Optimal headway-based bus dispatching strategy under the influence of epidemic outbreaks

Document Type

Journal Article

Publication Date


Subject Area

mode - bus, place - urban, place - cbd, planning - personal safety/crime, planning - methods, operations - scheduling


Bus dispatching headway, Epidemic, Bi-level optimization, Wells-riley model, Social distancing, Vaccination


This study introduces a bi-level model to help identify the optimal headway-based dispatching strategy for bus transit network operations under the influence of epidemic outbreaks. Specifically, the optimal route-specific bus dispatching headways are sought to minimize the weighted total cost of travel time of all network travelers and medical treatments for newly infected travelers. Heuristic algorithms are developed to iteratively execute the proposed lower- and upper- level models in succession until convergence. Computational experiments are conducted for a 4-km urban bus transit corridor and a 7-square-km central business district (CBD) bus transit network, respectively. Without vaccination coverage, the total travel cost is expected to increase for higher infection rates. Implementing the optimal headway-based bus dispatching strategy could always reduce the total travel cost. However, mandating social distancing rules is largely more effective and a larger social distance becomes essential for higher infection rates. When the vaccination coverage reaches certain threshold levels such as 70% or higher, infection risks could be mitigated by the optimal headway-based bus dispatching strategy where no social distance becomes necessary. Model enhancements could be made to handle temporal and spatial variabilities of epidemic impacts and susceptible travelers.


Permission to publish the abstract has been given by Elsevier, copyright remains with them.


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