Abstract: An efficient freight transportation network underpins economic stability and regional logistics performance. Disruptions to critical infrastructure, such as bridge closures, challenge network reliability and expose vulnerabilities in freight flow management. This study examines freight network resilience through an analysis of the 2021 I-40 Bridge closure in Memphis, Tennessee, a critical disruption lasting from May 11 to July 31. To accurately isolate the closure’s impact from other influencing factors, this study applied the Augmented Synthetic Control Method (ASCM), a causal inference approach suitable for estimating the effects of infrastructure disruptions. ASCM constructed a counterfactual scenario using structurally similar, unaffected corridors to project truck volume and speed trends had the bridge remained open, thus enabling a robust estimation of the disruption’s direct and spillover impacts. Results indicated a substantial drop in truck volume on the disrupted I-40 Bridge corridor, with an average daily loss of approximately 8,700 trucks. The nearby I-55 Bridge captured a large portion of diverted traffic, while I-240 and SR385 also took in notable amounts. By contrast, other non-bridge segments, such as portions of I-55, did not observe similar gains, highlighting uneven responses across the network. Despite these volume shifts, traffic speeds remained relatively stable on alternative corridors, with only a minor reduction on the I-55 Bridge. This stability suggests the network holds sufficient spare capacity and flexibility to manage the rerouted freight flows. The findings underscore the importance of corridor redundancy and targeted capacity planning to maintain effective freight operations during critical infrastructure disruptions.

Mohammad Khojastehpour is a Ph.D. student in Transportation Engineering at the University of Tennessee, Knoxville. His research focuses on traffic operations, freight transportation, and transportation system resilience, with an emphasis on data-driven analysis of real-world problems. He has worked on projects involving traffic monitoring data, freight network performance, roadway incidents, and infrastructure disruptions.

His recent work includes studying freight network resilience during major bridge closures, analyzing the operational impacts of incidents on freeway systems, and contributing to shipper behavior studies. His interests include freight transportation, network resilience, and improving transportation system performance through practical analytical methods.