The North Side has been redesigned. Its main arteries -- Federal and Ohio streets -- are reconnected, and the shadowy, concrete expanse of Allegheny Center sits reformed in the middle of traffic grids, drenched in sunlight and greenery.

Not only that, there are more walking paths, water features, street lights, a theater for all tastes, and coffee shops. And the drippy, pigeon-infested, badly-lit railroad underpass that separates the North Shore from the North Side? Gone.

On the practical side of fantasy, 42 Carnegie Mellon University architecture students redesigned the North Side to the delight of most of the 30 people at an "urban lab" workshop at the Children's Museum Wednesday night. It was the last of three such workshops.

Each fall semester, Carnegie Mellon's fifth-year architecture students focus on a neighborhood, studying its history, identifying its design flaws and social needs, then set about redesigning it. The project helps students develop as designers.

The finished product -- a full-color booklet of all 11 schemes -- needs a funding source.

The final presentation drew more people than the first two, but student Flora Bao expressed regret that more didn't wander in.

"We handed out more than 2,000 fliers," she said. "We wanted to get more people who weren't already plugged in.

"Maybe it's a good thing, though. The people who are here already know these things, and maybe they can make things happen."

"It was energizing for all of us who have been going round and round on these issues for years," said Christina Schmidlapp, leader of the Allegheny Commons Restoration Project. "The students also reinforced ideas the neighborhood has held, that barriers are better off removed, like connecting East and West Ohio streets and upper and lower Federal. It's fun to see such talent trained on our issues with fresh eyes."

Much of the proposed redesign falls into the pipedream category. The railroad isn't likely to remove its overpass. A new pedestrian bridge over Route 279? There's already a chain-link-sided bridge over the rush and roar of traffic now.

But the possibility of public boat slips along the Ohio at Manchester doesn't seem so remote. Neither does a design for better integration of the properties near the 16th Street Bridge that include the Del Monte plant, the Sarah Heinz Home and the Heinz Lofts.

In fact, one idea from a past urban lab has gotten legs in the Hill District.

Kirkpatrick Park doesn't exist yet, but Hill advocates convinced the Community Design Center of Pittsburgh that $12,000 to the nonprofit Find the Rivers! was a good investment toward a larger vision of connecting the Hill to the rivers, said Jason Vrabel of the design center. The project team for Kirkpatrick Park has gotten additional support from the Local Initiative Support Corp. and should soon be ready to show the project plan to funding and other support agencies, he said.

David Lewis established the urban lab at Carnegie Mellon in the 1960s "to include a whole sector of the population that wasn't being heard," Mr. Lewis said. The concept did not take off until he returned from Yale University in the 1990s. Since, he said, "we have worked in 20 communities in the region."

Mr. Lewis said all exciting results start with the excitement of imagining. "We are working with communities and leaving behind a [model] of how things can be done."

Rebecca Davidson-Wagner, director of the Central Northside Neighborhood Council, said one affordable and instantly-transforming idea would be to place murals of cityscape housing along the unfriendly interstate bridge.

"We could do that. There are so many artists over here. Anything to jazz that bridge up would be nice."