TSA should install gravity-powered tray/bin returns at its checkpoints.
Gravity-powered tray/bin returns are used at most European airports. The devices are usually just a pair of sloped rails. When a passenger finishes their screening, he/she simply places the bins he/she used on these sloped rails. The empty bins then slide, via gravity, back to the unsecured side of the checkpoint. The empty bins are then utilized by the next passengers entering the checkpoint.
This change would save money and cause TSA to perform better since it would:
(1) Eliminate the numerous TSA employees whose sole job function is to cart trays from the "secured" side of the checkpoint back to the "unsecured" side of the checkpoint.
(2) Reduce the number of Full Time Equivalents (FTEs) needed to staff TSA checkpoints, as well as the number of FTEs needed to supervise the checkpoints.
(3) Eliminate frequent TSA employee injuries suffered while manually returning bins to the unsecured side of the checkpoint.
(4) Reduce workplace compensation claims.
(5) Reduce sick leave usage.
(6) Increase security by eliminating the carts used to roll the bins around the scanning machines. (As these carts are not scanned, they are a possible of way of smuggling items around the scanning machines.)
A gravity-powered sloped rail tray/bin return system is clearly visible in this security video on the Bologna airport's website:
Here is a tinyurl, in case the above line does not work: