The security lanes also included one of the "whole body imaging" devices now employed by the Transportation Security Administration. The device allows workers to look through a subject's clothing in an effort to screen for weapons as an alternative to more time-consuming physical searches.

"It basically will pick up anything that is blocking the skin of the person," TSA supervisory officer Joe Bause said. "Anything that has a density will stop the ... waves. It is almost like a sonar."

TSA installed the screening device at a cost of about $180,000, said Dwayne Baird, public affairs manager for the TSA.

The system is divided into two major parts. One is a large, clear booth where a passenger stands for screening; the other is a small, windowless room about 50 feet away where a TSA worker views the image. A worker in the viewing room cannot see the passenger in the booth nor can anyone outside the room see the image, which is displayed on a computer screen.

The images are not saved and subjects are not identifiable.

The device is used only when a passenger is pulled randomly from the regular security line for a more thorough search.

At that point, the selected passenger can choose to go through the imaging device or opt for a traditional "pat-down" search.

It takes about 30 to 45 seconds to go through the screening device and no touching is involved.

A pat-down search can take several minutes or more because the subject has to be taken to a shielded area and wait for a TSA officer of the same gender to conduct the search, which involves touching.

"It takes a lot less time than a pat-down," Baird said of the imaging device.

In addition to McCarran, the imaging devices are in use at airports in Baltimore, Los Angeles, Phoenix, Denver, Dallas, Detroit, Miami, Washington, D.C., and New York.

They are expected to be installed in Chicago; Atlanta, Newark, N.J.; Boston; Indianapolis; Tampa, Fla.; San Juan, Puerto Rico; and San Francisco.

The new security checkpoints also use advanced technology X-ray devices to screen baggage. The technology produces a high-definition image of a bag's contents for screeners, resulting in fewer manual bag searches.

The upgrades at McCarran come at a time when Las Vegas in general and the airline industry in particular is struggling to retain customers.

Still, airport managers say the combined $263 million in upgrades unveiled Tuesday are critical to helping McCarran handle long-term increases in passengers without becoming so crowded and chaotic it leaves customers with a bad impression of Las Vegas.

With the addition of 12 lanes Tuesday, there are now 44 security lanes at McCarran, compared to 12 in 2001, when the Sept. 11, 2001, terrorist attacks prompted major security overhauls that created chaos and delays for passengers.

The nadir for post-Sept. 11 travel inconveniences at McCarran was perhaps in 2004. That's when a surge of passengers leaving the International Consumer Electronics Show backed up at security checkpoints and caused wait times of more than three hours.

On Tuesday, Clark County Aviation Director Randall Walker said the new security checkpoints are the culmination of efforts that began in 2001 and resulted in many changes at McCarran.

"We knew we couldn't let lengthy checkpoint lines become the norm," Walker said.

The new security lanes are in an annex near the Southwest ticketing counters and lead to the C gate departures.

By adding the annex, McCarran managers decreased the walk from Southwest ticket counters to C gate departures by as much as 1,000 feet, depending on the gate.

They also will divert C gate traffic way from the combined C-D gate security lanes, which should make the process smoother for D gate departing passengers.

Later this year, airport management will open a pedestrian bridge from the C gates to the B gates. The bridge is on the secure side of the checkpoints and will eliminate the need for connecting passengers to take a shuttle bus between the concourses.

The bridge will be the last major capital improvement to McCarran until 2012 when a new terminal building opens at a cost of about $2.4 billion.

The other airport improvement opened on Tuesday was a new wing of the D concourse. The new wing includes nine arrival and departure gates.

Standard & Poor's analyst Kurt Forsgren, who has studied and rated the debt McCarran used for the upgrades, says the investment makes sense even though the Las Vegas economy is in a down cycle.

The debt is backed by future airport revenue from airline fees, concessions, slot machines, parking and other sources.

It's used for the upgrades unveiled Tuesday and the upcoming new terminal, all of which will help the airport reach a maximum capacity of about 53 million arrivals and departures, about 11 percent more than the 47.7 million it accommodated in 2007.

"They have to plan even though things at the moment don't look so great," Forsgren said. "The historical pattern is things do recover."

Contact reporter Benjamin Spillman at bspillman@reviewjournal.com or 702-477-3861.