Joel Spolsky wrote in his blog recently about visiting the new 7 World Trade Center building. The basis of the entry was about the elevator technology used in the building, I found this very interesting. Basically you choose your floor from the lobby and you will be directed to which elevator to wait for, thus grouping like floor requests together. Great idea. Joel, in his analytical way, found a bug with this system as such:

People who aren’t used to the new system come into the lobby and see an elevator with an open door. They jump into it, and then get stuck going to some random floor because they can’t key in their destination once they’re inside.

At first read, I thought, sure that could be an issue, then contemplated it for a moment. Joel is thinking about how elevators work now, where a door would be left open for convenience. This wouldn’t be the case in the new system as a floor needs to be chosen first. OK, small oversight on my part–there are already people in the elevator, and someone is running for it (no chance this person will wait another 2 minutes for the next elevator). The leap through the threshold before the door closes, of course causing it to open and forcing all on the elevator to wait until it closes. Now I see how this person has a very small chance to get to the floor they desire. So I guess the users learn to enter their floor first after their first building tour, kind of a hammer over the head approach.

I have a feeling a keypad will be installed on the inside of these elevators as enough people complain, or they will just have to remember and conform. It does sound like an efficient system for a large busy office building. Perhaps I will try to look this up, perhaps at Otis.

I found this at the Otis site, its a system called “Compass™ destination entry” I am curious to here their response to the hurried passenger who jumps into a car to find no floor selectors.