Station and Washington Junction, where riders who want to continue will have to transfer to the Red or Blue Line to reduce congestion in Allentown.
All three lines will operate through Allentown on weekends, when trains run less frequently.
Ten bus routes that normally use the tunnel will be rerouted through Allentown. Instead of using the Panhandle Bridge, they will go on East Carson Street and turn right at the Smithfield Street Bridge to get into Downtown.
The rerouting is expected to add seven or eight minutes to a full trip.
Outbound service will be the reverse of inbound trips on the light rail system, but it will be different for buses.
Most outbound buses leaving Downtown Pittsburgh will cross the Smithfield Street Bridge and turn right on East Carson Street and left through the Wabash Tunnel. One route, 51L, will turn left on East Carson and use Arlington Avenue.
The tunnel work will include replacing tracks, the overhead wire that provides power for the trains, drainage and the tunnel liner.
The project is among a series of upgrades to the light rail system that are expected cost $150 million and take at least three more years to complete. Future work includes a two-year project to rehabilitate the Panhandle Bridge, which carries trains from South Side into Downtown Pittsburgh, at an estimated cost of $68 million.
Ed covers transportation at the Pittsburgh Post-Gazette, but he's currently on strike. Email him at eblazina@unionprogress.com.