The first target of scaled back revisions at the World Trade site appears to be the Santiago Calatrava-designed PATH transportation hub.

This morning the executive director of the Port Authority of New York and New Jersey, Christopher Ward, announced that the station would not maintain the function that would allow the winged like structure to open its roof to the open sky.

“We are not going to build that in such a way that it was originally envisioned — that it would open. It allows us to build the station sooner and it will also save us money. Mainly it will keep that beautiful structure in tact,” Mr. Ward told reporters at a breakfast at Lower Manhattan this morning. “This is the kind of tough decision that we will face.”

Yesterday Mr. Ward presented the first of several assessments of the World Trade Center site but did not disclose any target completion dates or costs. He said an accurate scheduling assessment is impossible due to at least 15 unresolved decisions involving, among others, the design alternatives for the transportation hub.

Mr. Ward did not say exactly how much removing the open-air functionality of the PATH transportation hub would save, nor would he say when he thinks it could be completed.

The PATH station was budgeted at $2.5 billion but recent cost estimates had driven up the price tag by at least $1 billion. From its conception, the PATH station, a white, glass above ground structure designed to resemble a dove, was viewed with skepticism. Some had questioned the logic of moving forward with both the Port Authority’s PATH station and the Metropolitan Transportation Authority’s Fulton Street Transit Center, which would be built within blocks of each other at a combined cost of more than $3.5 billion.

The present, temporary station services about 50,000 commuters daily, most of whom travel back and forth between Lower Manhattan and New Jersey.

By comparison, Penn Station is said to be the busiest train station in America and serves about 600,000 daily commuters from New Jersey and Long Island, in addition to tens of thousands of Amtrak passengers.

Mr. Ward defended the design.

“This is a transportation hub, one of the most beautiful architectural structure that this town will have and making sure we build it and build it right is not taking too long it is doing the right thing to making sure we have what we planned for all of New York.”

Mr. Ward said he expected that additional costs would be shared by all the partners and stakeholders and that the steering committee that he called for yesterday would have the final say on major decisions at the site.

He said that while the World Trade Center Memorial would not be completed in time for the 10th anniversary of the terrorist attacks, he hoped that there would be access to the plaza for a significant gathering and that the pools and waterfalls would be functioning at that time.

Appointed by Governor Paterson in April, Mr. Ward was asked if he felt that the holdovers at the Port Authority were up to the task of getting the project completed. “The mistake isn’t the people that were here, the mistake isn’t what we are doing, the mistake is unfortunately is a set of dates and an end game that you just cannot get to,” he said.

In his report delivered yesterday, Mr. Ward said an accurate scheduling assessment is impossible due to at least 15 unresolved decisions involving, among others, the design alternatives for the transportation hub; the demolition of the former Deutsche Bank Building at 130 Liberty St.; a land deal with St. Nicholas Greek Orthodox Church, and construction concerns related to the suspended parts of the No. 1 subway line, which divides the site.

Mr. Ward said he would be providing an assessment that includes dates and possible budget overruns by the end of September.

The report notes that since 2003 — when the conceptual planning phase of the program was ongoing — construction costs have increased by more than 30%, suggesting steep increases in the projected cost.

Mr. Ward faulted a lack of an “efficient overall decision making process or steering committee” for the delays, which have now spanned the governorships of George Pataki, Eliot Spitzer, and David Paterson.

The candor of Mr. Ward’s report was widely applauded.

“I have a little bit of sympathy,” Mayor Bloomberg said at a press conference yesterday. “The cost of steel and cement and labor has gone up faster than anybody had anticipated, and I think the realities of trying to build multilevel, multifaceted, multiagency projects at the same time is daunting.”

“We are not going to give phony dates or timetables and then follow up with phony ribbon cuttings,” Governor Paterson said at a press conference yesterday.

The speaker of the Assembly, Sheldon Silver, whose district includes Lower Manhattan, said in a statement that he was “pleased” with the preliminary report, but he faulted the Pataki administration for setting unrealistic deadlines.

“The report verifies what I have been warning for years: that the deadlines and estimates originally pronounced by the Pataki administration were never achievable and that the biggest obstacle to reconstruction was and is the inability of the city and the state to provide the unified and focused leadership necessary,” he said.

In a statement, the developer of the site, Larry Silverstein, said progress on towers 2, 3, and 4 is on schedule. “New Yorkers are entitled to an aggressive, reliable schedule for rebuilding the World Trade Center, backed by absolute accountability from the people responsible for getting the job done. Governor Paterson and Chris Ward have shown real leadership in committing to candidly and openly address the challenges,” he said.