Risk assessment for highway transportation systems

This dissertation presents a risk assessment methodology developed for lifeline systems to serve as a tool in the decision process for: (i) retrofitting of critical structures in the system as a means of pre-disaster mitigation, (ii) pre-disaster emergency response planning, and (iii) emergency response operations. The objective is to assist in such decisions for minimizing life and property loss due to damage from natural or man-made hazards.; The methodology is based on vulnerability and importance assessment of the components in the system. Hazard analysis, structural classification schemes, and fragility analysis are employed to evaluate the vulnerability of each component. The importance of a component is assessed through network analysis and decision analysis methods. The network analysis methods are used to assess the impact of damaged components on the system functionality while various factors that influence risk reduction decisions are integrated using decision analysis methods.; While the concepts of the methodology are applicable to lifeline systems in general, the details are developed for highway systems subjected to earthquakes. The details of the methodology are discussed in applications to prioritization of bridges for seismic retrofitting, and emergency response planning and management activities.; As part of the vulnerability assessment for highway systems, new bridge classes and damage states are defined. An expert system is developed for classification of bridges (ESCOB). The importance criterion is assessed through a decision model using multiattribute utility theory. The impact of bridge functionality on the system performance is introduced as part of the importance assessment. Algorithms for connectivity analysis for emergency response (CAFER) and serviceability analysis are developed and are used to determine accessibility of the disaster areas, available routes to the disaster areas, travel time delays and socioeconomic impacts.; The methodology is implemented in a geographic information system (GIS). An interface is developed to use GIS concurrently with a land use transportation system (LUTS). The application of the methods are illustrated by several case studies for Palo Alto and Northridge, California areas.