Netherlands Railways Research Articles

Train suicides in The Netherlands

Background Little is known about train suicide and factors influencing its prevalence. This study tests the hypotheses that railway density, railway transportation volume, familiarity with railway transportation and population density contribute to train suicide. It also tests the relationship between train suicide and general population suicide and examines the prevalence and the characteristics of high-risk locations and their contribution to the grand total of train suicides. Methods Trends in train suicides were compared with trends in railway track length, train kilometres, passenger kilometres and national suicide figures over the period 1950–2007. The geographical distribution over the national network over the period 1980–2007 was studied. Data were obtained from The Netherlands Railways, Prorail and Statistics Netherlands. Results 1. The incidence of train suicides is unrelated to railway parameters. 2. Being familiar with railway transportation as a passenger is not a contributory factor. 3. Train suicide rates are unrelated to regional population density. 4. The incidence of train suicides parallels that of general population suicides. 5. Half of the train suicides took place at a limited number of locations, the most important of which were situated within a village or town and were close to a psychiatric hospital. Limitations Most conclusions are based on correlational relationships between variables. Conclusions 1. Train suicide trends reflect trends in general population suicides. 2. Increased train transportation does not lead to more train suicides. 3. The prevention of train suicide at high-risk locations (HRLs) in built-up areas and near psychiatric hospitals deserves first priority.

The New Dutch Timetable: The OR Revolution

In December 2006, Netherlands Railways introduced a completely new timetable. Its objective was to facilitate the growth of passenger and freight transport on a highly utilized railway network and improve the robustness of the timetable, thus resulting in fewer operational train delays. Modifications to the existing timetable, which was constructed in 1970, were not an option; additional growth would require significant investments in the rail infrastructure. Constructing a railway timetable from scratch for about 5,500 daily trains was a complex problem. To support this process, we generated several timetables using sophisticated operations research techniques. Furthermore, because rolling-stock and crew costs are principal components of the costs of a passenger railway operator, we used innovative operations research tools to devise efficient schedules for these two resources. The new resource schedules and the increased number of passengers resulted in an additional annual profit of €40 million ($60 million); the additional revenues generated approximately €10 million of this profit. We expect this profit to increase to €70 million ($105 million) annually in the coming years. However, the benefits of the new timetable for the Dutch society as a whole are much greater: more trains are transporting more passengers on the same railway infrastructure, and these trains are arriving and departing on schedule more than they ever have in the past. In addition, the rail transport system will be able to handle future transportation demand growth and thus allow cities to remain accessible to more people. Therefore, we expect that many will switch from car transport to rail transport, thus reducing the emission of greenhouse gases.

K-Shortest routing of trains on shunting yards

We consider the problem of designing algorithmic support for k-best routing decisions in train shunting scheduling. A study at the Netherlands Railways revealed that planners like to interact with the solution process of finding suitable routes. Two types of interaction were required: the possibility of assigning specific tracks to a route and of preventing the assignment of specific tracks to a route. The paper develops insights in the structure of the cost matrix in this k-best optimization problem. These dominance results are used in a two stage k-shortest path algorithm to support this task of the shunting planners. The solution approach determines the optimal sequence of the tracks that manually have been added to the route and determines the k shortest paths in this network. The approach is implemented in a prototype of a support system for shunting planners. The required calculation times for practical instances of the problem with varying numbers of alternative solutions (k ≤ 8) and intermediate tracks (m ≤ 5) are between 0.1 and 1.4 s. These calculation times are acceptable to provide adequate support to the planners of these shunting yards.

Cognition, tasks and planning: supporting the planning of shunting operations at the Netherlands Railways

One of the issues in planning research and planning practice are their apparent incompatibility. Various fields study aspects of planning, but too little is jointly used in practice. Starting from the human planner as a cognitive system, we elaborate the mixed initiative approach, in which we combine three fields: cognitive aspects of the task of the human planner, computer support, and algorithms. In this article, we argue that algorithms should be created for planners’ subtasks rather than for planning problems. We demonstrate this in a prototype that we developed for a shunting planning project we are involved in at the Netherlands Railways [Nederlandse Spoorwegen (NS)]. In this project, a task analysis resulted in a planning support system with bottom up designed scheduling algorithms.

DESIGNING A MULTI-AGENT SYSTEM FOR COOPERATIVE TRAIN DISPATCHING

In the Netherlands railway traffic is currently highly dense and during operations timetable perturbations occur frequently. A recent trend is to increase the throughput in congested areas by designing flexible timetables, and solving route conflicts between different train types in real-time. This paper presents a method for real-time train conflict resolution by cooperative, multi-agent negotiation. In each dispatching area, a dispatch agent, as leader, builds the negotiation set of alternative solutions and transport operator agents negotiate using the Monotonic Concession Protocol. The timetable modifications suggested by the negotiation can efficiently solve conflicts considering the objectives of authority and train companies.

Planners and their cognitive maps: An analysis of domain representations using multi dimensional scaling

We expected planners working on the planning problems at a particular department for many years to have similar ideas about their work domain. However, we found the opposite when we analyzed the results of an extensive knowledge elicitation study we performed on 25 planners working in the rolling stock and rolling staff planning department of the Netherlands Railways (in Dutch: NS). The planners were asked to model their domain by means of card sorting and graph-positioning methods using domain-related objects and relations. When we applied multi dimensional scaling to the outcome of this study, we found large differences in the individual cognitive maps thus created. In this article, we describe the analyses and discuss our findings about planners’ cognitive maps. These maps may have implications for the organization of planning in general, for training of planners, and for software design.

A Branch-and-Cut Approach for Solving Railway Line-Planning Problems

An important strategic phase in the planning process of a railway operator is the development of a line plan, i.e., a set of routes (paths) in a network of tracks, operated at a given hourly frequency. We consider a model formulation of the line-planning problem where total operating costs are to be minimized. This model is solved with a branch-and-cut approach, for which we develop a variety of valid inequalities and reduction methods. A computational study of five real-life instances based on examples from Netherlands Railways (NS) is included.

Reinventing Crew Scheduling at Netherlands Railways

In 2001, the 6,500+ drivers and conductors of the Dutch railway operator NS Reizigers were very dissatisfied with the structure of their duties, which led to nationwide strikes. However, the successful application of an operations research model supported the development of an alternative set of scheduling rules. This alternative set of rules, called Sharing-Sweet-and-Sour, satisfied the drivers’ and conductors’ requests for more variety in their duties and improved the railway operator’s punctuality and efficiency. The application of the operations research model cut personnel costs by about $4.8 million (1.2 percent) per year. Moreover, we showed that the railway operator could even reduce personnel costs by over $7 million per year.

A New User Interface For The Train Traffic Control System

The number of trains is increasing rapidly to accommodate the transport capacity required. The Netherlands Railways manages an average of 6000 trains per day, which results in highly intensive usage of the infrastructure. This paper describes how the routing process has changed over the last decade, shifting from manual route setting on huge switchboards to automatic routing using computer systems. If all trains are running according to the published timetable, there is little or no intervention by the train traffic controller. When there are no disrupting factors, almost all routes can be set automatically by the computer systems. However even relatively small disturbances can lead to a large disruption if not handled appropriately. The train traffic controller must therefore be able to handle all potential conflicts early enough to keep the rout schedule up to date and free of conflicts. To perform this task effectively, the train traffic controllers need to a user interface with functionality that supports their primary tasks. Nowadays user interfaces are focused on controlling the infrastructure (e.g., points and signals). They support the setting of routes for each individual train movement (e.g., arrival and departure). A new approach is to focus more on the predicted train process on the open track and on the station tracks. Based on the timetable and the actual situation, the new user interface shows the train traffic controller the predicted train and potential conflicts.

Returns to Density in Operations of the Netherlands Railways

Rail cost function analysis has been a popular topic in the (empirical) economics literature over the past decades. Most studies find increasing returns to density for rail companies. The results can, however, be quite diverse. Results for the Dutch National Railway company (NS), for instance, indicate very strong increasing returns to density Andrikopoulos and Loizides, 1998) or decreasing returns to density (Preston, 1994). Using the, to our knowledge, most comprehensive dataset for the NS, this paper estimates a translog variable cost function for the NS. While the returns to density parameter shows increasing returns, like so many other papers, the calculated standard errors shows that the null hypothesis of constant returns may not be rejected.

Shunting of Passenger Train Units in a Railway Station

In this paper we introduce the problem of shunting passenger train units in a railway station. Shunting occurs whenever train units are temporarily not needed to operate a given timetable. We discuss several aspects of this problem and focus on two subproblems. We propose mathematical models for the problem and both subproblems, one of which is solved with a solution method based on column generation. Furthermore, we introduce a new efficient and speedy solution technique for pricing problems in column generation algorithms. Finally, we present computational results based on real-life instances from Netherlands Railways.

Why railway passengers are more polluting in the peak than in the off-peak; environmental effects of capacity management by railway companies under conditions of fluctuating demand

Given the difference between peak and off-peak occupancy rates in public transport, the average emission per traveller kilometre is lower in the peak than during the off-peak period. However, in this paper it is argued that it is much more fruitful to analyse environmental effects in marginal than in average terms. The issue appears to depend on capacity management policies of public transport suppliers that are facing increases in demand both during the peak and off-peak period. A detailed analysis of capacity management of the Netherlands Railways reveals that the off-peak capacity supply is mainly dictated by the demand levels during the peak period. Topics that receive attention in the analysis are the effects of frequency increases and size of vehicle increases on environmental effects. Also environmental economies of vehicle size are taken into account in the analysis. The main conclusion is that the marginal environmental burden during the peak is much higher than is usually thought, whereas it is almost zero at the off-peak period. Thus, one arrives at a pattern that is entirely reversed compared with the average environmental burden: peak passengers are more polluting than off-peak passengers. The conclusion is that policies based on average environmental performances would lead to misleading conclusions.

Optimal pricing in railway passenger transport: theory and practice in The Netherlands

This study tries to establish the link between the well-developed economic theory of optimal pricing, and recent empirical results concerning price elasticities of demand and marginal cost estimates for The Netherlands Railways. The ex post determination of Ramsey coefficients confirms that peak hour pricing is dominated by the aim of welfare maximization, while off-peak fares largely correspond to the profit-maximizing objective. It is argued that tariff differentiation according to track offers scope for a budget-neutral welfare improvement, and that a price-elastic off-peak market implies that lower off-peak fares result in a Pareto-improvement.

Seasonal changes in 24-h patterns of suicide rates: a study on train suicides in The Netherlands

Background: Annual patterns in suicide rates, peaking near the summer solstice, are well documented. It has been suggested that day length or total hours of sunshine has an impact on suicide rates. If these environmental factors are involved, we would expect changes in the daily pattern of suicide rates to occur over the year. To test this hypothesis, the 24-h patterns of suicide rate were investigated as a function of time of year. Method: Detailed information about the exact time of suicides in The Netherlands is only available for train suicides. Therefore, information concerning age, sex, time and place of occurrence of all verified train suicides over 15 years in The Netherlands ( n=2830) was obtained from The Netherlands Railways archives. Results: Daily patterns in train suicides show systematic variations of two kinds. First, independently of time of year, suicide rates at night drop to about 10% of their daytime values. Second, there are two daily peaks in the patterns which shift their timing over the year, with one peak occurring shortly after sunset, and the other one consistently occurring 9–10 h earlier. Both peaks shift with the 5.5-h shift in sunset time. Limitations: Train suicidal behaviour may not represent fatal suicidal behaviour in general. Conclusions: There are pronounced and systematic daily variations in train suicide rates in The Netherlands. One of these is related to clock time, the others are related to the light–dark cycle. The consistency of the patterns suggests a strong environmental influence on train suicidal behaviour. Research on 24-h patterns of suicide rates should control for time of year.

An aggregate capacity estimation model for the evaluation of railroad passing constructions

The Netherlands Railways operates a double tracked intensively used network of railroads. To expand the transportation capacity, each year a number of infrastructure expansions are considered. The evaluation of these expansions is traditionally done by establishing a set of detailed timetables that serve the forecasted transportation demand and that can be executed with the proposed infrastructure expansion. However, the development of a detailed timetable is a very time consuming process, and therefore leaves little opportunity for comparing many alternatives. In this paper, we present and test an aggregate model that can be used to single out the most promising investment alternatives in the railroad infrastructure, specifically passing constructions. The aggregate model provides the user with insight into the ranking of the various alternatives and additionally gives a relative insight into the theoretical capacity of the proposed infrastructure change.

Automatic Conflict Detection And AdvancedDecision Support For Optimal Usage Of RailwayInfrastructurePurpose And Concepts

This paper describes conflict detection and advanced decision support in the control of route setting operations, leading to optimal usage of railway infrastructure. Such a system is currently in development at the Netherlands Railways. By accurately forecasting train movements, conflicts can be detected in advance. A decision support module gives a what-if scenario, presenting alternative options to solve the selected conflict. Available measures are weighed by the system, using a cost function, and presented to the operator sorted on overall quality. Using Operations Research Techniques a generic system is obtained, giving reliable evaluations of the problem in short response times.

Computer Aided Railway Engineering

The Netherlands Railways currently makes use of a number of distinct types of train control systems. All these systems are based on generic application software supplemented by location-specific configuration data describing the infrastructure topography. The scale of this data is such that manual input is unrealistic. A framework of computer-based tools has therefore been developed to support the engineering of the configuration data. This paper describes this framework.

Automatic Conflict Detection And AdvancedDecision Support For Optimal Usage Of RailwayInfrastructure: Prototyping And Test Results

The Netherlands Railways currently uses a computer-controlled route setting based on a route setting scheme. Route management has shifted from dispatching towards planning and supervising routes. Early conflict detection and decision support (CD/DS) is needed to support this new working method. The CD/DS system effectively adjusts the route setting scheme in advance when, for example, a delayed train will cause a conflict. This paper highlights prototyping results with this system, its architecture and purposes and results of real life tests. The tests were performed to ensure the feasibility, reliability and accuracy of train movement predictions and conflict detection. The purposes and concepts of the CD/DS are discussed by Stolk [2].

Routing trains through railway stations: complexity issues

In this paper we consider the problem of routing trains through railway stations. This problem occurs as a subproblem in the project DONS that is currently being carried out under the supervision of Railned and Netherlands Railways. The project DONS involves the determination of the required future capacity of the Dutch railway infrastructure.In this paper we focus on the computational complexity of the problem of routing trains through railway stations. After an extensive description of the problem, we show that only a subset of the sections and routes of a railway station needs to be taken into account. Then we show that the routing problem is NP-complete as soon as each train has three routing possibilities. However, if each train has only two routing possibilities, then the problem can be solved in an amount of time that is polynomial in the number of trains. Furthermore, if the layout of the railway station is fixed, then the latter is also the case for the problem of finding an assignment of a maximum number of trains to routes that is feasible from a safety point of view. This result can be extended to the case where coupling and uncoupling of trains, certain service considerations, and a cyclic timetable have to be taken into account.

INDUSTRIAL NOISE IN RAILWAY YARDS; THE PROBLEM OF SQUEAL NOISE

The Netherlands Railways have great problems in satisfying the noise limits in railway yards. A short description of the Dutch noise legislation for railways is given. One of the noise sources in railway yards is squeal noise. An investigation has been started in order to reduce this noise. Measurements were taken at a small-radius curve, part of which was sprayed with water. The results of these measurements were good: reductions of 6–11 dB in the equivalent noise levels were achieved.