Different look into alternatives in railway projects : development of a decision support system to facilitate selection of alternatives by evaluating railway timetables using performance indicators

Katstra, A.W. (2015) Different look into alternatives in railway projects : development of a decision support system to facilitate selection of alternatives by evaluating railway timetables using performance indicators.

Abstract:The Dutch railway network is in the top three of highest utilized networks within Europe. In the most positive scenarios, demand forecasts for railway transport in the Netherlands show further growth between 2011 and 2020 for both passenger and freight transport of 27% and 107% respectively. Budgets for extending the infrastructure are limited. For many years the railway infrastructure and operating timetable have been optimized to deal with an increasing number of trains running on the same rail infrastructure. It has proven di�cult to determine the impact of new infrastructure or a new timetable on the feasibility and robustness of operating trains. ARCADIS detects a shift in their clients' requests from calculating the minimum interval time between two train services towards a more extensive analysis of the impact of infrastructure modifications on the feasibility of operating the timetable. Currently, analysing the operability for infrastructure alternatives on a specific timetable is a time consuming process, taking up to several weeks. The alternative selection processes often do not include secondary processes like shunting movements, and transitions between peak-hour and o�-peak timetables. Therefore, ARCADIS has developed a prototype model to automate steps in the evaluation of infrastructure alternatives and to implement the UIC 406 (2004a) methodology. UIC 406 is a widely accepted methodology to calculate the occupation time rate using the concept of timetable compression. However, other indicators are required to evaluate and select alternatives. The above leads to the following research goal: to facilitate the selection of alternatives in railway infrastructure or timetabling projects by developing and implementing a decision support system which uses indicators and the UIC 406 methodology to evaluate timetable scenarios. In this research, a literature review and interviews are used to gain information about the decision making process and to determine the indicators required to select alternatives. Two products are the outcome of this research: (1) a model to develop a passive decision support system to facilitate the selection of alternatives in infrastructure and timetable projects based on indicators and (2) an application tool that implements the designed decision support system and can support the decision making processes The model is capable of using headway times to evaluate a timetable realistically in a matter of seconds. The model describes the steps of the evaluation process for an infrastructure or timetable proposal, through the use of simulation software to calculating the follow-up times and the model uses that to calculate the indicators. Those indicators are an important aspect against which a timetable can be evaluated. The following four indicators are important in evaluating a timetable based on previous research into this subject by Schittenhelm (2013) and the interviews conducted with stakeholders during this research: (a) the occupancy time rate, calculated by using the UIC 406 methodology. In this research, the methodology is extended by calculating the occupation time rate per hour. (b) the heterogeneity of a timetable, calculated by �nding the variation in headway time interval and speed with the method provided by Landex (2007). (c) the degree of deviation from timetable planning rules, calculated by comparing the scheduled departure times with the earliest departure time according to the minimum headway time. (d) the stability of the timetable during operation: in this research a methodology is developed that calculates the e�ects of disturbance to a timetable/infrastructure scenario. The indicator is a ratio between the input disturbance and the amount of disturbance that is transferred to subsequent trains. The model contains three controls which allow the end-user to change parameters and to see the effects of those parameters on the output. These controls are (1) scenario selection, (2) level of aggregation output (1h, 2h, 24h), and (3) the running time margin. The application tool shows that it is capable of supporting and speeding up the selection of alternatives by providing three primary checks to the alternative: the occupation time rate, the stability of the timetable, and a check whether the proposed timetable will �t. Due to the nature of this application, this model allows a very exible way of testing the location of secondary processes in the timetable as the relation between the secondary processes and the primary process only needs to be calculated once. The stability indicator used in the application enables the end-user to see the e�ect of changing the distribution of margin between trains in the timetable. Therefore, a timetable with a more uniform distributed margin will be able to withstand more disturbances without transferring delays to subsequent trains. The output of the application uses modules to display the information, which allows for quick customization depending on the requirements of the end-user and type of project. In future research, the indicators should be veri�ed outside the Netherlands and applicability of the sensitivity-based stability indicator in a wider context should be further investigated. So far, the model has been applied to theoretical test cases. Further validation should be done by applying the tool to real-life projects, providing cases for analysis.
Item Type:Essay (Master)
Faculty:ET: Engineering Technology
Subject:56 civil engineering
Programme:Civil Engineering and Management MSc (60026)
Link to this item:http://purl.utwente.nl/essays/67539
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