Are new TSA scanners slowing down the screening process for travelers?

In case you missed it, the U.S. Transportation Security Administration has replaced old screening lanes with new computed tomography X-ray systems at more than 200 security checkpoints across the U.S.

Currently, this technology is at all major airports, but not yet in every lane. If you've used these systems, as I have at LaGuardia Airport (LGA), you've likely noticed they do not require you to remove 3-1-1 liquids or laptops from your bags, among other changes.

Here's all you need to know about these new scanners, including how they differ from older technology and their efficiency in real-time.

CT X-ray scanning equipment is the latest TSA technology implemented at airport checkpoints nationwide. It's designed to "significantly improve scanning and threat-detection capabilities for carry-on bags," per a TSA spokesperson.

Passengers in these lanes do not have to remove their TSA-approved 3-1-1 liquids (3.4 ounces or smaller inside a clear quart-sized bag) or laptops, similar to how it works in TSA PreCheck lanes. Another difference with these scanners is that passengers must place every carry-on item, including luggage, into a bin for screening.

As of June, the TSA has deployed 678 CT units in 218 airports nationwide, with plans to add 1,200 more at airports this summer.

In addition to streamlining the steps for passengers by removing the often laborious process of travelers sifting through their stuff to find their electronics and liquids, CT technology uses 3D images instead of 2D. This further enhances the TSA's ability to identify explosives and other threats via a 360-degree analysis, per the TSA.

"These units provide a significant screening advantage, and they do create checkpoint efficiencies, particularly in standard screening lanes where passengers do not need to remove laptops and liquids," the TSA spokesperson said.

Overall, the TSA believes this technology is the best option available because the machines create a clear picture of a carry-on bag's contents that computers use to automatically detect explosives, including liquids.

"While passengers who are screened in security lanes with CT units do not need to remove their 3-1-1 liquids or laptops, there are a few things that can be done to hasten their progress through checkpoints with CT scanners," the TSA spokesperson acknowledged.

For example, some travelers who have used these machines, including TPG staffers and readers, have actually found them to slow down the security screening process overall. This is specifically because of the aforementioned requirement that everything must go into a bin, including suitcases. Even though this process may only add a few extra seconds for every person, no one wants to spend more time at a security checkpoint than necessary.

"The opening to the X-ray tunnel on a CT unit is slightly smaller than on a traditional X-ray unit, so we advise that travelers not force larger items into the tunnel," the TSA spokesperson said. "Bringing more slows down security screening."

Last month, Gene Sloan, TPG's principal cruise writer, used these machines for the first time at Asheville Regional Airport (AVL), where they were recently implemented.

"Asheville has very little business and business travelers, so there are few people using the TSA PreCheck line. Usually, it's a line just for me. But this time, I was 10-15 people deep in the TSA PreCheck line. And the regular line next to me seemed longer, too," he recalled of his May 7 experience.

"AVL is small, and we only have one entrance with two scanning lines, and we got two of these machines to replace the two old-style detectors. It just seems like the bags move more slowly through these bins," he said.

Nick Ewen, TPG's director of content, shared similar woes after going through the CT scanners at LGA.

"I've found that the time wasted is more significant once you've gone through the metal detector. Once the bins with your bags actually get in the automated system, it takes forever for them to come out," Nick said of his May 11 experience at LGA. "With normal X-ray screeners, once the bag is deemed approved, it gets pushed out, and you can go on your merry way."

"With these machines, you'll see your bag come out of the tunnel, and then it sits and sits and sits. The last time I went through LGA, more than 20 people were standing past the metal detector, waiting for their bags to come through," he said. "I timed it, and it was five minutes, two seconds from the moment I walked through the metal detector until I finally had my bag."

Many TPG readers shared similar sentiments after using the new machines in the TPG Lounge on Facebook.

Most travelers agreed their experiences in lines with the CT machines were noticeably longer. Since every item must be placed in a bin, the process became very slow. Also, everyone queued up at the end, waiting for their bags, which increased wait times. There were also a few complaints of confusion slowing down the process and a lack of communication from TSA agents.

As the TSA continues to roll out CT scanners with an automated system to push through security bins, you may experience a delay in how quickly your stuff moves through. Both the TSA and travelers alike have to adjust to this new process.

"It is equally important that passengers pay attention to TSA officer instructions at the conveyor belt," a TSA spokesperson said. "These officers may provide helpful advice for getting items through the CT scanners most efficiently."

Over time, the TSA expects this technology — like its new facial-recognition software — to eventually speed up the security process as people become more familiar with how it works.

"New technology has a definite 'burn in' period for passengers and TSA officers to become adept at using it," a TSA spokesperson said. "Familiarization over time will further enhance the efficiency of the units."

Outside airport security experts agree that this technology should eventually enhance overall efficiency for passengers.

"They do slow down the screening process for carry-on bags," Sheldon Howard Jacobson said. He is a computer science professor at the University of Illinois Urbana-Champaign who has written extensively about CT scanners. "The TSA hopes that the transportation security officers will get better operating the scanners and the algorithms will get better to reduce false alarms and keep passengers moving."

In theory, the fact that passengers don't have to take items out of their carry-on baggage should lead to a more efficient security process overall. It should result in reduced wait times at security checkpoints, Jacobson said. However, thus far, these systems have created a bottleneck of passengers all waiting for their bags at the same time because they can pass through physical screening faster than their carry-on bag can. This creates further confusion among passengers and TSA officers.

"Most people would think that leaving more items in a carry-on bag would mean that passengers spend less time at the security checkpoint," Jacobson said. "However, if the CT scanner is slower, then the time saved is lost by the officer reading and interpreting the CT scanner screen. Time is not saved; it is moved elsewhere."

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