It is a quintessential subway platform pose — the slight lean over the edge, peeking to see the light indicating when the next train will arrive. But this weekend, passengers waiting for trains looked not into the tunnel but up in the station, where, for the first time in New York, screens displayed “real time” information about subway train arrival times. The Metropolitan Transportation Authority rolled out the first of its new train-arrival message screens at 14 stations along the L line.

The technology brings New York up to date with cities like Washington, London, and Tokyo, whose subway systems already have train-arrival message boards. But it caused some confusion for New Yorkers over the weekend.

The screens, which display departure times for two scheduled trains in each direction, regularly overestimated the time until a train’s arrival or else announced only a “Delay.” At some stations, the screens were not working at all, and displayed just one generic message: “This is a test. May not be accurate.”

Many riders said they found confusing a series of changing numbers displayed between the destination and minutes until arrival. A New York City Transit spokesman, Paul Fleuranges, said that the inexplicable digits that flash on the screens are “for internal purposes for the test” and are temporary.

Delays have plagued for years the MTA’s plan to bring train-arrival message boards to the subways. The $160.6 million contract to install the screens at 157 stations on the numbered lines was awarded to Siemens in 2003, but technical difficulties held up the project. Mr. Fleuranges said yesterday the train-arrival screens will be “installed in stages over time, with an eventual completion sometime in ’08 or ’09.” That date is for the numbered lines; except for on the L, there is no plan to extend the notification signs to the lettered subway lines, whose nicknames — “Forever” for “F,” “Never” for “N” and “Rarely” for “R” — indicate that such signs might just encourage riders to surface and walk or take a taxi.

Some passengers said that after so many delays, they expected something that looked less drab and provided more information. The MTA is displaying the new messages on old electronic signs that have until now remained blank and gone generally unnoticed by passengers.

“More useful information would be if it told you which train car is less crowded so you would know where to stand on the platform,” a construction worker, Patrick Dub, said while boarding the Manhattan-bound L train at the Lorimer Street stop.

Some riders said that they might use the information about long delays to duck out of the station for smoke breaks, while others said knowing the arrival time only fed their anxieties by making them more aware of how late they might be to work.

The L line, which travels across 14th Street in Manhattan into Williamsburg in Brooklyn, was chosen as the guinea pig for train-arrival screens because it is the only line in the system with Communications Based Train Control, a signal system that gives operators information about train movement and makes train-arrival information possible.

The senior attorney for the Straphangers Campaign, Gene Russianoff, called the new screens “positive” for their ability to reduce passenger anticipation and anxiety on the platforms. “But the displays are kind of the icing on a rotten cake,” Mr. Russianoff said, referring to the technology that makes the displays possible, but will also be used to cut the number of conductors needed on the L line.

Some riders this weekend waxed philosophical about the new information screens. “Seven minutes feels longer when you know from the start it’s going to be seven minutes,” a publicist who lives off of the Bedford Avenue subway stop, Reshma Patel, said.

“If it were conceivable to walk when the wait was going to be long, I might leave,” said a designer, Christian Rudder. “But in Brooklyn, there’s no other option, so what’s the point of even knowing?”

“It’s nice to have the option to know,” said Megan Foley, who works in marketing and lives near the Lorimer Street station. “But is it going to be accurate? That’s the real test.”

The screens will be dark today. “We’re still in a test mode. Should be back by Tuesday,” Mr. Fleuranges said.