Risk Management System for Road Networks Exposed to Natural Hazards

Road networks aim to provide mobility and accessibility to population, goods, and services. To promote and ensure this major goal road networks must cover most diverse geographies and territories being frequently affected by natural hazards. The effects of natural events directly affect the role of providing access in remote areas as well as ensuring an efficient mobility in major highways. Available risk management systems generally study the physical effects of natural hazards over road infrastructure centering efforts in the vulnerability of network components and the consequent economic losses due to certain levels of damage. Limited literature is available regarding the operational consequences over network mobility and accessibility and the socio-economic consequences to users and non-users. This article proposes an integrated management system that accounts for network risk in terms of travel time delays, the optimization of mitigation strategies to reduce risk, and the effects of considering other dimensions in decision-making such as social vulnerability and accessibility to critical infrastructure. The system considers the effects and consequences of seismic, flooding, and volcanic hazards. The models accounted by the management system consider hazard modeling and characterization, fragility of road infrastructure (pavement structures, tunnels, bridges, and cut slopes), social vulnerability of exposed population, network risk estimated in terms of travel time delays, and the optimization of mitigation strategies. The optimization process in addition considers a greedy randomized adaptive search procedure algorithm, funding allocation with budgetary restrictions, and network topological analysis. The proposed management system is applied to a road network exposed to seismic hazard in Central Chile. The system is intended to assist road authorities in the assessment of network risk and the development of effective mitigation strategies to increase road network resilience to natural hazards.