A coworker was telling me that the yellow line at CalTrain is a lot more important than we might think. If a person was to stand inside of the two yellow lines, the air pressure of a passing train might actually pull them into the train. This is an extremely dangerous situation, in-fact life threatening.
The painted lines provide some confusion, why are there two of them? Why are they both yellow? Which yellow line is being mentioned to stand behind? What exactly does behind mean? What if you don't read English?
This is a pretty simple concept and most people get it. However, when safety is involved it can never be clear enough. This is an interface in-between people and possible danger.
Let's consider the user for this situation. When designing computer interfaces, you assume the person is able to turn-on a computer, and they can execute your application or content.
For a train station you must assume very little. The person consuming this interface might not even be a passenger, they might be a vagrant. How would even a small form of ambiguity affect a person with thought disorders, schizophrenia for example? Could a small child wander close to this danger? Could the person be illiterate? Could this interface be so clear that even animals could consume it?
How could it be improved?
Wouldn't it be cooler if there was only one yellow line? Let's make the other line red, as you would assume it is even more dangerous to stand in proximity of that.
The platform affords that you stand on it. You stand while you wait for the train. Could we use a visual cue to show where?
Some simple improvements could make this a better interface.
