Optimizing Drone Operations for Middle-mile Deliveries: Are We Ready for Real-World Deployment?

The use of drones for freight delivery has been extensively investigated in the context of last-mile logistics, with existing literature underlining potential benefits across several dimensions, from economic efficiency to reductions in CO2 emissions. However, it is not clear if these advantages also extend to longer routes and apply to middle-mile delivery (MMD). By relying on real-world data on freight transported between distribution and sorting centers of one of Italy’s major freight operators and proposing an optimization model dealing with drone location and flight scheduling, this study evaluates the operational feasibility of using drones for MMD. We consider three different variants of the model —namely, maximization of freight transported, maximization of the ground movements replaced by drones, and minimization of overall CO2 emissions— to evaluate the applicability of drones based on different objective functions. The results reveal that, while the current technical characteristics of drones are not yet sufficient to fully replace ground-based freight movements, they already offer opportunities for integration in specific segments. By applying the proposed model to a real-world MMD network in Central Italy, we found that drones can handle up to 31.6% of the total daily package demand, contributing to a reduction of up to 3.5% in current emission levels. These findings provide a preliminary instrument for operators and policymakers, highlighting the potential role of drones as a complementary solution within MMD, while also emphasizing the need for continued technological and regulatory advancements to fully realize their potential.