Data Driven Approach to Support the Design of Road Safety Plans in Portuguese Municipalities

Portugal aims to reduce road crashes and fatalities through the implementation of the European Union’s Vision Zero strategy. However, for municipalities, choosing effective interventions at a reduced cost is a challenging task. The choice of the proper countermeasures obeys to a series of constraints imposed by local budgets, municipal governments, urban planning strategies, existing infrastructure, and others. To aid decision-makers in designing Municipal Road Safety Plans that maximize safety at reduced costs, a planning approach was built. The proposed approach presents structured sets of countermeasures, linking crash types and site characteristics with potential interventions. The work used real road crash data from three Portuguese municipalities and comprised three stages. First, a cluster analysis to identify and characterize road crashes according to crash type (e.g., vehicle type, number of vehicles) and crash site (e.g., road alignment, cross section, intersection type, visibility). Then, a literature review and an empirical study supported the identification of possible groups of countermeasures for each crash type, and the specification of sets of interventions for each countermeasure group. The final proposal was confirmed by selecting crash hot spots from the original database evaluate if the measures had been correctly assigned to each crash type, providing both exemplification and validation. This work highlights the potential for a structured approach to identify efficient and cost-effective solutions when planning road safety interventions to be included in Municipal Road Safety Plans.