The Transportation Security Administration is testing a plan that may mean the end to airline travelers needing to remove their shoes at security checkpoints.

A dozen companies have designed shoe scanning machines, and the TSA says it plans to buy 100 of the devices by next year, says an AP report.

 

The machines, which find metal weapons and explosives in shoes, didn't pass muster in tests three years ago. The developers of the latest generation of the machines promise better results, and the TSA says the technology will improve security, the report says.

 

The new machines range in size from a step stool to a turnstile. Some use electromagnetic fields to detect metal. Others use chemical sensors to detect explosives. The TSA said it wants a machine that finds metal weapons and explosives.