Adam and Kay Kidd, of St. Louis, stood staring. First at the "How to Buy a Farecard" chart. Then at the illuminated fare chart. Then at the Farecard vending machines at the Woodley Park-Zoo Metro station.

Their concentrated gazing failed to crack the code. "I have no idea how much it costs," Adam Kidd said on a recent Saturday.

"Can we use one $5 bill to get two cards?" Kay Kidd asked, one of the millions of visitors to the Washington area each year who get to figure out the Metro system for the first time. "I can't wait to see what the rest is like, it's been confusing so far."

The Kidds have company in their confusion, particularly among the non-English-speaking tourists and small-town visitors who are initially baffled by the complexity of Metro's fare system, the process of buying a Farecard and the challenge of choosing which train to take.

As soon as the cherry trees start blooming, those bewildered newcomers start appearing in bigger clusters around the Farecard vending machines, blocking the way of daily commuters who enjoy the convenience that comes from familiarity with the Metro system.

"I'm not used to using public transit. In Tennessee, everybody and their dog has a car," said James Maze, of Knoxville, who was trying to get from Woodley Park to the Smithsonian station. "How do you know how much to spend? Does it cost to change from one train to another?"

One of the biggest complaints is the lack of signs.

For example, Metro does not display Farecard information in any language other than English, despite the large number of foreign visitors attracted to the nation's capital.

"The Metro in New York for us was easier," Andrea Gruber, of Innsbruck, Austria, said in halting English recently after facing the Farecard machines at Union Station. "There you can get a coin in an office . . . . It's not easy here."

Metro officials have debated the question of foreign language signs for years, but have rejected the idea because it would lead to a "proliferation of signs," which would conflict with the system's simple, stark design.

The transit authority publishes brochures in several languages and distributes them through hotels and travel agencies, said spokeswoman Beverly Silverberg. "We do it in some ways, but not in the most convenient way," she said.

Other riders are confused by the signs that they do see. "But we don't want to spend $10," said Sally Alden, of Syracuse, N.Y. Along with other first-time users, she was confused by vending machine signs that offer a 5 percent bonus in Farecard value when the rider puts in $10 or more. Several riders thought that $10 was the cost of a ticket, because that was the only price they saw on the machines.

Some visitors call Metro for advice, only to get incomplete information. Bob Bick, of Shelburne, Vt., said on a recent Sunday that he had called Metro that morning for instructions and was not told the system wouldn't open until 10 a.m. So Bick, his wife and two daughters showed up at a closed station and ended up taking a taxi to the zoo. Bick said, "The rep of the system is great. I suspect it probably is. It's just a problem of getting acclimated."

Once visitors get to the trains, they find it's easy to get lost in the system, even when they have a Washington area resident as a guide.

"I didn't realize we were entering the Orange Line," said George Zahodnick, of Rockville, who was trying to lead nine visitors to Arlington Cemetery, but found himself explaining why they were heading for Vienna instead.

Zahodnick said he couldn't hear the train operator, who had announced that the train was on the Orange Line bound for Vienna.

Zahodnick's friends didn't seem to mind. "The kids love the trains," said Bob Dixon, of Famwood, N.J. "And this is absolutely clean."

"And efficient," said his wife, Ilene. "We just don't know where we're going."