Tom's Tech Blog

This item ran on the Joel on Software homepage on Monday, April 30, 2007
I had a chance to visit 7 World Trade Center today, the newest office high rise to open in New York.

Instead of having up and down buttons outside the elevators, there's a numeric keypad, where you key in the floor number you're going to. Then an LED display tells you which elevator to wait for. Once you get in the elevator, you don't have to press any buttons (and there are none to press).

This is more efficient than the old system, in which two people who were going to the same floor might have taken separate elevators, adding an unnecessary trip. Presumably, during the early morning rush, it is able to clump people going to nearby floors into the same elevator, thus getting more people to their destinations faster by intelligently optimizing elevator schedules on-the-fly, instead of letting any arbitrary person force any arbitrary elevator to take them to any arbitrary floor.

Can you guess the usability bug?

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. (end)