We've heard for awhile about the new type of elevator where, in the lobby, you press the number of the floor you want, and then you go wait for the elevator that's going to that floor. No buttons inside the elevator, everything's an express trip. Well apparently 7 World Trade Center has them installed, and there are some usability bugs that may not have been considered. Joel points out one I hadn't thought of -- that people unfamiliar with the system will jump into the elevator and then be stuck going for a ride. I think that problem's got a built in shelf life, though, if the technology catches on. Eventually people will recognize the new elevator control as the way that it's done, and work with it.
I can think of some more human factors as well:
- You're having a conversation with your coworker who gets off on 7, but you work on 9. You can't ride up together for 7 floors, unless you want to get off on 7 and then wait for one going to 9.
- If you're going against traffic, like for instance you're on 7 and want to go up to 9 instead of down to the lobby, how long will you have to wait for an elevator? Won't the majority of trips be back and forth to the lobby? At least with the old system you could catch a ride on one that was heading up that would stop for you.
- How does the display in the lobby work? I've pressed 9, now somehow it has to signal to me to go wait at the C elevator. But in the morning rush hour say that there are half a dozen people behind me also heading for 9. Do they know that C is going to 9? Or do they each have to take a turn at the button?
- How many elevators are there, and how many floors in the building? Seems like there's a simple math problem there -- if you've got 10 elevators, and 12 people all come into the lobby heading for different floors, 2 people are going to be told "Sorry, wait for the next one," even though only one person is getting on each elevator.
- Are the door open and close buttons in these things, or are those obsolete now? After all, the door open button is really only for people diving for the elevator at the last moment (which I suppose could still happen, although as Joel points out not as much as it used to because most of those people weren't going to your floor anyway). Or it could also be for those times when you're staying on the elevator and holding the button for people to get off. But you're getting off too, so unless you're just being a gentleman and holding it for the others, it's unneeded. The door close button, meanwhile, is really only for those morons who need to get to their floor half a second sooner than they would have, so while you exit on your floor they sit their with their finger on the button impatiently waiting for you to exit so that they can hit the button and get their ever so faster. That problem as well is gone, since the only people on the elevator with you are people on your floor.
It seems like a technology that is good for rush hour times, but maybe not so much as the only solution. During the non-rush hour times when there's only a trickle of people using the elevators, it seems like there'll be mostly annoyances. In the article, Joel points out the example of "two people going to the same floor might have taken two different elevators, thus resulting in an unnecessary trip." True enough. But in this scenario if we have somebody going to 7 and somebody going to 9, then instead of having a single elevator make the trip to 9 and back down to the lobby, you have one go from lobby to 7 and back, and one go from lobby to 9 and back. That's far more wasteful.