The efficiency of ports is greatly influenced by the interaction between the port’s internal road and rail networks. This thesis presents a System Dynamics simulation model, developed in Vensim PLE, with the goal of understanding these interdependencies, identifying critical bottlenecks, and analyzing the capacity of a port in Northern Italy to withstand disruptions and demand growth. The work will primarily describe the model related to the road traffic, and will subsequently analyze the intersections with the railway. The key findings demonstrate that these conflict points emerge as critical sources of inefficiency along with shared sections of the network, which lead to significant backpressure and a cascading delay that propagates throughout the whole network, causing congestion.