Human beings are not stationary creatures. We spend significant portions of our lives in transit, whether on foot, public transportation, or by car. When we travel from Point A to Point B, we invariably encounter other human beings. These encounters – and the way we navigate them – are governed by a very complex system of rules. Many of these rules are unconscious, many are a function of cultural norms, many operate under physical or artificial constraints, and many are decided instantaneously.