The program works this way: Participating travelers will walk through a dedicated lane at airport security checkpoints. They will provide the TSA officer with a specially marked boarding pass. A machine will read the barcode, and travelers deemed “low-risk,” will likely be allowed to keep on belts, shoes and jackets and leave laptops and liquids in bags when being screened.

Not everyone is eligible to participate in the program, which is already being tested at airports in Atlanta, Dallas, Detroit, Miami, Las Vegas, Los Angeles and Minneapolis-St. Paul. Eligible travelers are some of those who participate in American and Delta airlines’ frequent flier programs, as well as travelers in three other trusted traveler programs, which do charge fees to participate. About 336,000 passengers have been screened through the program since the testing began last year, according to the Transportation Security Administration.

By the end of 2012, the government expects select passengers in frequent flier programs for US Airways, United and Alaska Airlines to be eligible to participate.