Integrating Network Connectivity and Structural Reliability for Transportation Network Reliability Analysis

It is necessary to assess how reliable a transport network is, so we can prepare for any unforeseen disruptions. There have been many efforts to measure road network reliability, vulnerability and system resilience. All these efforts have aimed to make the system more resistant to any negative effects caused by various hazards. A literature review has indicated a weakness in these methods to evaluate road network reliability. These methods only focus on one specific aspect of reliability such as connectivity, travel time, capacity or structural reliability. Although, to some extent, connectivity, travel time and capacity reliabilities are interrelated, they have been variably used for specific purposes. A methodology is proposed in this research which will examine a transport network for connectivity based on integration with structural reliability. The reason connectivity and structural reliability have been chosen is that both are significant for disruptions causing major damages. After occurrence of a natural hazard the main concern is to keep origins and destinations connected with each other for evacuations, relief works and transportation of material for reconstruction. The proposed reliability model is based on Max-Flow Min-Cut problem, which estimates the reduction in the link capacities based on their probability of structural failure. User Equilibrium flows are calculated through static assignment of a transport network. These flows along with link capacities are used to determine capacity utilization which is multiplied with estimated structural reliability of links. This provides a reliability value for each links which is further used to determine critical links in the network using minimum cuts. A standard hypothetical network has been analysed using the proposed methodology. Results of this analysis have been summarized along with proposed future research direction.