Even as thousands of people commute to Woodbury every day to work in Gloucester County's administrative offices and Underwood-Memorial Hospital, the city faces a vexing problem: They don't stay past 5 o'clock.

Lacking customers, Woodbury, population 10,174, is losing retail to nearby towns with big malls such as Deptford and Cherry Hill. Even among the businesses that line the city's main street, turnover is high.

City officials are working in earnest to revitalize downtown. In 2009, City Council designated the downtown business district as an area in need of redevelopment, and officials adopted a long-term strategy soon after.

They aren't the only ones brainstorming fresh ideas for Broad Street. In January, as part of a first-year workshop, a team of eight graduate students at the University of Pennsylvania School of Design began to draft a plan to revitalize Woodbury.

As part of the process, they interviewed city officials who are now interested in the final product, completed in late April.

Penn students in the class studied six other regional towns, "most of which have nice traditional downtown areas but all of which need some updating," said John Landis, chair of the department of city and regional planning at PennDesign. "They're losing their economic base, or retail base, or the core areas are getting a little old and need a little reinvestment."

The team studying Woodbury learned two startling facts: Woodbury residents spend $44.7 million more at retail stores outside the city than they do in the city, and 20 percent of the stores on Broad Street are vacant.

"That was pretty shocking to see," Melissa Andrews, a first-year student at PennDesign, said on a recent morning while walking along Broad.

In general, the students recommend that the city take steps to make it more pedestrian-friendly; use transportation services to better connect residents to downtown; and support new businesses.

The students identified a "physical, economic, and activity gap" separating North Broad, anchored by the hospital, and South Broad, which features administrative buildings and the city's commercial core.

"If you're by the hospital, you see a hill and a bunch of law offices, not the center of town," Penn student Fritz Ohrenschall said.

So he and his team proposed the development of a visitor's cafe next to Woodbury Creek, where hospital workers and others could get a cup of coffee. The space is currently occupied by the police station parking lot.

The plan also calls for a restaurant and river walk overlooking the creek on the other side.

Even if workers don't make the trek up to the main business corridor, simply "getting people out of their offices is good for the tax base," Ohrenschall said.

Small quality-of-life amenities such as benches could make the walk more inviting, the group says, and a bike-share program could provide an incentive to eat lunch on South Broad.

To improve retail, the students recommend the creation of a business improvement center to provide training. The city could require businesses to participate in the program to receive funding from the existing Woodbury Business Assistance Loan program.

City officials acknowledge the challenges they face in creating a vibrant downtown.

"We're like many communities struggling to keep occupancy high and to fill locations where we've got, in some cases, stores that haven't been occupied for some time," City Council President William Fleming said, adding that the city intends to review the Penn students' report.

"The big retailers there in the '70s for the most part were displaced by Deptford Mall, and some of the other big-box kind of development around us makes it tough for the smaller retail establishments to take hold," he said. "That's probably, in the global sense, the biggest issue we're facing."

Instead of trying to compete with the malls, Fleming said, Woodbury is trying to attract restaurants and retailers that will fill a niche in the community.

He said the city had made incremental steps: Broad Street was reduced from four lanes to three last year, increasing foot traffic; a mixed-use building for senior living and retail is under construction; and a Bottom Dollar Food grocery store is scheduled to open sometime this summer.

The city is hopeful that a proposed $1.5 billion regional rail line to Camden will create more market demand for nearby retail. Neither the Delaware River Port Authority nor NJ Transit has committed to funding the light-rail line, however.

"We've got a pretty good start on things," Fleming said. "We're going to have to work through what the economy will give us."