Towards spatially explicit agent-based model for simulation of informal transport infrastructure indirect growth dynamic in informal settlements

The informal construction of dwellings (housing) and the informal growth of transport infrastructure are two main dynamics of an informal settlement growth phenomenon that may influence each other over time. Some studies have been done to understand the growth mechanisms of informal settlements, but not enough attention has been paid to study the informal growth of transport infrastructure dynamic. In this study, the morphology and spatial pattern of different types of informal settlements have been reviewed and categorized to clearly define and formulate the mechanisms of informal transport infrastructure formation in the context of informal settlement. To this end, two different dynamics have been suggested in this study for modelling of the growth of informal transport infrastructure. In the first suggested dynamic, the infrastructure is extended directly as the result of consolidation of the physical signs of dwellers' movement (foot prints) on the environment over time. In the second proposed dynamic that is the main focus of this study, the informal infrastructure growth could be considered as the function of dwelling construction (housing) dynamic in the settlement. In this context, informal transport infrastructure is extended based on an indirect dynamic by consideration of the void spaces by dwellers as the accessibility corridors in the settlement during the construction process of the settlement. Finally, to study the validity of the second proposed dynamic for modelling of the indirect growth of informal transport infrastructure, a simple conceptual model was developed and tested and the results were evaluated and discussed.