Managing rockfall risk on the Italian road network with the new UX131 guideline

Rockfall is a severe natural hazard that poses significant risks to infrastructure, particularly along road networks. While commonly associated with mountainous regions such as the Alps and the Apennines, rockfall events also threaten coastal roads and tunnel entrances. To mitigate these risks, rockfall barriers are widely deployed. These systems are engineered to intercept falling rocks and dissipate their kinetic energy, with current technologies capable of withstanding impacts up to 10,000 kJ. However, the long-term effectiveness of these barriers is challenged by ageing and environmental degradation. To address this, the new guideline “UX131 – Metodologia per la gestione delle barriere paramassi a rete esistenti attraverso l’individuazione di classi di attenzione in funzione del rischio”, issued by UNICMI, introduces a structured methodology for the assessment and management of existing rockfall barriers. This initiative, whose concept was initially developed by the authors, is the result of a collaborative effort involving public authorities, engineers, geologists, and major barrier manufacturers, with scientific support from Politecnico di Torino. At the core of the UX131 guideline is a detailed inspection methodology that identifies and classifies potential damage types based on their impact on the barrier’s functionality. The inspection results serve as a key input to a multi-component analysis that integrates hazard, vulnerability, and exposure to determine the system’s attention level. This risk-based framework enables targeted maintenance strategies and enhances the resilience of Italy’s road infrastructure against rockfall hazards. An example of application will be presented, illustrating the practical implementation of the guideline and demonstrating its effectiveness in supporting decision-making for the maintenance and upgrading of rockfall protection systems.