Anyone who has waited at the Dallas-Fort Worth Airport for the automated shuttle train in a remote parking lot 10 minutes from a scheduled flight takeoff has felt a curious rush of adrenaline or panic.

By the time such a visitor scurries through the maze of signs, lines and ticketing procedures, he likely is at the brink of nervous collapse.

But he is one of the lucky ones.

Each year, countless visitors to the nation's largest airport collapse under the stress of travel - some so severely that they are taken to nearby hospitals for psychiatric evaluation.

D-FW drives them crazy.

Airport officials are somewhat baffled about what causes the emotional breakdowns, although it's believed they primarily are related to coping with travel in general and the airport in specific. As many as 20 to 30 people each year are involuntarily committed for psychiatric examination in Fort Worth or Dallas hospitals because of their erratic behavior at D-FW. A great number more appear to be suffering a nervous breakdown.

"For some reason, they come here and something sets them off. In a large institution such as this, you have to make so many decisions and sometimes it just sets them off," explained Karen Collins, who heads the Airport Community Services agency.

"It's usually because something in their plans has gone wrong. They've missed a connecting flight and that upsets them, or they've lost a ticket," she said.

For example, she said, a professor at a large university recently attended a seminar in Dallas and for some unknown reason drifted into senselessness as he stood in line ready to board his flight.

"He was talking to himself," Collins said. When police officers noticed that the man seemd disoriented, a Community Services worker was summoned.

"He was talking outer space and rattling off all these mathematic equations," she said. When he was taken into a private office for questioning, he started to disrobe and became delirious.

But the professor snapped back into reality long enough for the worker to learn his name and call his family. His wife later confided that her husband had been under tremendous stress in recent months, but had no history of mental illness.

"Most of our emotionally disturbed people are highly intelligent and well-read," Collins noted.

"You have to read, think and do so much at the same time" to get through the airport, she pointed out. "The added stress of traveling on top of personal problems is sometimes just too much for some people."

In addition to the weary travelers, many of the people detained for psychiatric evaluation turn out to be local residents who are inexplicably drawn to the airport.

"It's open all night and a lot of people just end up out here. Normally they just want to be around people. A lot of what they are seeking is just someone to talk to," she said.

Airport Police Chief Tom Shehan agrees. "We seem to have more than our share" of mental cases, he said. "The airport seems to be a location where a lot of mentally disturbed people like to gather."

Shehan said the persons who are involuntarily committed are the ones who appear to be a threat to themselves or others because of strange actions - walking on a runway, for instance.

"This guy jumped a fence and ran out onto an active runway. By the time we caught up with him, he was a blithering idiot. He didn't know where he was, what he was doing there, or even what his name was," he said.

The most common symptom of the mentally disturbed people, Collins said, is talking to themselves, or rambling incoherently to others. CAPTION: Picture, The Dallas-Fort Worth airport is so vast that automated Airtrans shuttles are used to carry passengers from one airline's terminal to another, or to main building. AP