Mr. Roberts said his interest was based on simple economics. Double-deckers can carry about as many people as the longer bus that the transit agency now uses, according to Joseph Smith, senior vice president for the agency’s bus operations. But they cost less to maintain because they lack the complicated connector and accordion apparatus that links the two portions of an articulated bus.

Those who rode the double-deckers in their heyday have fond memories.

“Back in the days when money was important, it was great to take a date out and you could have a nice ride up and a nice ride back on a summer evening,” said William J. Ronan, 95, who first rode the buses when he came to New York during his student days in the 1930s (three decades later, he became the first chairman of the Metropolitan Transportation Authority).

“It was sort of a genteel way to travel and perfectly respectable,” he said. “Between that and the Staten Island Ferry you could have a wonderful date.”

Mr. Ronan said the seats in front on the upper deck were considered the best ones. “You tried to get up in the front seats, which were great because you had the view up the avenue,” he said.

. . .

Mr. Ronan tried to bring the double-decker buses back in 1976, when the transportation authority bought eight of them from a British company to be used in a pilot program. [Transit spokesman Charles F.] Seaton said the buses had mechanical problems and were off the road after about two years.

But there were other problems, including on the continuation of some Fifth Avenue routes where the buses travel along Riverside Drive.

. . .

The New York Times spent months examining the system, the money spent on it and the oversight by management — conducting dozens of interviews and reviewing thousands of pages of documents. Through an analysis of more than 10 years of records not previously released by the transit agency, reporters were able to track breakdowns, repair calls and maintenance for every escalator and elevator in the system.

What emerged was a portrait of startling shortcomings.

The more than 200 mechanics who maintain and repair the subway’s elevators and escalators receive as little as four weeks of training, a fraction of what they would receive in other transit systems or in private industry. And transit officials concede the system is so inefficient that many elevator and escalator mechanics spend barely half of their shifts actually working on troubled machines.

Managers often rush balky elevators and escalators back into service without identifying the underlying causes of mechanical problems, leading to more breakdowns.

Many problems occur because of basic design flaws or mistakes made during the construction of the machines, when contractors worked with little or no oversight. Those conditions left many of the machines virtually broken from the outset.

“They don’t have enough competent people with the proper training,” said Michele O’Toole, the president of J. Martin Associates, which the transit agency hired in 2006 to evaluate its elevator operations. “It all reflects back to qualifications, training, capabilities.”

Transit officials say the subway presents unique challenges.

Highlighting the transportation improvements arranged specifically for the new IKEA is free water-taxi service to and from lower Manhattan.

The service, to be provided by New York Water Taxi, will run every 40 minutes during store hours, said store manager Mike Baker. Water taxis will dock along a 6.5-acre public esplanade that IKEA had to build behind the store to help garner elected officials’ support for the controversial $100 million project.

Other transit improvements will include beefed-up bus service and free shuttle service connecting to the three closest subway stops, which are still over a mile away.

. . .

Red Hook itself is fenced off from the rest of the borough by the Brooklyn Battery Tunnel and Brooklyn-Queens Expressway, and even the nearest highway entrance on the BQE is over a mile away from the 346,000-square-foot store.

IKEA is offering 1,400 parking spots, although the project’s environmental impact statement estimates about 14,000 cars arriving on Saturdays. [Red Hook Civic Alliance co-chair John] McGettrick says he believes it will actually be 20,000.

But IKEA spokesman Joseph Roth said he expects most New Yorkers to leave their cars home and use the new transit options.

For example, IKEA is offering free shuttle service every ten minutes from three subway stations: Borough Hall/Court Street in Downtown Brooklyn, Smith/9th Street in Carroll Gardens, and 4th Avenue/9th Street in Gowanus.

There is no view to admire. The trains are still well below street level, on tracks running within a box-shaped concrete tunnel that bisects the World Trade Center site. But instead of soil, the south half of that 975-foot stretch of subway rests on a newly built network of brawny steel beams atop a forest of minipiles reaching down to bedrock.

And in recent weeks, workers have dug out so much soil from around those minipiles that they have created an underpass beneath the subway large enough for construction machinery to pass through. In the reconstruction of the trade center, it is a significant milestone of east meeting west.

Gradually, the entire volume under the subway box will be cleared of soil, until the section from Liberty to Vesey Streets is structurally more like a viaduct than a tunnel.

That will open up nearly 40 feet of vertical space under the tracks. And given how many purposes the site must serve, every cubic inch is precious.

In recent months, two full-size mock-ups of a few floors of the glass and aluminum facade have been built and tested. One is outside Los Angeles, in Ontario, Calif. The other was at a site in central New Mexico that can be reached only over dirt roads in four-wheel-drive vehicles.

At 1,368 feet, with 23 acres of glass-clad surface area, 1 World Trade Center will be subject to tremendous natural forces. The building, also known as the Freedom Tower (at a symbolic 1,776 feet, when its mast is counted), will be the tallest in New York City and as the skyscraping phoenix on the site of ground zero, it may be the target of terrorist attacks, too.

The Port Authority of New York and New Jersey, which is building 1 World Trade Center, and Skidmore, Owings & Merrill, which designed it, said both mock-ups performed well. The facade, called a curtain wall, is being made by Benson Industries of Portland, Ore. The engineering firm Weidlinger Associates is the consultant in blast-resistant design.

“Physical testing is a confirmation that curtain-wall contractors are in fact meeting performance requirements,” said Carl Galioto, a Skidmore partner. “Full fabrication of the curtain wall cannot begin until the mock-up specimen passes these tests.”

. . .

The first mock-up was subjected to a blast test in Socorro, N.M., at the Energetic Materials Research and Testing Center, a division of the New Mexico Institute of Mining and Technology. Because details might arm a prospective attacker — providing information like how much force the curtain wall is designed to withstand — officials would say almost nothing about the test of this mock-up.