PreCheck gets bigger in Chicago: Delta and US Airways get into O'Hare's TSA screening program

Two more airlines today joined an expedited security pre-screening program available to some travelers at O'Hare International Airport.

The Transportation Security Administration announced that Delta Air Lines and US Airways are participating in TSA PreCheck at O'Hare.

Under the program, which is open to frequent fliers and participants in the U.S Customs and Border Protection Trusted Traveler program, passengers traveling domestically are allowed to keep their shoes, belts and jackets on and leave laptop computers and liquids inside carry-on bags. To join the program, passengers must provide some personal information and undergo background checks.

At O'Hare, United Airlines and American Airlines previously started participating in the security program, which aims to focus increased security screening on travelers who are considered higher risks because the TSA knows less about them.

TSA PreCheck is now available in 20 U.S. airports.

"The continued expansion of TSA PreCheck at O'Hare benefits both passengers and TSA," O'Hare Federal Security Director Kathleen Petrowsky said in a statement. "The vast majority of air travelers present little risk to aviation security. By expediting screening for those we know more about, we can more effectively focus our resources on those we know less about."

PreCheck passengers receive boarding passes embedded with bar codes that airport agents read at the security checkpoint. Passengers may then be directed to an expedited screening line.

Airlines at Midway Airport are not yet participating in PreCheck, officials said.