Multi-criteria integration of passenger and freight transport for sustainable last-mile delivery logistics

The first and last mile (FLM) transport for passengers and freight significantly contributes to overall pollution, transportation costs and energy consumption. Recent scientific reports at European level suggest that combining passenger and freight flows (commonly referred to as integrated transport) could be an effective strategy to promote sustainable and energy-efficient FLM transport. Public transportation usually covers most populated areas of the city, making it suitable for this kind of dual operation. Despite their potential, integrated systems have not been extensively explored. This study develops an algorithm that optimizes the location of dual-purpose stops within Bilbao’s bus network in Spain to facilitate such integrated operations through a combination of evolutionary algorithms. The real multi-objective optimization scenario proposed as a case study formulates and solves the problem of balancing the benefits and inconveniences of incorporating such a combined service. The design of the system’s operational aspects involves the integration of the real scenario service characteristics into the problem formulation, as well as an analysis of local planning documents. The system’s performance is assessed and compared to existing public transport and freight systems, considering the Pareto trade-off of two key factors for the design of the service: the impact of the integrated transport service on the passengers’ quality of service and the mileage required to deliver goods to their corresponding destinations. Our findings indicate that operational benefits and energy savings can be achieved gauging the level of inconvenience introduced in the passenger transportation service.