PennDOT spokesman Brad Rudolph said crews have reached a critical stage of the project with repairs set to begin on steel beams holding the bridge up and re-decking the bridge surface.
"It's been closed since last summer in August to through traffic for vehicles, but pedestrians and bicyclists could still use it. Beginning Monday, that will no longer be the case so there will be several detours in place," he announced.
The detours include Market Street, Walnut Street or John F. Kennedy Boulevard to enter the city from the west.
The bridge spanning the Schuylkill river is 63 years old, Rudolph said, and is a key connector for eastbound traffic heading from University City into Center City.
"It carries a lot of pedestrians, it carries a lot of cyclists. So we're making some major improvements, lighting improvements," he explained.
According to Rudolph, the bridge carries an average of more than 18,600 vehicles a day.
Besides the bridge itself, the project includes improvements underneath the span including work on the Schuylkill River trail head, a dedicated bicycle lane, and improvements to sidewalks above and below.
Rudolph said crews hope to finish the work and re-open the bridge by late fall.