It's about lines, it's about standing and shuffling, it's about time.
At Terminal 1 at Los Angeles International Airport, the queue for ticketed passengers with only carry-on baggage stretches out the front door, over a highway bridge, down to Terminal 2 - perhaps 250 yards away.
The line U-turns back over the same highway bridge, where it is funneled between two others (for tickets to the left, skycaps to the right).
"This is what it's come to, for the moment at least," says Anastasia Albanese-O'Neill, district marketing manager for Southwest Airlines, who is handing out inflatable airplane hats to keep kids happy.
This scene, a snapshot from the peak-congestion Thanksgiving weekend, serves as both a warning and a solace.
US Airports, including LAX, are having trouble coping with new demands to tighten security. But in this struggle, they are putting security before passenger convenience - and American travelers seem largely willing to abide the long lines and extra time this entails.
Highlighting the tension between stepped-up security and longer waits, Transportation Secretary Norman Mineta said this week he hoped the nation's airports would soon have a "no weapons, no waiting" screening process that limits passenger waits to 10 minutes or less.
LAX, an airport that is by some measures among America's most secure as well as most active, offers a window into the challenges facing US airports in the wake of the terrorist attacks of Sept. 11.
"We have become a crucible of pressure and change, trying to respond to the spotlight of terror," says Nancy Castle, lead spokeswoman for Los Angeles World Airports (LAWA), the city-run agency that oversees LAX. "The price of that pressure and change is a mandate for new security procedures that is literally growing day by day."
The largest aerial gateway to America via the West Coast, LAX is the world's third-largest airport in number of passengers. It also ranks first in people starting or ending their trips. That means that, unlike major hubs like Chicago, where many pass-through travelers have been screened at other airports, 80 percent of passengers here must be screened before boarding.
In recent months and years, that has meant millions more spent on screening technology from metal detectors to x-ray machines to devices that electronically "sniff" luggage to detect explosives.
Already equipped with 200 video cameras at locations from parking lot to gate, LAWA recently approved 900 more, some with a glass head as small as a fingertip.
Three other features of post-9/11 LAX: No use of storage lockers, harsher crackdowns on abandoned luggage, and the watchful eyes of National Guard troops common to all airports these days.
Officials have decided to forgo, for now, face-recognition cameras and software that can help identify travel passengers and match them against a data bank of known terrorists. Also possible in the future: hand- or iris-scanning devices that could confirm the identities of travelers or airport workers.
Currently, security efforts here revolve around traditional screening machines.
Pat-down body searches have become commonplace, to the consternation of some travelers.
"Do you mind if we pat you down?" a security worker asks one man.
"Yes, I do mind," he replies, but is frisked nonetheless.
No definitive data comparing airport security is publicly available, but among the nation's 25 largest airports, LAX has had the fewest security lapses on a per-traveler basis. And no one has been murdered here in the past 12 years.
But whatever its successes, all airports now face a higher security standard - and meeting it will be a joint effort among federal agencies, local authorities like LAWA, and the airlines - which for now are responsible for hiring the private companies that do passenger screening.
Thus, while LAWA oversees airport operations, it has no power to dictate security measures to individual airlines.
"We are adopting a whole host of new procedures and equipment, but we feel that to openly advertise what they are, while assuring passengers, can also [tip] our hand to terrorists," says Chris Nardella of United Airlines.
But there are many things that passengers here do see, feel, and experience.
First: no curbside drop-off or pick-up of passengers by private vehicles.
Facing a federal demand to screen incoming cars - out of concern for bombs in the middle of a horseshoe-shape terminal complex - LAWA decided the only way to prevent miles of traffic congestion was to check cars as they entered parking lots in the airport.
So passengers must hoof it from the parking structures across access roads to reach the terminals.
"It was a hassle, but I would rather do it this way and feel more safe than have it the other way around," says Matilde Maupin, a mother of three who has just descended four flights of stairs with two baby carriages.
The once-jammed curbside drop-off area now offers easy access for free-flowing shuttle buses.
But if the curbside feels eerily empty, it is the lines that are the distinguishing feature of today's LAX.
While the passenger loads are down 15 to 20 percent from last year, the time taken to screen each person has often doubled, tripled, or more.
In addition to the waits, passengers are now asked to remove belts and eyeglasses - not just empty their pockets of keys and change - to avert setting off the detectors. And some are randomly selected to put their checked baggage through additional scanners as well.
The procedure foreshadows changes that will soon become widespread as a result of a new federal law mandating that all checked bags be scanned.
At the entry to Terminal 1 here, passengers get a peek at a new machine - the CTX 5500 - that is in use here as of Nov. 15. Besides its capability of identifying bombs, the CTX 5500 has software enabling it to compute whether or not luggage has isolated components that could be used to make a bomb.
But getting all bags scanned by such machines is a huge undertaking - one that Transportation Secretary Mineta said this week may take longer than the 60 days mandated in the new aviation-security law.