Two- Echelon Vehicle Routing Problem with Trucks and Drones

Over the years, the Vehicle Routing Problem (VRP) has been extensively studied. As real-world scenarios and technol-ogy evolve, researchers are increasingly integrating drones with trucks, leading to the development of the Two-Echelon Vehicle Routing Problem (2EVRP). The 2EVRP involves dividing the route plan into two segments: the first echelon operated by trucks and the second by drones. With the introduction of lightweight, cost-effective delivery solutions like drones, the 2EVRP faces challenges such as limited drone battery life and adherence to public safety policies. This survey examines the literature on traditional exact and heuristic algorithms alongside contem-porary machine learning approaches, including supervised and reinforcement learning methods. Additionally, we review current real-world applications of drone delivery. Finally, we highlight several future research directions for 2EVRP with truck and drone collaborations.