"We'll be evaluating to see how we can tweak it," Morris said. "But it's here to stay (in Salt Lake City) for a while, if not indefinitely."

The pick-a-line process begins at the ticket counter with signs that read, "What is your line?" From there, passengers can follow the color and shape that correspond with their level of travel experience throughout the check-in process — black diamond, blue square (frequent travelers) or green circle (families or those needing special assistance).

"The theory is you'll have a calmer business traveler and calmer family travelers," Hawley said. "It just makes the process go more smoothly."

And calm travelers make it easier for TSA officials to pay attention to their top priority — identifying those who pose a potential threat to the safety of an airport or the aviation system, he said. "If the whole crowd coming at us is frustrated and upset, it's easier for someone who wants to do harm to mix into that," Hawley said.

Jeff Simpler of Austin, Texas, said he thinks the separate lines conceptually are a good idea.

"As a business traveler, I'd like to get the families and kids away from me," Simpler said.

On Friday, however, Simpler was in the family line, following the green circles with his wife, Melissa, and their two children. The family was returning to Austin after vacationing in Utah.