Simulation of railroad terminal operations and traffic control strategies in critical scenarios

Railroad terminals contribute to the competitiveness of intermodal transport and play an important role in the transport chain to achieve seamless cross-modal processes, because they must guarantee a fast, safe, and efficient transfer of intermodal loading units. The equipment required, such as gantry and mobile cranes can be critical to the terminal process. However, numerous cranes cannot be designated to guarantee a high level of redundancy, because of their relevant cost. This paper presents a micro-simulation approach for evaluating the resilience of typical railroad terminals in a critical scenario, such as the temporary unavailability of a gantry crane. Resilience can be defined as the capability of the system to recover its functionality despite a disruption and a gating strategy is proposed in this case to maintain the desired level of service inside the terminal. Therefore, this traffic control strategy is investigated to ascertain its ability in enhancing the terminal resilience when a disruption occurs in a process. The proposed simulation method is not only used for performing a typical sensitivity analysis under disturbed conditions, but also for assessing the flexibility of the simulated terminal. A comparison is performed for a baseline traffic scenario in equilibrium conditions by setting equal average values for the arrival and service rates, thereby exploring the operation of the infrastructure near its capacity. In the simulation tool, the relevant features of the typical phases of the internal process are represented, and the traffic flow data of truck arrivals are disaggregated based on specific operations using dedicated service lines. To compare the modeled scenarios, some quantitative key performance indicators (KPIs) are selected and quantified in terms of quality and energy impacts.