Port Authority officials on Thursday approved a $2.2 billion plan for a new transportation hub at the World Trade Center site.
The hub, slightly modified to reduce its vulnerability to a terrorist attack, is now on track for a Sept. 6 groundbreaking, with a projected opening date of December 2009.
"Lower Manhattan never had a terminal like we are going to build right now," Port Authority Vice Chairman Charles A. Gargano said of the transit hub, which will serve as a terminal for PATH trains from New Jersey, with connections to subways and ferry terminals.
The hub also will be the gateway to the towers, memorial and cultural center planned for the 16-acre Ground Zero site.
Port Authority officials hailed the 210-foot-high main hall as the Grand Central Terminal of lower Manhattan. But the design by Spanish-born architect Santiago Calatrava, who said he was inspired by an image of a bird in flight, is unlike the more traditional terminals and concourses of New York's past.
The airy hall, with walls of narrow white-steel columns and glass, is topped by two wings of steel spires.
On sunny days and on each anniversary of the Sept. 11 attacks, the wings, powered by hydraulics, will lower, enlarging by as much as 30 feet a wedge of light at the arched ceiling of the transit hall.
With requests by New York officials to bring light into the station's corridors, Calatrava said he has worked to make the structure as transparent as possible, enhanced by glass strips in the floor of the main hall and in the plaza floor outside the hub.
But after vetting from city police officials, security consultants and Port Authority planners, the design has evolved somewhat into a bulkier, more reinforced version of the hub that Calatrava unveiled in January 2004.
Glass that was to have been a skin between steel wing spires has been removed and the number of steel columns has been doubled. The length of the street-level structure has been slightly shortened to allow for a greater setback from traffic. And the building's entrance has been bulked up and now includes a beak-like feature protruding from the main entrance.
"It was a very beautifully challenging exercise," Calatrava said of the 18-month evolution of his design.
Even with the changes, the architect said the core of his vision remains in place.
Port Authority officials agreed, saying the hub will become the lifeblood of a revitalized lower Manhattan.
"We set out to accomplish two very specific things," said Port Authority Chairman Anthony Coscia. "First, to build something that had an iconic or memorial element to it that recognized the fact that these are 16 very special acres on this planet. Secondly, we felt it was our responsibility to build something that would restore lower Manhattan as a central business district."
A little more than $1.9 billion of the transit center's budget will be funded by the federal government, which has committed more than $4 billion toward rebuilding lower Manhattan. The Port Authority will contribute about $300,000.
Rebuilding the destroyed PATH station that served the World Trade Center has been the Port Authority's main priority since 9/11. Two years after the attacks, the bi-state agency opened a temporary station at the site, which is now used by about 41,000 passengers a day.
Port Authority officials estimate that more than 80,000 passengers will eventually use the permanent station, and officials said Thursday that forecasts show it will be used by more than 250,000 people a day by 2025.
The agency has not yet chosen a firm to build the project, but said it hopes to do so next month, leading to the construction kickoff in September. The first task will be constructing a temporary track and an additional platform to keep PATH service moving during construction.