Agents that keep track of the world
The simple reflex agent described before will work only if the correct decision can be made
on the basis of the current percept. If the car in front is a recent model, and has the centrally
mounted brake light now required in the United States, then it will be possible to tell if it is
braking from a single image. Unfortunately, older models have different configurations of tail lights, brake lights, and turn-signal lights, and it is not always possible to tell if the car is braking.
Thus, even for the simple braking rule, our driver will have to maintain some sort of internal
state in order to choose an action. Here, the internal state is not too extensive—it just needs the
previous frame from the camera to detect when two red lights at the edge of the vehicle go on or
off simultaneously