Cost efficiency of mobile warehouse based last-mile delivery: A comparative analysis of delivery vehicles and facility location strategies

The increasing cost and environmental impact of last-mile home delivery have intensified interest in alternative urban logistics configurations. Mobile warehouses (MWs), which act as temporary urban micro-depots enabling two-echelon delivery, offer potential reductions in last-mile travel distance and support the use of low-emission vehicles. However, their economic viability remains insufficiently understood. This study evaluates the cost efficiency of MW-based last-mile delivery systems under alternative vehicle technologies and facility location strategies. A unified analytical framework integrating facility location optimization, network-based routing, and cost-per-parcel modeling is developed. Two classical location models such as k-center and p-median, used to solve distance- and time-based objectives, are applied to determine optimal MW placements. The resulting configurations are evaluated for three secondary delivery vehicle technologies: electric cargo bikes, electric vans, and diesel vans. The analysis is conducted using real-world delivery demand data from two mid-sized Swedish cities. Results show that MW deployment reduces delivery distances and times but increases cost per parcel under low-demand conditions due to additional operational overhead. Electric vans achieve the lowest cost in low MW-density configurations, while electric cargo bikes become competitive only at higher MW densities and under efficiency-oriented location strategies. Sensitivity analysis reveals that demand density and MW utilization are the dominant drivers of cost competitiveness, whereas energy price variation has a limited effect. The findings indicate that MW-based delivery systems are economically viable primarily in high-density, spatially clustered demand environments, offering practical guidance for logistics operators and urban freight planners. The results support evidence-based decisions on when MW deployment, vehicle electrification, and multi-stop consolidation strategies are economically justified in urban logistics planning.