Resilience-Based Prioritization of Bridge Retrofits in Seismically Active Regions: Lessons from South-Central Alaska

This study presents a resilience-based framework for prioritizing bridge retrofits by integrating structural vulnerability, seismic exposure, and network functionality. The approach combines bridge condition data, scenario-based seismic modeling, and geographic information system (GIS) analysis to quantify risk and assess mobility consequences. Applied to South-Central Alaska, the framework identifies corridors where bridge damage would produce the most severe system-wide disruption. A weighted priority index (P) merges structural risk, redundancy, mobility importance, and retrofit feasibility. The model is calibrated and validated using observed bridge performance from the 2018 Anchorage earthquake. Results highlight several high-risk bridges along the Glenn and Seward Highways, where limited detour capacity amplifies network fragility. The framework provides transportation agencies with a transparent, data-driven tool for targeting seismic retrofits and improving regional resilience in Alaska and other hazard-prone areas.