Evaluating disruption risks at the chokepoints of the maritime transport network to support re-routing decision-making

Maritime transport is crucial to global trade and economic stability, yet natural hazards and human-induced disruptions at key chokepoints pose significant risks to the reliability of the global maritime network. To address this challenge, we develop an agent-based model to examine how chokepoint disruptions affect vessel-level operations and re-routing decision-making and how these micro-level responses affect system-wide transport performance and trade flows. The model incorporates heterogeneous vessel characteristics, including estimation deviation and sensitivity to disruption, to represent adaptive routing under uncertainty. We evaluate the effects of disruption duration, estimation deviation, and vessel sensitivity on system performance, measured by recovery time, additional sailing distance, and delayed freight weight. Results show that even short-term disruptions can induce detours amounting to millions of additional kilometers, increasing operational costs and fuel consumption, and that the system may require one to two months to return to normal operations. We further analyze joint disruptions of the Suez and Panama Canals under various scenarios to demonstrate that disruption timing significantly affects recovery and disruption severity. These findings offer actionable guidance for vessel operators and logistics firms on when proactive re-routing is beneficial, and they inform port authorities and supply-chain stakeholders in designing contingency plans and improving risk management.