Uncovering patterns in the distribution of traffic collisions at multiple spatial scales

Environmental and behavioural factors contributing to higher numbers of traffic collisions tend to be localised. As a result, traffic collisions also concentrate at specific locations. Multiple techniques exist to detect these hotspots, however, there are still open questions about the nature of the concentration patterns displayed by traffic collisions. By analysing data from different countries, we uncover some of these patters at different spatial scales. At the largest scale, we explore how traffic collisions are distributed across cities of various population sizes. To do this, we rely on the modelling framework of urban scaling, which we apply to traffic collisions of different degrees of severity. At a smaller scale, we study the distribution of collisions within different cities and observe similar behaviours regardless of the population size, demographic composition or location of the cities. Finally, we introduce an approach to quantify the level of concentration of traffic collisions in a given region. Whilst other approaches are not sensitive to the actual geographic distribution of the data, ours accounts for the spatial dependencies in the locations of the traffic collisions, so different spatial patterns in the data will produce different outcomes. Finally, we discuss the implications of our findings for policy as well as in the development of research into road safety.

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