For Fliers, Mixing Up La Guardia and J.F.K. LIKE many an early morning traveler, Seth Bohart was a little bleary-eyed behind his sunglasses as he prepared to enter the sullen bustle of La Guardia Airport. A frequent traveler who lives in Hong Kong, he was braced for the many familiar hassles of modern air travel: waiting in the ticket line, kicking off his shoes for the security screening, the potential of a delayed or canceled flight, airport food. But moments after he got out of his taxi on a recent morning, the skycaps at the curb refused to take his bags, and instead urged him into a second waiting taxi, post haste. Mr. Bohart discovered that he was experiencing a travel nightmare of a different sort. "How far is J.F.K. from La Guardia?" he asked. Seated in the back of the cab hurtling down the Van Wyck Expressway, with a reporter in tow, Mr. Bohart, 36, alternately blamed a lack of coffee, jet-lag and a late night out with friends for why he misread his itinerary and arrived at La Guardia only to make a mad dash for Kennedy Airport, where his flight was scheduled to take off. The cabby, Mostapha Idly, who races this route with harried passengers almost weekly, marveled at his passenger's poise: "Usually they're like: "Oh my God! Why did I do this? Why did I do that?" " (In response, Mr. Bohart briefly broke his perhaps-studied calm: "Mostapha is making me feel better about myself," he said from the back seat.) Airline workers, tourists and local residents alike make the error. And as the summer travel season reaches its peak, it can be a daily occurrence, according to cabdrivers, skycaps and airline representatives. Some say it is so common that they can recognize a mix-up has occurred from just the first flickers of dismay flashing across a passenger's face. Passengers, that is, who have just realized they are many highway miles from the departure gate. With three major airports less than 20 miles from Midtown Manhattan, New York is one of a small number of cities around the world - like Houston, London, Los Angeles, Miami and Paris - where travelers can find themselves trying to check in at the wrong airport. Visitors who come to New York from one-airport towns are sometimes tripped up by the fact that La Guardia, Kennedy and Newark Liberty International Airport form their own kind of Bermuda Triangle. "People get in the car and say, "I want to go to the airport, New York Airport," " said Shoeb Howlader, 50, a yellow cabdriver. "What's "New York Airport"?" The error is so fundamental a part of New York lore it is a pop-culture staple: George Costanza and Cosmo Kramer spent an episode of "Seinfeld" racing from wrong airport to wrong airport, and in the series finale of "Friends," Ross Geller chased his love to one terminal while she prepared to leave from an airport miles away, though it all came out right in the end. Even usually organized travelers fall victim. Colleen Ritzau Leth, 26, an art curator who lives in Manhattan, prints out meticulously devised travel itineraries detailing each leg of the journey complete with contact numbers and even the daily weather forecast, neatly bundled in binders. "And yet I've gone to the wrong airport three or four times," she said. Jeff Pharr, a spokesman for the Association of Professional Flight Attendants, which represents the more than 17,000 who work for American Airlines, said it even happened to flight attendants. "The passenger oftentimes can be accommodated on the next flight," Mr. Pharr said. But the flight can't go without the flight attendant. He added, "You usually only do that once." Richard S. DeFrank, an associate professor at the C. T. Bauer College of Business at the University of Houston who writes about travel stress, said travelers must "remember the kids and the dog and the suitcases, and quite often that could result in making the mistake." Dr. DeFrank continued, "It is easy for the stress to impact their cognitive functioning and to forget things like which airport you're going to." Joseph Desir, 63, who has been a cabdriver for 26 years, has faced the wild succession of emotions that accompany a passenger's realization so many times he said he was inured to it. "Ten years ago it was stressful, but now in my experience, there's nothing I can do," he said. Airports in New York City proliferated thanks to Fiorello H. La Guardia, the mayor from 1934 to 1945, said Joshua Stoff, the chief curator at the Cradle of Aviation Museum in Garden City, N.Y. The Jamaica Bay location of the original municipal airport, Floyd Bennett Field, was challenging to get to, so planes were often routed through Newark. In 1934, Mayor La Guardia refused to deplane in Newark, and insisted - successfully - that he be flown to Floyd Bennett. The new airports were built soon after. "He's the original one going to the wrong airport," Mr. Stoff said. La Guardia and Kennedy are only about 12 miles apart, but in rush-hour traffic, the trip by cab or shuttle bus can take an hour or more. Taking public transportation between the two airports requires at least an hour and a half, hopscotching from bus, subway or train. Getting to or from Newark, which is 35 miles from Kennedy across the island of Manhattan, is even more difficult. Some attribute the blunder to the pace of the city. When she thought her father was taking her from Englewood, N.J., to the Newark airport this month, Rachel Bhatia, 33, took a break from fiddling with her cellphone to find she was about to be driven across the George Washington Bridge to La Guardia. They made a U-turn. "We're all just running on all cylinders all the time," she said. I think it's very easy to look up and be about to take the wrong exit. (It may be familial. Last month her mother landed at one South Florida airport while her friends arrived to meet her at another.) These scenes occur around the world. When David Grossman of Brooklyn was traveling from London to Spain as an exchange student several years ago, he arrived at Heathrow Airport and looked for his gate. And kept looking. The actual flight, which he missed, was at London Luton Airport, which is one of six commercial airports that serve the London area. "Typical American arrogance," said Mr. Grossman, now 25, "thinking that the biggest airport would be the one for us." Ms. Leth, who prints out itineraries, is so ashamed when she messes up that she makes excuses to her drivers. But "the cabbies flat out know," she said. They just laugh at you when you get in.