Today while traveling with a bus, I came across a bit unexpected behavior when I tried to stop the bus.

Expected Interaction

Briefly, while interacting with something it should at least produce information that a) it can be interacted with, b) it reacts on interaction and c) it confirms the result of an action was like intended. In my case this means that a) there are red stop buttons labeled “stop”, “push”, “press” etc. , b) these buttons reacts physically while pressed and c) I receive a sound and / or visual notification that my action had a reaction.

What I Experienced

This is what actually happened: there was a digital display, which would show a word “stop” when stop button is pressed. This display was empty at the moment, so I pressed one of the stop buttons which reacted normally. But nothing happened. No “stop” on display, no sound. Nothing. It’s quite obvious that either the button is broken or both the display and the sound speaker is broken. But since I remembered hearing a sound notification earlier on the trip, I was convinced that this very button was broken. Since my bus stand was already close I dived onto next button and pressed it. Same resolution: nothing happened. Well, tough luck.. until I suddenly noticed that the display has word “stop” on it. Hooray! Someone else had actually succeeded to perform the simple task I was unable to do. Then again, the “stop” disappeared from the screen. It took about four seconds and the word “stop” was there again. A blinking stop sign? A blinking stop sign with about four second intervals? And the sound notification only on first press (apparently someone else had pressed the button before me). I was just unlucky not to watch the display just while it was actually displaying the text. Practically that meant 15-20 seconds of uncertainty will the bus stop or not.

Why?

But the actual question I had in my mind was: what was the added value by having a very slowly blinking stop button? What was the person behind design actually trying to achieve?