Agent-Based Models or Modelling, abbreviated ABM , involves developing simulations of urban structure and dynamics at the level of how individual objects which comprise such systems behave. The best example and the one that is developed in my lecture today is models of how pedestrians move in space and time, in crowded situations. In fact we can define agents in cities as any irreducible set of objects – they need not be human and very often they can be aggregate populations in groups, buildings, streets and so on. As long as they have a dynamic and interact with each other and with other objects they are candidates for this ABM. An introduction is contained in my book Cities and Complexity: Understanding Cities with Cellular Automata, Agent-Based Models, and Fractals hanging around the office.