Travelers flying out of  Rhode Island TF Green International Airport need not be so careful what they pack in their carryon bags.

On Monday the TSA announced it has completed the installation of an additional five CT (Computed Tomography) scanners.  The airport had already installed the first two scanners in January, allowing passengers to proceed through security checkpoints without needing to unpack their luggage or separate liquids and electronics. They still need to take off their shoes.

Senator Jack Reed was on hand for the grand unveiling, saying that “by making these investments, we are making this one of the leading airports in the country for safety.”

“I’m not just looking at this as a senator; I’m also a frequent flyer,” Reed noted, saying that the streamlined security process will also save travelers time and frustration.  The senator passed through the new checkpoint himself shortly after delivering his remarks, boarding a flight back to Washington.

Daniel Burche, Director of the Transportation Security Administration in Rhode Island, said that both the accuracy and the speed of security checks will be improved by the devices, which can process an average of 150-160 travelers per hour per lane.  By the time the final scanner is installed in June, the airport will be able to screen over 1,000 passengers per hour.

“The last unit we are installing will have slightly different capabilities, including the capacity to scan larger items,” he said.  Burche said that the devices have additional abilities which he was not at liberty to discuss, but that they included “next generation capabilities” for threat detection.

CT scanners have been used in a medical context since the 1970’s, allowing doctors to collect detailed, three-dimensional internal images of a patient’s body using a rotating X-ray tube paired with computerized image reconstruction.  The invention won Allan Cormack and Godfrey Hounsfield the 1979 Nobel Prize in Medicine, and roughly 80 million scans are ordered by American doctors each year.

The devices installed at TF Green operate using similar technology, representing a massive improvement over the two-dimensional X-ray images which the TSA’s current scanners generate.  Operators can rotate images, zoom in on them, and even “slice” material out of the picture in order to get a clearer image of what is underneath a layer of packed goods.  Screeners have 30 seconds to evaluate each bag before they are automatically flagged and moved down a separate conveyor belt for human inspection.

The scanners are also programmed with algorithms meant to analyze images for evidence of explosives or other suspicious shapes; this luggage is likewise automatically flagged for an agent to inspect.  According to Burche, the TSA has so far installed 287 of the 300 units planned for airports across the country, as part of a $781 million contract.

Although the new scanners are expected to cut down security lines in the long run, Burche warned that their may be delays TF Green’s roughly 150 Travel Security Officers familiarize themselves with the new devices and travelers adapt to new regulations.

“We expect it will take our staff a few days to acclimate,” he said.  “It might take even longer for passengers.  We’ve done a very good job of conditioning people in recent decades for what to expect when coming to the airport.  Now we’re suddenly telling them not to empty their bags, not to separate liquids, just to drop everything straight into the bin.  So people are going to be a little surprised by that.”

Long lines have been reported at a number of airports after the introduction of the new scanner, including at Boston Logan.  Some of these delays have raised concerns about the reliability of the algorithm, such as a recent logjam at Phoenix’s Sky Harbor Airport which occurred when the airport’s CT scanners (apparently fans of the Philadelphia Eagles) consistently identified Superbowl programs as explosive devices.

According to Burche, passengers can expedite the process by reviewing the new regulations prior to arrival, and pre-checking their luggage if possible.  He also encouraged travelers to reverse their typical packing procedure by placing light objects on the bottom of the bin and heavy items on top.

“Light things like clothing and jackets can easily get caught in the lead curtains at the end of the scanner,” he said.  “If that happens, we’re looking at a pretty long hold-up while we try to get things sorted out.  So placing heavier objects on top of the bin to weigh them down will help to avoid that.”