Considering a dynamic impact zone for real-time railway traffic management
mode - rail, place - europe, technology - intelligent transport systems, operations - scheduling, planning - methods
Conflict prevention, Dispatching, Traffic management system, Real-time scheduling
In a railway system, a conflict occurs when two trains require the same part of the infrastructure at the same time. Currently, such conflicts are typically resolved manually by experienced dispatchers. However, it is impossible for them to fully anticipate the impact of their actions on the entire network. This paper proposes a conflict prevention strategy which focuses only on the relevant part of the network and traffic and, consequently, proposes a solution for that part only. The proposed strategy first looks for possible rerouting options by using an optimization model. If no solution is found, a solution based on delaying one of the trains is required. This retiming/reordering heuristic uses information from an offline calculation, for determining related conflicts that frequently occur. In this way, a so-called dynamic impact zone is created online for each conflict. When deciding which train to delay, the potential conflicts and the incurred delays of all trains in this dynamic impact zone are taken into account.
The performance of this new Conflict Prevention Strategy is compared to a common dispatching strategy, other heuristics, and an exact method. Extensive experiments on a large part of the Belgian railway network show that by considering this dynamic impact zone the total delay can be decreased by at least 67% compared to the basic First Come, First Served decision rule. Moreover, the dynamic impact zone has a reasonable size and scales well to large networks as only the relevant conflicts and their expected consequences are considered. This makes our Dynamic Impact Zone heuristic very fast. The computation time for returning a resolution to a conflict with the proposed conflict prevention strategy is, for 95% of the conflicts, less than two seconds, and at most 26 s, including the creation of the dynamic impact zone of the conflict.
Permission to publish the abstract has been given by Elsevier, copyright remains with them.
Van Thielen, S., Corman, F., & Vansteenwegen, P. (2018). Considering a dynamic impact zone for real-time railway traffic management. Transportation Research Part B: Methodological, Vol. 111, pp. 39-59.