Optimality analysis of train platforming and routing with different interlocking modes

The train platforming and routing (TPR) problem is to decide train operations within stations after the network-wise train schedules are determined. A feasible TPR plan requires both platform and route conflict-free, where the avoidance of route conflict is controlled according to three interlocking modes. Although the TPR problem is widely studied, none of them did a serious investigation on the optimality impacts of different interlocking modes in the TPR. Therefore, this paper introduced and formulated a space–time version of TPR considering three interlocking modes and subsequentially conducted numerical experiments to analyze the optimality differences under each mode. Based on the experimental findings, engineering practical suggestions are also provided. In summary, the experiment results showed that both route-locking sectional-release and sectional-locking sectional-release modes significantly outperform the route-locking route-release mode. And among them, using the route-locking sectional-release mode can bring notable benefits on large stations with high-density volumes while using the sectional-locking sectional-release mode can always provide outstanding outcomes over various station and traffic settings.