Thousands of people arrived late for work yesterday as trains on Metro's Orange and Blue lines were stalled during the rush hour until an ailing woman could be removed from the subway.

The incident marred inauguration of weekday operations of the Orange Line extension from Rosslyn to Ballston in central Arlington and took an inexplicably long time to resolve, Metro officials conceded.

The stricken woman, later released from George Washington University Hospital's emergency room, was noticed to be ill shortly before 8 a.m. on an inbound train approaching the Potomac Avenue station in southeast Washington. She was removed from the train -- eight stations later -- at Metro Center at 8:22 a.m.

Jammed trains on the combined Orange and Blue lines were back up on either side of Metro Center for at least 15 minutes until she was removed from the train.

In addition to that problem, there was the usual first-weekday confusion that occurs whenever Metro changes anything. Metro's train operators and control personnel kept the problems to a minimum with repeated announcements about the new routings for the trains.

The same compliment cannot be paid to the signs on the side of the Blue and Orange line trains, which behaved as they have for the three years Metro has been running those cars. Many of the signs simply did not work. One train pulling into the Pentagon City Station at 7:15 am. did not have a single destination sign in operation.

The first three cars of another train at Foggy Bottom in the evening rush hour gave passengers the following destination choices: "Ballston" (on the Orange LINE), stadium-Armory" (on the Blue Line) and "No Passengers."

For the first rush hour in Metro's history, the signs really mattered, because the opening of the Orange Line extension means that riders boarding Virginia-bound trains can head in two directions after the Rosslyn stop.

A small number of irritated, confused commuters found themselves in the new Arlington Courthouse station on the Orange Line yesterday evening instead on the Blue Line, which would have taken them to the Pentagon and National Airport.

"I always stand at the same place every night and take the same train," said Emma Colucci, a Justice Department secretary who thought she was going to the Pentagon. "I just didn't pay any attention tonight."

John Leonard, an accountant who lives in Burke, said "I knew all about these different lines but the guy announced that anyone who wants to go to National Airport should transfer at Rosslyn. Well I wanted to go to the Pentagon, not National Airport, so I just stayed on the train and ended up here. It's very annoying."

There was also a surprise for people heading toward Stadium-Armory and New Carrollton. Before, all trains went to New Carrollton, Now, Blue Line trains stop at Stadium-Armory. That means that people who catch a Blue Line train but who want to continue to Minnesota Avenue, Deanwood, Cheverly, Landover and New Carrollton must get off their train at Stadium-Armory and wait for the next Orange Line train.

Barbara Francis, of Bowie, said " think it's terrible when you get on the train and you're tired and you want to go home. I heard people talking about it this morning but I didn't understand it." The change, she said, would cause her to miss a bus at New Carrollton and would cost her about 10 minutes.

Metro geneal manager Richard S. Page said yesterday he was concerned about the time it took to get help for the ailing woman. "We've got to work on it."

Delays were cased not only to trains backed up behind the one with the woman, but also to trains running the other direction as Metro attempted to run one-way operations around the Metro Center platform while the woman was treated.

Page also promised that the destinatin signs on the sides of the train would receive increased attention.