Resilience Assessment Framework for an Urban Road Network Subjected to Disruptions

Abstract

This research paper introduces a novel framework for assessing the resilience of urban transport networks. Traditional approaches to quantify resilience primarily focus on evaluating resilience based on the accessibility and vulnerability of network links. However, this study proposes a different approach by considering the dynamic role of links within the overall network, including their ability to accommodate additional traffic demand from other links. To accomplish this, a comprehensive scanning network approach is implemented using an iterative traffic assignment performed. The framework is applied to the urban transport network of Karachi, Pakistan. The model incorporates parameters for calibrations derived from volume delay functions, specifically alpha and beta, which are obtained from actual traffic travel times during free-flow and peak hours. The accuracy of the model is validated by comparing observed traffic counts at various locations with the simulated traffic volumes, resulting in an average error of 9% and a standard deviation of 7.4%. The study's findings reveal significant losses within the network and identify critical links that are particularly susceptible to disruptions. The analysis provides valuable insights into delays experienced by travellers and the additional distances travelled when specific links are closed. Furthermore, the framework enables the evaluation of the overall impacts of disruptions at the network level. The proposed methodology will allow traffic engineers and decision-makers to effectively plan rerouted through alternative links during disruptions.