When I was in Las Vegas recently, staying in the Luxor, I experienced one of the worst designed pieces of technology that I've seen in a long time. Every day when I returned to the hotel, I had to get the lift back to my floor.
Each of the lifts had the same restriction in effect - you need to insert your room card, and wait for it to register (which sometimes doesn't work first time). Once it has been accepted, a green light will illuminate (if not, you get a red light or yellow light.) I have no idea why there are 3 possible states! Then you have about 4 seconds to press your floor button. If you press it in time, the floor button illuminates and locks in. If you miss your window (or someone else presses an illegal button) then you have to start the whole thing again.
OK, well it's a bit of a faff, but what's the big deal, you may ask. Well it's true that if you are riding the elevator on your own, it's awkward but doable - but as soon as you have more than a couple of people in the room the whole system resorts to chaos. Let's imagine there are 3 people, wanting to go to floors 3, 7 and 11. (It gets even more crazy when the lift has 6 or 7 people and not everyone can reach the buttons!). Anyway, in this example, Mr. 7 happens to be first, puts his card in, and presses the button. The lift starts moving towards floor 7. So now we have a lift that's in motion, but most of the people in the car haven't put their floor in yet. Mr. 3 puts his card in, and after a couple of tries gets it to accept. But we've already passed floor 3. So the button push is rejected. He has to wait until the lift is descending. Which means it's Mr 11's turn. He puts his card in just as we're arriving at floor 7. But before he can push the button, the lift (which now thinks its free) gets summoned to the ground floor. 3 and 11 are now right back to square one, on the ground floor. And so it goes on! It can take several minutes and unnecessary journeys to actually reach your floor, not to mention all sorts of unfamiliar social situations for which there is no established lift etiquette!
This is a great example of how designers can easily fail to consider their users when adding new features. The reading of the room card was clearly added for security - but they completely failed to consider the dynamics of how it would work in practice in a crowded lift.
