Identifying clusters and patterns of road crash involving pedestrians and cyclists. A case study on the Province of Brescia (IT)

Although road safety has improved in Italy over the last decade, the EU objective of halving the number of road deaths by 2020 has not been achieved yet. For pedestrians and cyclists, i.e., the most Vulnerable Road Users (VRUs), such trend is even worse: pedestrians’ road crashes have plateaued around 0%, and the one of cyclists has increased by 10%, compared to 2010. Therefore, VRUs road safety requires further commitment. Clustering techniques have been used in road safety analysis to investigate crash patterns. Latent Class Clustering (LCC) and K-Means clustering were mostly applied and specifically as a pre-processing stage for further statistical analysis. This study proposes a framework to detect crash clusters and related patterns and associate with them specific solutions from a predefined set of solutions, mainly based on infrastructural and environmental attributes. Specifically, starting from raw official statistical crash data, the framework adopts hierarchical clustering to structure pedestrians’ and cyclists’ road crashes in urban areas. The framework is applied to the Province of Brescia (Northern Italy) using crash data collected for the five-year period 2014-2018. Three clusters for pedestrians’ and five clusters for cyclists’ road crashes are identified and specific solutions to mitigate crash occurrences are suggested, accordingly. The provided insights and solutions may be useful as a decision-support tool for public administrators in improving road safety.