This paper deals with a collaborative train rerouting and rescheduling problem faced by traffic controllers at regional railway control centers. Typically, the railway network is divided into non-overlapping control areas. Each control center coordinates several control areas. The problem we consider arises when a perturbation (i.e., an unexpected, degraded operation) occurs and the timetable cannot be operated as planned. To minimize the impact of such a perturbation, e.g., to minimize delay propagation, measures as train rescheduling and rerouting can be applied. This problem is known in the literature as real-time Railway Traffic Management Problem (rtRTMP). Several approaches have been proposed to deal with it. Nevertheless, only few papers focus on the coordination of traffic management across different control areas.

In the approach we propose, for each control center, the real-time railway traffic management is hierarchically organized into two decision levels. At the lower level, dispatchers manage train schedules and routes in their own control areas. At the higher level, a coordinator ensures the compatibility of dispatchers' decisions over two or more areas. To optimize the overall system performance, the coordinator may impose constraints to dispatchers. Hereinafter, we will refer to the problems tackled at the lower and higher levels as dispatching and coordination problem, respectively.