ROAD NETWORK ANALYSIS FOR RISK AND RESILIENCE ASSESSMENT FRAMEWORK OF ROAD INFRASTRUCTURE SYSTEMS

Abstract

Maintenance and protection of road infrastructures (RI) against multi-hazard events requires the use of risk assessment to identify threats, to assess vulnerabilities and to evaluate the impact on infrastructure systems according to the probability of occurrence of such threats. Dealing with a complex network system, such as RI, demands the improvement of the risk assessment approach by resorting to the concept of resilient infrastructure, capable of dealing with scenarios linked to disastrous events with the aim of minimizing service interruptions and quickly recovering. In this paper, the network analysis of an RI case study is addressed to obtain a qualitative measure of resilience related to travel patterns of road network. The topology of RI system, a pattern of connections according to graph theory, between components interacting jointly to provide the required functionalities, is supplied by road network data from OpenStreetMap. Then a probabilistic system model is used to define a non-degradated condition and the scenarios of failure events that can affect the network system. For each condition, the evaluation of the related shortest paths, as a measure of the network system performance, provides the qualitative resilience measurement identifying performance criteria or levels of service requirements. The proposed assessment through transport network measures can find application in risk assessment and management by RI owners and managers.