Sometimes, what may seem like a bad idea turns out to have an excellent rationale behind it1).
Consider the image to the left.
Note the sign at the top of the image, announcing in print that the audible street-crossing signal is activated by holding the button for 3 seconds.
One might reasonably think this is rather silly. Audible crossing signals are for helping blind people negotiate intersections. Blind people can't read that sign. Therefore, the sign is useless. QED2).
But wait! Surely our culture is not (yet) so absurd that money and effort would be expended to make such a purportedly silly sign. Right?
We can assume that most blind people are already acquainted with the standards (e.g., beaconing) implemented to help neutralize their disability. So they'd already know about pushing the button for 3 seconds. But there are other personas in other situated use cases that could benefit from these signs.
Assuming that the signs are there for a good reason, can you think for what scenarios and personas these signs were intended?
Think this through before clicking below to find out the actual reasons.
Since I first introduced this case study, others have pointed out similar situations. One of them is shown to the right.
You can probably identify where this photo was taken, and go visit the site yourself.
Besides the signage, though, do you see any other problems with how this situation came to be? Can you think of what circumstances might have led to it? Can you think of how one might prevent such problems from happening in the future?