AbstractAs one of the principal lifeline systems, transportation networks are crucial for evacuation during extreme weather events like hurricanes, and critical network links must remain intact. The conventional evaluation measures prioritize to achieve the maximum system efficiencies, and therefore they estimate the functional criticality of a road network using measures such as travel time increase or throughput reduction caused by a link disruption. This study asks a fundamental question on equity achievement of such measures and develops a new framework to incorporate road users’ vulnerabilities in identifying critical network links. This study introduces new evaluation measures that integrate the most vulnerable zones for evacuation prioritization based on social, environmental, and economic vulnerabilities. Results show that the critical links for the vulnerable population during an evacuation are not always identified by conventional link-based measures that emphasize overall system efficiencies. Among the links selected as critical using the throughput measure, only 25% serve socially vulnerable communities and 38% serve environmentally vulnerable populations. This highlights the importance of considering road users’ vulnerability when prioritizing resources to strengthen the links since a link disruption may cause more significant consequences for vulnerable road users. Decision-making to identify critical links and minimize the impact of disruptions remains critical to distribute resources more effectively during an emergency and support the timely and safe evacuation of vulnerable populations that should be prioritized to achieve more equitable evacuation and disaster responses. An online interactive map is developed based on the results of this study to show the exact location of the critical links and other important metrics.Practical ApplicationsIn general, network links that carry higher traffic volume and ensure connectivity to isolated subnetworks represent critical links because disruptions on the links would impact more people, with a greater magnitude of travel time increase from rerouting or rescheduling. However, the individuals and communities that use the infrastructure determine the importance of the road links during extreme weather events. If a certain link serves at-risk communities (e.g., lower income or older population) for hurricane evacuation, the link should be considered critical regardless of its total traffic volume or impact on travel time if disrupted. These links must be resilient to save lives within the neighborhood, facilitate the evacuation of vulnerable groups, and strengthen the region’s overall resiliency. The proposed research identifies the criticality of network links by identifying the community impacts of network disruption. In particular, this study focuses on developing a framework to determine the critical network links based on the vulnerability or importance of communities in a hurricane-prone area using three vulnerability measures and compares the results with the outputs of traditional measures.

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