Psychological time—as distinct from physical time—divides the past from the future by means of the experienced present and serves as a frame of reference for objects, events, actions, and persons. There are cases when our understanding of objects and events gains in depth with every additional time dimension, until we are able to arrange all the data in a meaningful sequence ranging from the past through the present to the future across time. A description of city traffic when confined to (...) the present is one step towards analysing special problems and understanding congestion in certain areas. The historical development of the city offers additional insight into the evolution of bottlenecks, while current changes, made by the municipal authorities, can only be understood in connection with a long-term development plan. A lecturer on town planning will, therefore, offer his audience a more profound understanding of the subject by combining a description of the visible present with a causal explanation of the past and a teleological account of future projects. (shrink)