I've long held the idea that really really tall buildings need to have omni directional elevators. One shaft goes up, another shaft goes down. Each shaft has multiple cars following each other at different floors. When they get to the top or bottom, they switch across to the other shaft. Maybe even have shaft transfers at a few intermediate levels, and have a maintenance area with a few spare cars, maybe a whole unused shaft so they can switch around for maintenance. The advantage of this system would be the speed of filling or emptying a big building. The current system has one car in one shaft. Put 20 people in it then it takes 10 minutes to do a round trip before the next 20 people can get on. My way allows the same 20 people per car, but each shaft has say 10 or more cars depending on building height, so the same 10 minutes can move 200 people. Even if the trip is slower because the car in front slows your trip, you might be looking at 15 minutes round trip but that still equates to 800 people per hour, rather than 120. You just need a way to move cars between shafts. This looks like a way.