Resilience-Inclusive Capacity Assessment for Railway Networks Under Virtual Coupling via Simulation

One of the fundamental problems in virtual coupling (VC) is improving the capacity by reducing the safe distance without compromising safety. From the resilience-inclusive perspective, the capacity can be controlled by the range of safe distance, which ensures that the gap between trains within the virtually coupled convoy is within the range of safe distance. By leveraging the spacing policy on the basis of relative braking distance for train traffic within the VC-enabled platoons, the resilience-inclusive capacity is defined as the minimum space occupation of all the platoons needed to complete the train service intention set, which involves two phases of VC (i.e., coupling and moving in a coupled platoon) and the multiplier effect for these two stages. In order to assess the VC-enabled capacity quantitatively via simulation, the general simulation framework, the steps for prioritizing shared common route sections (SCRSs), the flowcharts and associated steps for capacity estimation with nonhomogeneous fixed maximal braking/accelerating rates of train compositions (b/a), and the flowcharts and associated steps for capacity estimation with heterogeneous dynamic maximal b/a are proposed. At last, the proposed methods were verified on two typical case studies via the NetLogo platform. On average, VC strategies with dynamic fluctuation of maximal b/a reduced spatial occupation by 27.05% compared to those with fixed maximal b/a. And the clarified practical impact would enable more than 27% capacity redundancy for disruption absorption. The effectiveness of the proposed methods can offer significant guidance to decision-makers in capacity bottleneck identification and timetabling under VC-enabled conditions. It is worthwhile to investigate and further advance this study in the future.