Bus Usability, Part III

[diversions]

Yes, I do intend to finish this series. Here is where it all began. [Edit, Feb 25 23:47 Okay, for backwards navigability, here is part two.] Today, I get to write about the hilarity that ensued from the incomprehensible instructions that were originally posted.

It was with a mixture of pity and silent frustration I watched poor passengers struggle with the new mechanism. Often people were just baffled by the closed door in front of them. A lot of people didn't even notice there was a sign with instructions. In usability, knowing your users is paramount. Here, the very people who need the instructions most are likely to be flustered and will not read anything with more than three words, and smaller than a 50 point font.

Not long after the introduction of these buses, I began seeing words scrawled on the doors. They said, "touch here," and had arrows pointing towards the general location of the beam of light. Maybe they were written by bus drivers, tired of explaining the system and tired of delays. I felt this to be a vindication of my own idea. There was no hand symbol, but they followed the principles that led me to my design: forget about the mechanism; use few words; elicit the right behaviour. It gave me a great deal of dark satisfaction to see those homemade signs.

Eventually, most of those light-beam mechanisms were replaced with a couple of completely different and more obvious systems, one of which is pictured here on the right. Again, I apologize for the poor focus. The French translates as "to open door, wait for green light, then push bar." Now, to be clear, the bar is still a trigger for a mechanical door; the passenger is not merely using the bar to push the door open himself.

This is a much better mechanism. It has more of what I call immediacy. A bright yellow bar right in front of the passenger, hand-sized and just screaming, "hold me!" Some people will trigger it accidentally because they happened to be holding the bar as the bus came to a stop. This is a good thing. Needless to say, an invisible beam of light has zero immediacy.

Another system that replaced the light-beam was a pressure sensor in a slightly recessed area of the floor, just inside the door. This is the same as the mechanism that was used in older, non-low-floor buses, so were very familiar, and rarely caused confusion.

Well, this was supposed to conclude my musings about bus usability, but the other day, I thought of the best possible door-opening mechanism ever. It's dead obvious, easy to use, and needs no instructions. It should be usable in any industrialized country in the world, and probably most developing countries. I'll unveil it in part four...