In my experience, European setups limit the number of people that approach and use the system to one, maybe 2, at a time...the exact opposite of TSA yelling at people to cram together at them.

The bottleneck is the actual scanning and processing of the trays through the machine. TSA seems to think the more people they cram into the line to put their items out, the better. The opposite is true. You get stuck trying to push your tray onto the conveyer because everyone else is fighting for the same place in line.

Sorry to see them expanding use of these.