Micro-simulation Modelling of the Impact of Infrastructure Provision and Vehicle and Pedestrian Behaviour on Road Crash Risk

Microscopic computer models provide the opportunity to simulate vehicle and pedestrian behaviour under varying infrastructure conditions. Pre-crash and crash involvement risk at street, or even suburb level, can be explored and modified through various scenarios, such as: traffic calmed streets, pedestrian crossings, technology based infrastructure and other physical interventions. Models can simulate behavioural variation of both pedestrians and drivers by varying criteria such as: compliance levels (i.e. attitude to risk), headway distances, acceleration profiles, aggression, awareness and speed. These characteristics affect the outcomes of modelled existing and hypothetical scenarios and can be used to assess the potential crash risk at street level, for various states of behaviour of aggregated or disaggregated groups. Outcomes provide measures of road safety via proxies (or surrogate measures). The road safety risk for specific urban contexts should, therefore, be better predicted through an improved understanding of the interactions between infrastructure and vehicle and pedestrian behaviour. This paper outlines the road safety situation in South Africa and evaluates the use of microsimulation software as a tool to analyse the road safety risk of various local infrastructure scenarios through vehicle and pedestrian interaction.