Synchromodal ulaşım ağları tasarımı ve işletilmesi için ayrık-sürekli optimizasyon yaklaşımı

Modern supply chain systems have become mostly integrated and complex due to the constant pressure to improve their efficiency thresholds. In Europe, some of the important challenges including traffic congestion, carbon emission rates, intermodal transportation integration, the need for new infrastructure developments and maintenance of existing infrastructures as well as ensuring quality, reliability and efficiency of transportation and mobility services have always been a concern for the transportation systems. These challenges are emerging as an urgent issue and there are many visions and solution methodologies addressed by different stakeholders in the transportation domain. The main objective of this thesis is the elaboration, testing and validation of new models for the analysis, design, evaluation, and management of complex sustainable transportation activities. This thesis presents the multi-objective mixed-integer programming problem for integrating specific characteristics of synchromodal transportation (such as real-time planning and bundling of shipments). The problem includes different objective functions including the total transportation cost, travel time and CO2 emissions of proposed networks while optimizing the network structure. The traffic congestion, time-dependent vehicle speeds and vehicle filling ratios are considered in an integrated manner and computational results for different illustrative cases are presented with real data from the Marmara Region of Turkey. The defined non-linear model is converted into linear form and solved by using a customized implementation of the ϵ-constraint method for the multi-objective mixed-integer linear programming problem. Then, the analysis of Pareto solutions and sensitivity analysis of proposed mathematical models with different pre-processing constraints are summarized for decisions makers. It is shown that the synchromodal transportation model presented in this paper is very affective in determining transportation network structures and optimized planning and operation of these networks.