RALEIGH — I have a bionic arm.

OK. That’s a bit of an exaggeration. I don’t have super-strength, I don’t work for the OSI, and I am, at best, a six-thousand-dollar man. But I do have a long, thin metal plate in my right forearm. As I have written before, the plate used to pose no problems at all, except for the occasional sharp pain after lifting a heavy object. But now, with the metal detectors in some airports attuned to pick up the tiny trace metal elements, I get some extra, unwanted “attention” whenever I fly.

If you’ve been through the post-9/11 airport security and wondered whether it makes any real difference, you’re not alone. I’ve noticed that once I explain the existence of my metal plate to airport attendants, they almost never check to see if I’m telling the truth. I could have been hiding a stiletto in my sleeve, for all they know (there was an exception to this rule, as I recall, at the Denver airport where a dutiful young lady asked me to roll up my sleeve).

A few weeks ago, my good friend Robert Poole and his colleagues at the Reason Foundation in California released an innovative new plan for airport security that would more reasonably match risks with security measures.

The core of the plan consists of dividing airline passengers into three categories: low-risk registered travelers, medium-risk travelers (most passengers), and high-risk travelers. The low-risk travelers would be part of a completely voluntary “Registered Traveler” program in which passengers could willingly choose to undergo in-depth background investigations in exchange for shorter security checkpoint lines. Registered Travelers who voluntarily and successfully complete the investigation process would be issued biometric security cards to confirm their identities before proceeding to the security checkpoint.

Medium- and high-risk passengers would be determined through the use of sophisticated and classified algorithms, updated to include the latest criminal and terrorist watch lists.

“Sorting passengers into groups will increase security by focusing greater resources on high-risk passengers about whom little is known, while simultaneously reducing the ‘hassle factor’ for all other travelers,” the Foundation observes. “According to a Delta Airlines survey, nearly 25 percent of their frequent flyers have cited the hassle factor as a reason for not flying since Sept. 11, 2001.”

The Reason plan would cost less than the current approach, shrink the size of government, and alleviate the concerns many have about their privacy under the current system. It’s a rational approach to a very real problem that impacts security, the economy, and personal liberty.

Unfortunately, rationality isn’t what many in Washington seem interested in right now.

Hood is president of the John Locke Foundation and publisher of Carolina Journal.