Safety, reliability, performance, resilience and sustainability of structures and infrastructure systems continue to provide emergent and key challenges to infrastructure risk management due to the frequent occurrence of natural and man-made disasters (such as earthquakes, hurricanes and tropical cyclones, tsunamis, terrorist attacks, and industrial accidents involving aviation and energy production), the infrastructure crisis and climate change. In addressing these problems, the analysis and management of uncertainties are unavoidable. The society can no longer afford to ignore congested roads, deficient bridges, aging dams, broken levees and water mains, among others. Furthermore, the importance of costs associated with managing existing structures, civil infrastructure and engineering systems in an era of finite resources is increasingly recognized. Decisions regarding requirements for design, continued service, rehabilitation or replacement, and management of risk should be based on optimization under uncertainty so as to balance conflicting requirements such as cost and performance.