Think of the road-crossing; as described in the sign in the picture, there are three standard symbols for pedestrians. Unlike the three light colors in the traffic signs for vehicles, the crossing signs come with behaviors. A yellow light can mean “slow down” or “speed up” depending on the context, since the color is describing something that will happen – the light’s imminent change to red – rather than prescribing a single pattern of action. In the picture on the left, the first two symbols come with instructions for pedestrians: the walking figure means you ought “start crossing” while the blinking hand means you ought not “start crossing” but should continue if you have already entered the crosswalk. The third however, the solid hand, does not prescribe behavior, but proscribes a state of existence, “pedestrians should not be in crosswalk.” The incongruous language is necessary because the behavioral instructions of the solid hand are no different than those of the blinking hand. After all, pedestrians do not freeze in place when the lights of the hand stop blinking, nor would the State want them to. Rather, walkers cross more quickly, leaving the street so as not to continue to violate the injunction not to be in the crosswalk while the hand does not blink. Also to avoid getting hit by cars. That’s important too.
If it has nothing to add instructively, why the division between the blinking and non-blinking hands? If pedestrians followed the rules, only two symbols would be necessary: one for when it’s okay to start crossing and one for when it’s not. Of course, we know that pedestrians rarely if ever follow the stated instructions for street crossings. If we arrive at the corner just as the hand starts blinking, or if the street seems easy to cross in the time before the solid hand of banishment emerges, then we cross. Pedestrians and the State have a different idea of how long it will take to cross streets, and there aren’t enough cops in the world to make sure people stick to the stated rules. In the actually existing crosswalk, the third term is very useful. The blinking hand serves as the equivalent of a yellow light: pedestrians walk quickly or stop based on the context. The three-term logic is based on the premise that we will not follow the instructions as stated. These rules are literally made to be broken.
The crossing light is a tool for the State management of behavior, whether this involves adherence to the actual rules or not. In this case, people’s behavior can be better managed by creating a system of rules that will be broken, but broken in ways built into the rules themselves. I’m sure there are far better examples of this phenomenon, but this one has always seemed particularly overt to me. The State lists the rules on street corners for god’s sake.