Port Authority of Allegheny County closes Saw Mill Run Boulevard Bridge

Port Authority of Allegheny County closes Saw Mill Run Boulevard Bridge.

Port Authority of Allegheny County

A Port Authority-owned and maintained bridge that carries the South Busway over Saw Mill Run Boulevard in Pittsburgh's Mt. Washington neighborhood will remain closed indefinitely. Engineers on Friday discovered that a portion of the bridge had shifted.

The Saw Mill Run Boulevard Bridge — sometimes known as the Palm Garden Bridge — a 1,052-foot span constructed in 1977 that is used only by Port Authority buses and light rail vehicles, is stable but will remain closed until repairs can be made. Following the bridge’s last inspection in October 2020, it was rated Satisfactory (6). 

Port Authority, in coordination with third-party contractors, is developing a timetable for repairs. The cause of the shift has not been determined. 

At about 9 a.m. on Friday, a Port Authority employee noticed that a joint on the deck of the bridge appeared to have expanded. 

Port Authority suspended bus and rail traffic immediately, and dispatched engineers and a bridge consultant to begin examining and surveying the joint for signs of distress and movement. 

Engineers determined that the bridge is stable, but that it must be repaired before it is used. Therefore, Port Authority and contractors will soon begin to mobilize to make the necessary repairs. 

The work will consist of removing a portion of the concrete bridge deck to access the bridge’s superstructure; removing the existing anchor bolts and resetting the position of the bridge; repairing and/or replacing the rail joint; and replacing the portion of the concrete deck that they remove. 

Because of the nature of the work, Port Authority crews will also need to make sure the overhead power lines are removed before construction begins and replaced once construction is completed.

Red Line rail cars will detour via the Blue/Silver Line from Overbrook Junction to Downtown. A rail shuttle will operate between Overbrook Junction to Potomac Station. Bus shuttles will operate between Potomac Station and Station Square.

Bus detours are still being finalized and will be posted on Port Authority’s website and social media channels as soon as they are complete.