Evaluating Disturbance Robustness of Railway Schedules

Abstract

Railway traffic is operated according to a detailed schedule, specifying for each train its path through the network plus arrival and departure times at its scheduled stops. During daily operations, disturbances perturb the plan and dispatchers take action in order to keep operations feasible and to limit delay propagation. This article presents a thorough assessment of the possible application of an optimization-based framework for the evaluation of different timetables and proactive railway traffic management over a large network, considering stochastic disturbances. Two types of timetables are evaluated in detail: " regular" and " shuttle" timetables. The former is the regular plan of operations for normal traffic conditions, while the latter plan is designed to be robust against widespread disturbances, such as adverse weather, track blockage, and other operational failures. A test case is presented on a large Dutch railway network with heavy traffic, for which we compute by microsimulation detailed train movements at the level of block signals and at a precision of seconds. When comparing the timetables, a trade-off is found between the minimization of train delays, due to potential conflicts and due to delayed rolling stock and crew duties, and the minimization of passenger travel time between given origins and destinations.

A Review of Online Dynamic Models and Algorithms for Railway Traffic Management

“…The majority of approaches reviewed consider those control actions in a sequential manner, generally starting from global routing. An example, global routing decision, can be taken to avoid a blocked area, local rerouting can be then chosen to spread capacity usage at bottleneck stations; orders can be decided, and all those orders result in times associated to train operations [19]. In addition, the opposite process can be followed, i.e., first computing a set of passing times and then finding a feasible route assignment; this was done, for instance, in [6] proposed for the competition [42].…”

Increasing Robustness by Reallocating the Margins in the Timetable

“…The aggregation concept introduced by Murali et al [23] is adopted to reduce the computational effort for the real-world case. In literature, Corman et al [25] used the same concept for railway traffic management. The basic concept of aggregation is the combination of a sizeable portion of the network into a single node in the graph.…”

PULSim: User-Based Adaptable Simulation Tool for Railway Planning and Operations

“…If the robustness and stability of a timetable are matters of concern, a so-called operational simulation can be carried out, in which stochastic influences will be introduced. The robustness and stability of the investigated timetable can be derived according to statistical indicators, which are calculated based on the outputs of several rounds of simulation with different randomly generated influences [7,8]. In the area of capacity research, system performance can be evaluated through simulating randomly generated timetables for a certain operating program, a process which can, in addition, identify bottlenecks and determine the quality of an operating program [9].…”