A Bi-Objective Truck Traveling Salesman Problem With Drone and Boat Considering an Equity-Based Perspective in Disaster Relief Distribution

The distribution of disaster relief is a vital aspect of disaster response, which can reduce victim suffering during the postdisaster phase. Disaster relief distribution is a complex process, especially if available road access is damaged or blocked as a result of a disaster, such as a flood. Using trucks, drones, and inflatable boats can solve this problem efficiently because drones and boats can access shelter locations that are difficult to serve by conventional vehicles like trucks. However, efficient distribution does not guarantee that the distribution process will be fair, considering that humanitarian logistics focuses more on social aspects, such as equity, which differs from other types of logistics. Therefore, this study aims to develop equity-based bi-objective models for the truck-drone-boat routing problem, referred to as the bi-objective traveling salesman problem with drone and boat. Novel nonlinear and linear models for the truck-drone-boat routing problems are developed. This study also proposes a matheuristic-based method by combining an exact method and a heuristic, called an $\varepsilon$-constraint with a dynamic hill climbing-based method (EC-DHC) to solve the problem. The computational results of the case study and the generated datasets show that the method produces promising results, followed by providing valuable managerial implications for handling the flood disaster relief distribution problem.