This is like the how it’s made of a website. I could read and click through an endless amount of these kinds of explainers.

My friend lives in a building with one of those super old elevators with the manual double doors and no queuing. It's the sort of elevator that someone probably got paid to operate once upon a time.

Using such a primitive elevator gave me a newfound appreciation for the complexity of modern designs. The queueing algorithms are subtle but clever, and the difference in efficiency is instantly obvious once you've dealt with the alternative.

Parking is a big factor too. Where you put the elevator when it is not being used can mean the difference between the doors opening instantly and worst case scenario.

In a similar vein, there was an interesting discussion [0] a while back about elevator buttons [1] and how timing for door close/open works, along with a bit of the history and regulations that go into them.

0: https://news.ycombinator.com/item?id=35152341

1: https://computer.rip/2023-03-13-the-door-close-button.html

I don't think it was mentioned, but the algorithm would be different based on the behavior of the majority. In some buildings most traffic is either up from lobby or down to lobby, e.g. it's very rare for people to go from floor 5 to floor 6. In some it's the other way around, where majority of moves don't involve lobby.

I wonder how a TWIN system with 2 cars per shaft factors in here: https://www.tkelevator.com/us-en/products/elevators/all-elev...

That will need planning and assignment I guess? But at what load figures does it become more efficient?

The elevator rabbit hole:

Deviant Ollam on Elevator Hacking https://youtu.be/ZUvGfuLlZus

Our elevator (4 cars) displays above each car the planned stops and can change mid-wait the car<>floor allocation and issue sound indication. I’d expect it to be allow optimal allocation.

Most importantly, after entering the elevator. First press the close button and then the floor. That way u, safe the time of pressing a button as the door is already closing.

Ahhh brings back memories of "Elevators from Hell" [1]

Now maybe I can beat that game!

1. https://www.dosgames.com/game/elevators-from-hell/