On a normal weekend in Williamsburg, with the L subway line running on schedule, several hundred people might visit artMovingProjects if it has a popular exhibit. But when the L train is shut down, owner Aron Namenwirth said he’s lucky if 10 local artists show up.

But such is life along the L line. For the last three years, the Metropolitan Transportation Authority has been modernizing the line so that it can someday accommodate a higher capacity. In order to do the work, the MTA often shuts down the line on the weekends. Since January 1 of this year, the L line has been closed on four weekends out of nine. It’s a situation that hits Williamsburg art galleries especially hard: Most are only open Friday through Sunday.

A co-owner of Schroeder Romero gallery, which recently packed up and moved to Chelsea, said her gallery was losing about $10,000 a year because of weekend disruptions on the L line when it was located in Williamsburg. The neighborhood is known for its upstart art scene, but the problem also affects the bars, restaurants, and shops that usually do their best business on weekend nights.

The situation is a clear illustration of the power of the subway system in New York City. With a major transportation artery shut down, the influx of people with disposable income necessary to sustain businesses comes to a halt.

MTA officials said they expected to meet their new deadline – June 1 – to complete the changes, but Williamsburg has heard it all before, several residents said. “That’s exactly what they told us last year,” Alun Williams, the owner of Parker’s Box gallery on Grand Street, said.

The L line is in the latter phase of introducing communication-based train control, a system that controls subway trains by radio signal from a central MTA command center. A conductor will still be on the train, but not driving it. The new technology is expected to increase the capacity of the L line by running more trains on the track with less distance between each train. The system is in a test phase: Starting Monday, the test is set to expand to the section of the line to the Third Avenue station from Manhattan’s Eighth Avenue station, a transit authority spokesman, Charles Seaton, said. He said the delays were caused by complications installing the new technology on the tracks. “Like all new technology, you do hit roadblocks,” Mr. Seaton said.

Some gallery owners have reacted to those roadblocks by trying to work within the system. A group of business owners organized themselves with the goal of requesting greater transparency and accountability from the MTA. After meetings with the MTA in 2004 and 2005, many of the most outspoken and active opponents agreed to stop their protests with the assurance that the construction would end in June 2005. By the time the MTA disregarded its deadline, the movement had dwindled to a few disenchanted residents and business owners, Mr. Williams said.

“Someone told me that it’s a bottomless pit that you can pour all your energy into and not get any satisfaction,” the owner of NURTUREart and a longtime advocate for Williamsburg galleries, Karen Marston, said.

Other owners have found the unpredictable subway service reason enough to leave Williamsburg for neighborhoods such as Chelsea. About 10% of the galleries listed in the Williamsburg Gallery Association have left in the past three years, gallery owners estimated.

One of the co-owners of Schroeder Romero, Lisa Schroeder, said there were a number of reasons the gallery made the move to Manhattan, but the L train disruptions was the primary cause.

“If collectors realize the L train is down, they aren’t going to come out,” she said.

One recent subway shutdown was particularly painful for artMovingProjects. An excellent review was published in a local magazine – “which happens once in five years,” Mr. Namenwirth said – but when the weekend came around, the subways were closed and only a few people showed up.

“You can’t imagine how adversely that affected us,” he said. “It destroyed all that work it took to get that [review].”

The most patient of the bunch have decided to wait out what the owner of the Front Room Gallery, Daniel Aycock, characterized as a “dark storm over Williamsburg.” In order to survive – with or without trains – some gallery owners have adapted to the situation. Mr. Namenwirth’s gallery, art-MovingProjects, kept a single show open for a month and a half – something generally unheard of in the gallery scene. “We knew so few people would be coming in,” he said.

Mr. Williams said he has spent a larger amount of his time than previous years trying to get his gallery’s work into art festivals in America and overseas. Last year, he went to five festivals, and this year he is planning on exhibiting at seven, he said.

“We would have done a lot less fairs,” he said. “It’s a huge amount of work trying to get into these fairs.”

Though transit advocates and politicians have taken up the cause, it has amounted to little. Last December, the head of the City Council’s Transportation Committee, John Liu, held a hearing about weekend disruptions on the L and no. 7 lines.

“No one disputes that they should repair the subways,” he told The New York Sun. “But, there is no accountability on the MTA to minimize the number of disruptions … There’s no way for people to give input. In their mind, weekend service is a luxury service, but so many people today rely on weekend service.”

Teresa Toro, the New York director for the Tri-State Transportation Campaign, said that while it’s good to modernize the subway, the problem is the way the MTA is going about it.

“You have to supplement the program with customer service,” she said. “If they are going to be doing this all over the city, they need to have the alternate transportation and communication plans just as in place as the construction.”

Gallery owners are hoping that this weekend’s late-night shows at galleries in conjunction with the Armory Show remind the art-going public that there is still a vibrant – albeit struggling – gallery scene in Williamsburg. Several galleries are open to 11 p.m. on Saturday night and will be exhibiting special shows.

As Ms. Marston from NURTUREart said: “We don’t want people to think we are withering away out here.”