+1 for the elevator anxiety. In my case there were no buttons inside the lift!! Really, nothing. One had to select your floor BEFORE entering the lift.
Also, surprisingly large no. of people make a mistake in selecting the floor they need to go to (visitors, new joinees...)
That wouldn't require changes to the user interface, and the doors would only open if someone can actually get on.
That, plus an assumption that most trips are between the ground/garage floors and one of the higher, occupied floors should be sufficient to reduce congestion without requiring someone to push a floor button before entering the cab. Adding a clock to the elevator controller would also help, such as by stationing empty cabs at the exit floors in the mornings, and distributing them among the occupied floors in the evenings.
I can think of a lot of ways to improve elevator scheduling without changing the user interface, and even if I did change that, I could certainly provide some mechanism to select a specific floor without installing a touchscreen GUI. Wave your employee access RFID badge at the button panel to pick the floor where your cubicle is, for instance.
There was a public restaurant on the top floor, so the lifts frequently contained panicky people riding up and down until they eventually got to the ground floor.
Also the lift systems occasionally crashed mid-journey. The lift would stop, the lights would go out and the LCD screen would blank and run through a boot sequence before everything came back up.
Stephen Fry once got stuck in one of them.
These were private office buildings though, I can definitely see the public restaurant causing havoc with its endless stream of noobs...
The building's now been turned into posh flats - there's no way I'd consider living there (apart from being almost infinitely out of my price range) without being sure they'd been replaced.
A traditional elevator only know where your are. This type of elevator also knows where you want to go and can optimise for passenger throughput.