Towards sustainable and equitable accessibility for rural communities: An optimization model for an integrated passenger and freight transportation system with parcel lockers

Transportation is vital for access to essential services such as healthcare and education. However, rural communities often struggle with inadequate transportation systems due to low population density, forcing individuals to depend on personal vehicles or transport modes that may pose safety risks, such as walking or hitchhiking. To address these challenges, we propose implementing an integrated passenger and freight transportation (IPFT) system, which transports people and goods on the same vehicle with dedicated capacities, utilizing public transportation and parcel lockers. Given that public transport vehicles are less occupied in rural areas than in urban areas, utilizing the free space in the vehicle for carrying small parcels presents a resource-efficient solution. To that end, we develop two models: While the first model determines the optimal number and location of bus stops and parcel lockers, the second one establishes public transport's route, schedule, and capacity allocations. Then, we compare our IPFT network optimization model with another model where passenger and freight services operate independently to demonstrate the added value of freight integration. The results indicate that the proposed model reduces the total operational cost and carbon emissions. Hence, by providing this service, rural residents may enjoy enhanced accessibility to essential services. Further, in the context of cultural sustainability, we delineate our findings and offer venues for future research.