Philadelphia, Atlantic City, and other airports, including Seattle and Las Vegas, are a step ahead of the issue. They have some unmanned portals that replace paid officers.
Passengers exit through three sets of electronic doors in Philadelphia's Terminals D and E. The technology cost about $700,000, said Keith Brune, the airport's deputy director for operations and facilities.
Atlantic City International Airport has installed five cylinder-shaped glass exit portals since 2009, which save about $280,000 a year in staffing, airport spokesman Kevin Rehmann said.
Philadelphia airport plans to put electronic exit doors in Terminal F in the next couple of years.
Adding staffing in the other terminals, A West and A East, B, and C, to monitor exit lanes 18 to 20 hours a day will cost $1.7 million to $2 million per year, Brune said.
The airport industry argues that the TSA directive violates the Transportation Security Act that created the agency.
On Wednesday, the American Association of Airport Executives and Airports Council International-North America petitioned the U.S. Court of Appeals for the D.C. Circuit asking the TSA to delay implementation until the court ruled on the "merits" of the legal challenge.
Late Wednesday, the TSA rejected the request. The trade groups filed a motion Thursday, asking the court to grant a stay. A ruling is not expected for at least 10 days, a trade association spokeswoman said.
"TSA collects a security fee - every time you fly, there is a security fee attached to a ticket," Brune said. "One thing that fee goes to pay for is the security exit lanes. They are not giving up the fee."
The TSA said that about two-thirds of the 450 commercial airports nationwide currently staff exit lanes. Only one-third of airports do not.
Monitoring passengers exiting secure areas is not a screening function, but an issue of "access control," similar to perimeter fencing and gates for vehicles, the agency said.
Philadelphia airport was not responsible for the exit lanes even before the TSA took over the function a decade ago, Brune said. "Checkpoint security belonged to the airlines. It was an airline responsibility."
Brune said it was "very challenging" for airports to ramp up and "get this done in such a short amount of time." Philadelphia has been granted a 30-day reprieve, until Feb. 1, he said.
The TSA has said automated exit lanes are permissible, but issued no federal national standard on what's acceptable, Brune said.
Passengers breezing through the automated exit doors in Terminal E on Thursday liked the convenience.
"It's awesome. It's quick, and I don't have to deal with anybody," said Eric Juday, arriving from Indianapolis to visit his daughter, Brooklyn, a sophomore at the University of Pennsylvania.
"I like it because there's no backup. It's boom, boom. You're out."