Urban distribution planning in humanitarian aid logistics

The frequency of disasters is increasing over time, resulting in the loss of life and property. Effectively managing humanitarian aid logistics activities is crucial to minimize the incurred losses. Therefore, appropriate distribution plans must be developed to rapidly meet the needs of disaster victims. When making decisions regarding vehicle routing for the distribution of humanitarian aid materials, uncertainties such as infrastructure damage caused by the disaster need to be taken into account. These damages can impede the delivery of necessary aid materials by large-tonnage vehicles. Considering these factors, it is necessary to establish an appropriate distribution network. The objective of this study is to propose a decision-support model for organizations engaged in humanitarian aid activities. In line with this objective, this study proposes a Mixed Integer Linear Programming (MILP) model for the Two Echelon Vehicle Routing Problem (2E-VRP) in humanitarian aid logistics. This model aims to minimize the total travel time. The accuracy and applicability of the model are demonstrated through an earthquake scenario example that could occur in the Kartal district of Istanbul province. The closure of roads after a disaster is taken into account. The problem at hand includes a heterogeneous vehicle fleet for distribution and incorporates pedestrians. Capacities, speeds, and progress capabilities of vehicles differ according to vehicle types. Due to the possibility of road closures, deliveries can be made to unreachable demand points through transfer points using pedestrians. The contribution of this study to the literature is its inclusion of different types of vehicles in the distribution fleet, suggesting different speeds and progress capabilities of vehicles on roads, and proposing the use of pedestrians for distribution. Through numerical analysis, an appropriate distribution method is determined, taking into account the probabilities of the designated vehicle tours not being closed, to minimize the total travel time. Thus, the focus is on real-life scenarios that can provide support to decision-makers. This proposed model will be coded with the help of IBM CPLEX computer program and analyzed in terms of fuel, time and vehicle type, and it will be tried to reach the optimum result for each objective function. The main purpose of this study is to compare the different results obtained from the scenario analysis of time, cost and fuel consumption variables by considering the possibility of road closure and including different vehicle types in the problem. In this model, in the first stage, the capacity, speed and routes of the loaded vehicles will be determined. Then, the capacity of the vehicle to be transferred and the speed and usability of these second-stage vehicles will be examined. In addition to these, the amount of emissions caused by the vehicles to be used will also be considered. The distance and road data to be used in the model will be obtained through the AFAD website.