Integrating Passenger and Freight Transport in Demand-Responsive Systems: A Novel Agent-Based Modelling Approach

Integrating passenger and freight transport within a single system can enhance the profitability and sustainability of demand-responsive transport services, particularly in low-demand or rural areas. This study proposes a model in which low-capacity vehicles serve both passengers and parcels, prioritizing passenger trips while scheduling deliveries during vehicle idle times. Using an agent-based simulation in a synthetic environment, the analysis evaluates the trade-offs between passenger service quality, delivery reliability, and operator profitability. By varying the number of parcels and the flexibility of passenger time windows, the study identifies operational conditions that optimize system efficiency. Results show that moderate parcel volumes (i.e., 100 parcels/day) yield limited passenger discomfort, with 2–5% increase in travel times with respect to the passenger-only DRT service, while maintaining high passenger and delivery acceptance rates ('92%). A monetary compensation mechanism is proposed, redistributing the operator’s net profit (derived from avoided conventional delivery costs) among passengers as travel discounts. This incentive ensures user acceptance while supporting integrated service viability. The findings highlight the potential of passenger-freight integration to increase cost-efficiency and promote sustainable urban logistics in low-demand areas.