A bridge-resurfacing project threatens to tie up the westbound Schuylkill Expressway in South Philadelphia for much of the weekend.

From 8 p.m. Friday until at least Sunday morning, and possibly until 5 a.m. Monday, only one lane will be open at the University Avenue/Grays Ferry Avenue Interchange (Exit 346B), according to the Pennsylvania Department of Transportation.

Motorists are urged to find alternative routes. Drivers crossing the Walt Whitman Bridge from New Jersey can take I-95 north to I-676 west (the Vine Street Expressway) to meet up with the Schuylkill in Center City. Taking I-95 south to the Blue Route (I-476) is another way to bypass the construction on the way to the western suburbs.

The project involves putting new concrete on two bridges that support the expressway over two streets, railroad tracks, and the Schuylkill. The second lane is expected to reopen Sunday morning or early Sunday afternoon, according to PennDot. Crews, however, could work until 5 a.m. Monday if needed. - Peter Mucha