A town planner, faced with the task of designing attractive walking spaces, needs a tool that will allow different designs to be compared in terms of their attractiveness as well as their effectiveness. PEDFLOW is an attempt to create such a tool. It is an agent-based, microscopic model of pedestrian flow where virtual pedestrians navigate a virtual environment. On their way towards a goal the agents, representing pedestrians, interact with features of the environment and with other agents. The microscopic, rule-based actions result in an emergent behaviour that mimics that of real pedestrians.

Pedestrians are subjected to a multitude of influences when walking. The majority of existing models only focus on a single aspect, typically the avoidance of obstructions or other pedestrians. PEDFLOW uses an implementation of context-mediated behaviour to enable the agents to deal with multiple cause-effect relations in a well-defined and flexible yet highly efficient manner. A variety of mobile and immobile entities can be modelled by objects in an object-oriented environment. The model is informed by an empirical study of pedestrian behaviour and the parameters of the agents are derived from measures of observed pedestrian movement.

PEDFLOW’s suitability for pedestrian modelling in the described context is evaluated in both qualitative and quantitative terms. Typical macroscopic movement patterns from the real world such as "platooning" and "walking with a partner" are selected and the corresponding emergent model behaviours investigated. Measures of service (MOS) are defined end extracted from the model for comparison with real world measures. As PEDFLOW was created as an interactive tool to be used in an office environment rather than in a high performance lab, the scalability and performance limitations are explored with regards to the size of the modelled area, the number of modelled pedestrians and the complexity of the interactions between them. It is shown that PEDFLOW can be a useful tool in the urban design process.