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We also considered how best to indicate which floors the elevator would travel to. When an elevator needs to travel in both directions, it may make sense for users travelling to a floor in the second direction to wait until the elevator returns to get in. We wanted to include floors in the second direction in the interface so users would know they had gone to the correct elevator. However, we did not want to display them in exactly the same way as floors the elevator would travel to immediately. While the arrow should ideally indicate to users which floors the elevator will go to first, we found that users were confused by the initial arrows, so we wanted another way to represent the fact that the elevator would not travel immediately to those floors. We decided to highlight the floors in the button array but not display them in the scrollbar. This clearly indicates there is something different about those particular floors. Seasoned users will know immediately what it means, and the discrepancy will prompt new users to look further at the interface at which point they will hopefully discover the arrows and be able to figure it out.
The third part of our interface is inside the elevator. A list of floors the elevator will be stopping at is displayed, in order. An ETA is displayed for the most proximate floor. Below this display is an emergency exit button, which will stop the elevator on the closest floor possible, even if a stop on that floor was not planned. Pressing this button also causes an alarm to sound, to dissuade users from abusing the button. Not shown in our simulation are the standard, required elevator buttons, such as emergency call. While these buttons should still be present, they aren’t relevant to our design.
We considered including an ETA for each floor the elevator was traveling to, rather than just for the most proximate floor. We decided against this for two reasons. First, having a list of countdowns all changing by one second at the exact same time looked busy and rather ugly. And second, the ETA for the floors that are further away are necessarily less accurate than the ETA for the floors that are close.
The emergency exit button was a little controversial at first within our group. Anything that gives the users control of the elevator from within the elevator is going to be abused, and will decrease the efficiency and effectiveness of our new system. In the case of an emergency exit button, a malicious user could walk into the lobby, enter any elevator going past his desired floor, and use the emergency exit button as it approaches his target destination. Now this user does not have to wait, and everyone else in the lobby is inconvenienced as the elevator-calling algorithm is bypassed. However, we felt that an “quick-stop” button was very important to our system not only for safety reasons, but also to give users a feeling of control when they use our elevators, which lack traditional floor selection buttons. We believe that we’ve countered the potential abuse of the button to a degree by pairing it with an obnoxious alarm. Users are dissuaded from abusing the button by social pressure from everyone in earshot of the alarm.
IMPLEMENTATION
Three interfaces make up our elevator system, one for the lobby, one above the elevator, and one inside the elevator. For clarity, we have grouped our implementation details by the relevant interface.
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