CHICAGO — After one canceled flight and hours of waiting at O'Hare International Airport, traveling software consultant Andy Simmons stood inches from a gate agent, who studiously ignored him and the other passengers in line.

Finally, Simmons recalled, the gate agent declared simply: "I'm out of here."

"You're out of here?" Simmons asked incredulously. It was 7 p.m. and the agent said she had been at work since 3 a.m., stopping only long enough to give him a withering glare.

And then?

"She just walks away. Now there's an empty podium and 10 people in line behind me, and nobody knows what to do."

In a summer plagued with delays, things are getting nasty.

This year, airline passengers and employees already frustrated by delays say they have added peevishness, anger, even shouting matches to their travels. Chances are not only greater that you will arrive late at your destination these next few months, they say. It's just as likely you'll have a thoroughly unpleasant time on the way.

"There's a lot of frustration and a lot of disappointment," Simmons said. "I think there's a lot of anger, too, because it doesn't have to be this way, right?"

In the University of Michigan's 2007 American Customer Satisfaction Index, which bases its ratings on thousands of passenger interviews, airlines scored lower than at any time since 2001.

The U.S. Department of Transportation noted that May's complaint rate was up 49 percent from the year before. In the weeks since, foul weather and computer outages have further played havoc with an air travel system operating at capacity and unable to respond even to routine problems.

AIRLINES RESPOND

There are some signs that airlines are concerned about passengers' wearing patience. United Airlines in January created the position of vice president for customer experience and hired Barbara Higgins, an executive from customer-friendly Disney Corp., to fill it.

Even a small carrier such as Midwest Airlines has given employees extra training in handling irate customers, while often using uniformed pilots to break news about delays and cancellations to take heat off overworked gate agents.

The question is whether the efforts are too little, too late, as irascible customers make their way through security and into a system rife with delays, flight cancellations and little help to overcome them.

"It's collapsing," said airline consultant Michael Boyd, of The Boyd Group in Colorado. "The system can't handle the weather. It's understaffed. It can't handle breakdowns."

Increasingly, neither can passengers.

"The stress levels at airports these days are off the charts," said Kelly Fryer, a frequent flier and executive director of the Chicago-based consulting firm A Renewal Enterprise. "From the moment people get into the gate area, they're already angry, frustrated and in some ways feel violated by the whole process."

Delays have lost their shock value, but this summer's impoliteness is stunning, said Phyllis Nutkis, who spent 48 hours trying to get to Chicago from Newark, N.J., starting June 27.

The low point came the next day, at New York's LaGuardia Airport, as a long line of irritable travelers snaked to a ticket counter. At the head of the line, a woman carried a cake in a box, Nutkis said. She was pleading to be let onto the next flight. She had a wedding to get to. She was bringing the cake, she told the gate agent.

"'Ma'am, you are where you are, and if you're still here later, I'd love a slice of that cake,'" Nutkis overheard him tell the woman. The woman put her back to the counter, slid to the floor and began weeping.

"Everyone around us was yelling, and we saw a few employees close to tears because people were just so rude. It wasn't their fault that the planes weren't taking off, but people were blaming them for it," Nutkis said. "People get upset because they don't know what's going on and they have no control and no power. And you just don't get any answers."

'CHANGE YOUR TONE'

Things don't look any better from the other side of the counter, said Gladys Montemayor, a Chicago-based flight attendant with United until last October.

"I would let them yell at me once, but a second time? I just wouldn't go for that. I'd say, 'You need to change your tone,' and I wouldn't hesitate to tell a pilot that someone needs to be off the plane," Montemayor said.

"When passengers finally do get onboard," she said, "you get the idea that they had just had it, that they were ready for a fight."

United's Higgins acknowledged that there is work to be done but said improvements are under way. What she brings to the table is 18 years of treating customers as "honored guests," she said.

"At Disney, we focused on managing high volumes of guests while delivering exceptional service on a consistent basis every day," she said. "At United, we are managing even higher volumes of our guests, and we want to be more consistent in delivering exceptional service."

The company has added more check-in kiosks and a new software system that automatically rebooks customers whose travel has been canceled, started new training to instill "a passion" for customer service, along with an outreach program that contacts passengers — before they contact the airlines — whenever there has been a significant travel disruption, she said.

'NOT A GOOD JOB'

But airlines also have been cutting staff, a recipe for frustration among those who are left, one expert said.

"We had a race to the bottom to see who could operate an airline with the fewest people. Now, when cancellation delays happen, there are fewer people to help," said Terry Trippler of TripplerTravel.com. "Working for an airline is just not a good job anymore."

Fryer, the airline traveler, said it couldn't have been clearer than in the Northwest Airlines terminal at Detroit Metro Airport the night of June 8, when hundreds of passengers were stranded there by East Coast weather problems, canceled flights and an FAA computer glitch that had snarled flights earlier in the day.

On a flight to Newark, Fryer, her Chicago-based consulting colleagues and the rest of Northwest Flight 650 were desperate for information about how to fly on. "For much of the night, there was only one woman" to help them, Fryer said.

Although varying explanations for the cancellations were given, one thing was clear: Nothing was flying east from Detroit. Westbound passengers were lining up at the gate for another plane, and the two groups mingled in a surly mob in front of the gate agent.

"She was so frustrated by the situation she was in, she literally got on the sound system at the gate and was yelling at the people in line, 'If you're in this line to get information about the flight from Detroit to Newark, I am not here to answer your questions. I'm here to get these people on this other flight,'" Fryer recalled. "She yelled this multiple times."

"The chances of you having a seamless experience when relying on the airline system are almost nil. The chances of having a terrible experience are really, really high," said Joe Brancatelli, editor of the Internet column JoeSentMe.com.

"You want my best advice?" he asked. "Stay home."