The hub, which will link PATH to the city's downtown subway lines and ferry routes, will feature an oblong glass-and-steel atrium with soaring wings. The atrium's top will be open.
Construction could begin late this year, with part of the station in use in 2006 and completion in 2009. The hub, which will replace the station destroyed in the Sept. 11, 2001, terror attacks, will rise off Church Street, just south of the recently opened temporary PATH station.
Calatrava said the station's wings, which will rise 150 feet, offer a sense of rebirth as well as protection from wind and rain. They will be designed from a security standpoint, including the use of safety glass.
"We will continue like that in order to deliver the most beautiful and safe building," he said.
While reaction to the design was generally favorable, there was some question about the price tag.
"It is expensive, and people have asked, 'Do we really need two transportation centers downtown?'" said Jeremy Soffin, a spokesman for the Regional Plan Association, referring to the proposed Fulton Street subway station nearby. "Sometimes it's worth spending the money to get something iconic."
The RPA strongly backs the projects.
Calatrava's hub was commissioned by the Port Authority of New York and New Jersey, which is financing the project with federal rebuilding funds and insurance proceeds from the terrorist attacks.
Officials defend the costs, saying extraordinary structures will help honor the nearly 3,000 people killed on 9/11.
"I don't think we can afford not to be grand," Mayor Michael Bloomberg said. "What would people say 50, 100 years from now if they look back and thought just because we had a short-term financial problem that we jeopardized our whole future? We simply won't do that."
Daniel Libeskind, the site's master planner, agreed. "Architecture is a key element of human life," he said.
Before 9/11, the PATH station at the World Trade Center was used by more than 65,000 New Jersey commuters each weekday. The Port Authority predicts 250,000 commuters and visitors will use the new station by 2020.