In what would be a major shift in procedures, the Transportation Security Administration is working on a concept that could let "trusted travelers" keep their shoes on, leave laptops in bags and avoid body scanners altogether—one of the biggest improvements at the airport since 2001.

Drawing data from airline frequent-flier programs, the TSA plans to identify trusted travelers and indicate their status with a bar code on their boarding passes, said the agency's administrator, John Pistole. When the boarding pass and valid...