Harried commuters are braced for protracted delays as the long-awaited reconstruction of the South Street Bridge begins tomorrow, closing the historic span over the Schuylkill and necessitating detours expected to last two years.

The 23,000 motorists and countless pedestrians and bicyclists who rely on the bridge daily to go between University City and Southwest Center City will have to use alternate routes because the 85-year-old bridge is "structurally deficient," inspectors say, and must be demolished and rebuilt.

"Significant traffic congestion and travel delays are expected," Streets Commissioner Clarena Tolson said of the $67 million project. "We ask Philadelphians for their understanding."

The reconstruction will affect staff and patients at the Hospital of the University of Pennsylvania, the bustling complex near the bridge's west end, said Kevin Mahoney, senior vice president of the Penn Health System.

Staff are encouraged to use public transportation or to carpool, he said. Those who walked to work across the South Street Bridge will likely cross on the Walnut Street Bridge, Mahoney said, "adding some time to their commute. But we are hoping they stay on foot because we certainly don't want more cars over here."

Penn has installed more bicycle racks and added runs for its local shuttles. Doctors holding monthly parking passes have been encouraged to give those up and carpool or take public transit in exchange for guaranteed parking on the four or five nights a month they are on call.

HUP also has budgeted a large amount of overtime for Penn police to direct traffic at 19 key intersections, Mahoney said. From a command center on campus, the flow of cars will be monitored by closed-circuit television. A city traffic engineer will be on hand to order changes in the timing of stoplights and other adjustments as needed.

For simplicity, Mahoney said, patients arriving by car are encouraged to use University Avenue. The University City SEPTA station near the west end of the bridge will remain open, but the South Street entrance will be closed; passengers will have to enter from Convention Avenue.

East of the bridge, at Ants Pants Cafe in the 2200 block of South Street, co-owner Nancy Silverman said she expected some fall-off in business.

"Some of my regular coffee customers in the morning say they won't be seeing us for a while," said Silverman, whose patrons include neighborhood people and scrubs-wearing doctors and nurses en route to HUP.

Replacing the crumbling bridge "certainly makes sense," she said. "It's just a shame they have to close it to fix it."

Across South Street from Ants Pants, Lee Rogers, owner of Bicycle Therapy, said he was upset that the span had to close at the height of holiday shopping.

"Closing a major thoroughfare before the holidays is stupid," he said. "There's just no other way to put it."

Rogers said he had complained to staffers in the office of his district's councilwoman, Anna Verna, but had been told that a last-minute postponement was not possible.

Now he just hopes that some pedestrians - faced with longer commutes - will purchase bikes at his shop.

The bridge crosses the Schuylkill Expressway and several railway lines in addition to leaping 300 feet across the river. Its closing requires the shutdown of the South Street expressway exit, which serves much of Center City and West Philadelphia.

Parts of the bridge were built for the 1876 Centennial celebration; it was reconstructed in 1922. Although it had shed chunks of masonry for years, safety concerns heightened last year after dozens of cars plunged into the Mississippi River when a Minneapolis bridge collapsed, killing 13 people and injuring 145.

Alternate Routes

South Street

The main detours will route traffic across the river via Chestnut and Walnut Streets.

From the east: Take South Street to 22d Street to Walnut Street to 34th Street to Spruce Street.

From the west: Take Spruce Street to 33d Street to Chestnut Street to 23d Street to South.

Schuylkill Expressway (I-76)

Eastbound traffic headed to east of the river: Take I-676 (Vine Street Expressway) east to 23d Street to South Street.

Eastbound traffic headed to west of the river: Take the 30th Street Station exit to Market Street to 34th Street to Spruce Street.

Westbound traffic headed to east of the river: Take the 30th Street Station exit to Chestnut Street to 23d Street to South Street.

Westbound traffic headed to west of the river: Take the 30th Street Station exit to Market Street to 34th Street to Spruce Street.

SEPTA buses

SEPTA has worked with Grays Ferry and University City community groups to enhance peak-hour Route 12 service to help those neighborhoods most affected by the reconstruction. In addition, because of weight limits on the Chestnut Street Bridge, SEPTA stops at 30th and Chestnut Streets, Schuylkill Avenue (29th Street), and 24th and Chestnut Streets for Routes 12, 21, 40 and 42 have been discontinued until further notice.

For additional information, call SEPTA customer service at 215-580-7800 or visit the SEPTA Web site at www.septa.org

SOURCE: Philadelphia Streets Department; SEPTAEndText

Contact staff writer Michael Matza at 215-854-2541 or mmatza@phillynews.com.