Hate the full-body scans, pat-downs and slow going at TSA airport security screening checkpoints? For $100, you can now bypass the hassle.

The Transportation Security Administration is rolling out expedited screening at big airports called "Precheck." It has special lanes for background-checked travelers, who can keep their shoes, belt and jacket on, leave laptops and liquids in carry-on bags and walk through a metal detector rather than a full-body scan. The process, now at two airlines and nine airports, is much like how...