There isn't really any planning. San Francisco never removes stop signs, but just adds them steadily as neighborhoods request them. Eventually they are turned

There isn't really any planning. San Francisco never removes stop signs, but just adds them steadily as neighborhoods request them. Eventually they are turned into traffic lights. (I imagine "traffic signals installed" must be a performance metric for someone.) A downside of having stop signs at almost every corner is that drivers seem to forget how to drive in areas without them. They assume that if they approach an intersection without a stop sign then they can drive through it at full speed, instead of looking for cross traffic and pedestrians.