Timing of Train Disposition: Towards Early Passenger Rerouting in Case of Delays

Passenger-friendly train disposition is a challenging, highly complex online optimization problem with uncertain and incomplete information about future delays. In this paper we focus on the timing within the disposition process. We introduce three different classification schemes to predict as early as possible the status of a transfer: whether it will almost surely break, is so critically delayed that it requires manual disposition, or can be regarded as only slightly uncertain or as being safe. The three approaches use lower bounds on travel times, historical distributions of delay data, and fuzzy logic, respectively. In experiments with real delay data we achieve an excellent classification rate. Furthermore, using realistic passenger flows we observe that there is a significant potential to reduce the passenger delay if an early rerouting strategy is applied

Sensitivity Analysis and Coupled Decisions in Passenger Flow-Based Train Dispatching

Frequent train delays make passenger-oriented train dispatching a task of high practical relevance. In case of delays, dispatchers have to decide whether trains should wait for one or several delayed feeder trains or should depart on time. To support dispatchers, we have recently introduced the train dispatching framework PANDA (CASPT 2015). In this paper, we present and evaluate two enhancements which are also of general interest. First, we study the sensitivity of waiting decisions with respect to the accuracy of passenger flow data. More specifically, we develop an integer linear programming formulation for the following optimization problem: Given a critical transfer, what is the minimum number of passengers we have to add or to subtract from the given passenger flow such that the decision would change from waiting to non-waiting or vice versa? Based on experiments with realistic passenger flows and delay data from 2015 in Germany, an important empirical finding is that a significant fraction of all decisions is highly sensitive to small changes in passenger flow composition. Hence, very accurate passenger flows are needed in these cases. Second, we investigate the practical value of more sophisticated simulations. A simple strategy evaluates the effect of a waiting decision of some critical transfer on passenger delay subject to the assumption that all subsequent decisions are taken according to standard waiting time rules, as usually employed by railway companies like Deutsche Bahn. Here we analyze the impact of a higher level of simulation where waiting decisions for a critical transfer are considered jointly with one or more other decisions for subsequent transfers. We learn that such "coupled decisions" lead to improved solution in about 6.3% of all considered cases

Connection Dispatching - an Algorithmic and Visual Support for the Dispatcher

Securing connections in public transport is a mean to raise travellers' satisfaction and make their trips more convenient. Nevertheless, securing connections affects the trips of other travellers and therefore is not always the best solution regarding the complex train network.Thus, dispatching connecting trains is a complex task that demands special knowledge about the railway network, travellers, local situations and conditions, the schedule, rolling stock circulations, employees' duty rosters and rules concerning the dispatching process. Furthermore, the topic becomes more relevant recently as the traffic on European railway networks grows more complex whilst the demand for a proper connection dispatching on the part of travellers as well as the authorities rises. To further improve this complex task, a decision support for the dispatcher is desirable. We focus on methods to (visually) support the dispatcher in his daily work. A mean to achieve a better connection dispatching is the detection and display of conflicts. Detected conflicts are evaluated and prioritized. With the results of these processes, the connection conflicts are displayed in a proper and easy-to-catch way. Furthermore, we are investigating ways to automate conflict resolution routine processes. Here, many side conditions regarding the German railway's system of rules have to be taken into account. Also, we consider the whole dispatching process including the rejection of a connection and referencing to alternative possibilities for a connection request. The developed solution is tested in the Railway Operations Centre Darmstadt. Possible improvements are verified in cooperation with the (connection) dispatcher to assure an acceptance of the developed tools by the future user. The results of our research are designed such that algorithms can be directly implemented in the productive system of the German railway dispatching environment

Robustness as a Third Dimension for Evaluating Public Transport Plans

Providing attractive and efficient public transport services is of crucial importance due to higher demands for mobility and the need to reduce air pollution and to save energy. The classical planning process in public transport tries to achieve a reasonable compromise between service quality for passengers and operating costs. Service quality mostly considers quantities like average travel time and number of transfers. Since daily public transport inevitably suffers from delays caused by random disturbances and disruptions, robustness also plays a crucial role. While there are recent attempts to achieve delay-resistant timetables, comparably little work has been done to systematically assess and to compare the robustness of transport plans from a passenger point of view. We here provide a general and flexible framework for evaluating public transport plans (lines, timetables, and vehicle schedules) in various ways. It enables planners to explore several trade-offs between operating costs, service quality (average perceived travel time of passengers), and robustness against delays. For such an assessment we develop several passenger-oriented robustness tests which can be instantiated with parameterized delay scenarios. Important features of our framework include detailed passenger flow models, delay propagation schemes and disposition strategies, rerouting strategies as well as vehicle capacities. To demonstrate possible use cases, our framework has been applied to a variety of public transport plans which have been created for the same given demand for an artificial urban grid network and to instances for long-distance train networks. As one application we study the impact of different strategies to improve the robustness of timetables by insertion of supplement times. We also show that the framework can be used to optimize waiting strategies in delay management

Rail Privatisation: The Practice – An Analysis of Seven Case Studies

After a brief description of the proposals for rail privatisation in Great Britain, this paper contrasts these with the proposals and experience in other countries around the world. The proposals and experience in other countries contain some elements of the British proposals, however, the 'open access' element that features strongly in the British proposals has never been experienced on any significant scale elsewhere. In conclusion, experience elsewhere may shed light on the likely outcome of some aspects of the British proposals, but other aspects such as 'open access' and vertical separation are still unknowns

Robustness Tests for Public Transport Planning

The classical planning process in public transport planning focuses on the two criteria operating costs and quality for passengers. Quality mostly considers quantities like average travel time and number of transfers. Since public transport often suffers from delays caused by random disturbances, we are interested in adding a third dimension: robustness. We propose passenger-oriented robustness indicators for public transport networks and timetables. These robustness indicators are evaluated for several public transport plans which have been created for an artificial urban network with the same demand. The study shows that these indicators are suitable to measure the robustness of a line plan and a timetable. We explore different trade-offs between operating costs, quality (average travel time of passengers), and robustness against delays. Our results show that the proposed robustness indicators give reasonable results

Technology assessment of future intercity passenger transporation systems. Volume 1: Summary report

Technical, economic, environmental, and sociopolitical issues associated with future intercity transportation system options were assured. Technology assessment was used as a tool to assist in the identification of basic research and technology development tasks that should be undertaken. The emphasis was on domestic passenger transportation, but interfaces with freight and international transportation were considered