"Brilliant."

That's how Heidi Zimmer-Meyer, president of the Rochester Downtown Development Corporation, describes the preliminary design for the most controversial part of Renaissance Square: the bus terminal.

Architect Moshe Safdie unveiled his concept for Ren Square at a public forum last week. And while this stage really is "concept," not completed design, there was major news: Safdie and his design team have scrapped the idea of an underground terminal.

In its stead, they proposed a street-level bus station, running east to west along the project's northern edge, about where Mortimer Street is now. With the change, they not only dealt with one of the biggest objections to Ren Square, but they made substantial practical gains. They reduced the terminal's size by about 100,000 square feet, saving about $30 million. And they made it much easier for buses to navigate the terminal, cutting costs and emissions.

Ren Square will occupy a large, crucial city block, bounded by Main Street on the south, Clinton Avenue on the east, what is now Mortimer Street on the north, and St. Paul Street on the west. Safdie's concept is for a completely integrated complex, with MonroeCommunity College's downtown campus on the west, a public concourse with retail stores in the center, a performing arts center on the east, and the transit center behind them.

Most structures in that area would be demolished for the Ren Square components, but in Safdie's plan three architecturally significant buildings --- the GraniteBuilding on Main Street and the Edwards and CoxBuildings on St. Paul --- would remain and could be incorporated into the MCC campus.

Safdie has also addressed the concerns that had sent the bus station underground in the first place: that noise and emissions would dampen enthusiasm for redevelopment north of the project, particularly housing. Safdie has enclosed the station, and he put a tree-lined park above part of it, one story up from the street.

And to address concerns that an enclosed terminal would be oppressively dark and awash in the fumes of idling buses, Safdie and his designers added two more features. A low arcing glass roof slices lengthwise through the park, letting natural light into the terminal below. And glass walls separate a climate-controlled waiting area from the buses themselves.

Still, while the design solves some of the project's problems, there are plenty of other decisions to be grappled with. Most of those revolve in some way around the effect Ren Square will have on downtown. Predictably, its backers have played up the project's potential economic benefits, often in the rosiest of terms. Here's a sample from the project's web site: "Creating a destination in our city center will bring people from all over to downtown Rochester."

But the success of Ren Square hinges on solving a classic chicken-and-egg dilemma. The novelty of a Safdie gem downtown will almost certainly lure plenty of visitors once, but there'll have to be something --- restaurants or retail, for instance --- to keep them coming back. Yet without a critical mass of patrons in place, it'll be risky for businesses to open there. And while market-rate housing is growing downtown, it's growing slowly.

At the Wednesday forum where the designs were unveiled, RGRTA Chief Mark Aesch suggested that current bus riders, an estimated 25,000 of whom transfer downtown every weekday, might provide that critical mass at first. But their presence hasn't bolstered retail in the Main and Clinton area. One reason, which no one seems to want to acknowledge, is that many RTS bus riders simply won't have enough disposable income to be attractive to many retailers. Expecting the city's working poor to underwrite downtown's recovery seems a losing proposition.

The other two components represent possible solutions. The first is the expanded MonroeCommunity College downtown campus. MCC plans to offer more courses in health care and technology in the new facility. And the number of students will grow, says MCC President Thomas Flynn, from the current 2,000 or 3,000 to 5,000.

Ren Square's performing arts center would also draw people downtown, many of them willing and able to spend money on dinner before a show or drinks afterward. It could help make that area of downtown an evening destination.

But of all the components, the performing arts center is most in limbo. It's the least fleshed out component in Safdie's preliminary design. Even the number of theaters is still up in the air. That's at least in part because Safdie's team is awaiting the results of an Arts and Cultural Council study, says Renaissance Square Project Manager Mark Ballerstein.

In addition, little funding has been lined up yet for the arts center, and a significant amount (about a third, says Ballerstein) will have to come from private donors. And even a steady stream of events wouldn't necessarily attract enough people to support many spin-off businesses.

So will adding theater-goers to the mix change things enough to spur development?

"No, not alone," says Heidi Zimmer-Meyer. The hope that Ren Square offers, she says, is that the sum will be greater than the whole of its parts. A signature piece of architecture downtown can't magically conjure up crowds of pedestrians, but the excitement and energy it brings to the area could attract the mix of businesses that might.

In fact, in many ways the success of Renaissance Square will be judged finally by everything not directly related to the project itself. The rubric will be what happens around it. Will it turn the area around? Some of the early signs are encouraging. To begin with, there's the park that doubles as the bus station's roof. That space engages the buildings to the north of the site.

"That's critical," says Zimmer-Meyer, particularly if those buildings are going to be used for housing. "It's now much more appealing" than in previous plans, she says. Zimmer-Meyer likens the atmosphere created by placing the park near potential housing to that of a large central courtyard surrounded by apartments, an arrangement more typical of large, established urban areas.

Another Safdie proposal with the potential for substantial impact outside of Ren Square: Restoring two-way traffic to St. Paul Street and North Clinton Avenue. For the project, that would have the immediate effect of reducing driving distance for eastbound buses. (As the traffic situation exists now, they'd have to make a loop of left turns to enter and leave the facility).

But making St. Paul and Clinton two-way could also have even bigger --- if somewhat less quantifiable --- effects, Zimmer-Meyer and City Councilmember Bill Pritchard say. Both are longtime advocates of making many of downtown's one-way streets two-way.

"It'll foster better neighborhood and community on St. Paul," says Pritchard. One reason, he says, is that it will slow traffic down. If downtown is to be a neighborhood, "you've got to get rid of these mini-highways cutting through it," he says.

Slower traffic would make the area seem more walkable and enhance what Pritchard refers to as the "touchy-feely" elements of the streetscape, the perceptions that pedestrians have.

"They matter when you're developing the neighborhood," he says.

And Zimmer-Meyer says changes prompted by Ren Square might spark discussion about changing one-way streets to two elsewhere downtown.

"I'd be disappointed if there isn't more talk about it," she says.

(Calls to city traffic engineers --- who've opposed such changes in the past --- weren't immediately returned.)

Finally, there's the connection between Renaissance Square and other nearby points of activity. More than once during his presentation last week, Safdie interrupted himself to encourage the audience to push for such links. Connecting the project to the river --- just a block away --- is vital for downtown, he said. So is connecting it to whatever becomes of MidtownPlaza. Safdie's designs even included details like new tree plantings that suggest such connections.

If that vision comes about, the streetscape could be so transformed that visitors will park their cars in the East End and walk along Main Street through a thriving downtown to the river, says Zimmer-Meyer.

"Right now you wouldn't do that," she says, "but five years from now, I think that'll change."