Bridge Proxy Indicators for Risk-Based Asset Management and Resilience Assessment

Extreme weather events pose serious threats to transportation infrastructure assets and cause difficulties for the transportation agencies managing infrastructure systems. Climate models predict an increase in the frequency and intensity of precipitation in many parts of the United States. Similar threats are expected as the developing climate trends continue to place increasing amounts of stress on transportation assets. Considering the uncertainties associated with climate trends and the ever-increasing stresses on transportation infrastructure, state departments of transportation need to assess their potential exposure to extreme weather, define appropriate vulnerability measures or proxy indicators, and plan to reverse the adverse effects of such hazards by developing mitigation strategies and planning response and recovery efforts for potential failures. Assessment of such exposure with high-fidelity models for all exposed assets is not possible. This requires a robust indicator providing an overview of the exposure, sensitivity, or adaptive capacity of a specific asset. This paper uses the available data for the state of Iowa to generate a suite of proxy indicators to assess the flood risk to bridges. The proxy indicators are stream channel instability, structural condition, and the criticality of the bridge to the network. It is expected that such proxy indicators, based on readily available data from existing national databases, could enable bridge owners to quickly assess potential vulnerabilities and start planning for them. The use of National Bridge Inventory data to develop and apply these proxy indicators will allow for scalability of the method to more US states.