The South Street Bridge was closed in December 2008 after years of decay.
Crumbling concrete from the bridge had been falling into the Schuylkill River for years, so the Pennsylvania Department of Transportation decided to tear it down and build a new one.
Since then, motorists have had to use other routes to get from downtown to West Philadelphia - home of the University of Pennsylvania and Drexel University.
Mayor Michael Nutter says the project has been completed a month early and on budget and the bridge will reopen Saturday.
Federal funds accounted for about 80 percent of the cost, with 15 percent coming from the state and 5 percent from the city.