What unites all these widely varied ideas is the fact that when designing it, the design team stepped into the shoes of the person in a specific situation. This first example illustrates this very nicely. When there's a fire in a building and it needs to be evacuated, the hallways might be filled with smoke already. When crawling on the ground to avoid breathing in the smoke and fume poisoning, it's a potential life-saver to be able to read the evacuation plan from the floor.
These evacuation plans
This furniture hardware
This building
This elevator
This door
This maintenance guy's shirt
This skateboard rack
This exit sign