Multi-objective synchronization of public transport and shared modes: Model and application

Abstract

One of the main reasons for avoiding public transport is its limited network coverage, often leading to longer door-to-door travel times compared to private vehicles. To address this, better scheduling integration between public transport and shared mobility services is essential for reducing overall travel times and enhancing system’s attractiveness. To this end, this study addresses the Vehicle Routing Problem for shared mobility and the Public Transport Rescheduling Problem (VRP-PTR). The VRP-PTR is formulated as a combined problem, initially modeled as a mixed-integer nonlinear program (MINLP) and subsequently reformulated as a mixed-integer linear program (MILP), aiming to minimize both the operational costs for the service providers and the travel times for passengers. Given the multi-objective nature of the optimization problem, the $ϵ$-constraint method is employed to compute Pareto-optimal solutions. This approach is applied to a case study in Athens, Greece, where shuttle buses are considered as on-demand services that transport passengers from various pickup points to the most time-appropriate railway trip. Owing to the combined VRP-PTR formulation, each railway trip is allowed to reschedule its departure time from the station, if necessary. The results demonstrate the model’s potential as a tactical planning tool for optimizing shared mobility routes and synchronizing their services with public transport to meet passenger demand.