Transportation systems modeling is a research field and methodological approach focused on creating abstract representations of transportation networks, their components, and the interactions within them. It investigates the behavior, performance, and dynamics of these systems under various conditions, employing mathematical, statistical, and computational techniques, including simulation and data analysis, to replicate and analyze real-world phenomena. Its significance lies in providing crucial tools for understanding complex transportation phenomena, predicting future states, evaluating planning alternatives, and informing policy decisions.