DISTURBANCE MANAGEMENT TRAFFIC RAILWAY ABSTRACT With the increasing traffi c volumes in many rail- are diffi cult to identify and model. Moreover, the way networks and reports on capacity defi ciencies objectives of the disturbance management are va- RAILWAY TRAFFIC DISTURBANCE that result in insuffi cient punctuality and reliability, gue and partly unclear, and therefore it is also dif- the need for effi cient disturbance management fi cult to measure and evaluate the outcome of the MANAGEMENT solutions becomes evident. This thesis focuses on corresponding decision-making. solutions that aim to minimise the consequences Finally, a number of optimisation-based solution of disturbances for the various stakeholders and approaches with the purpose to facilitate for the specifi cally on methods for re-scheduling the traf- dispatchers and their decision-making has been fi c. Railway traffi c re-scheduling is a complex task developed. The performance and applicability with many infl uencing factors to consider and of the approaches have been evaluated for vari- multiple stakeholders with sometimes confl icting ous disturbance settings using data for parts of interests. This problem is typically handled manu- the Swedish railway network that currently ex- ally by traffi c dispatchers that have a very limited perience capacity defi ciencies. The evaluation has access to support systems to facilitate their de- identifi ed certain disturbances characteristics that Johanna Törnquist cision-making. This limitation hampers the possi- have a signifi cant infl uence on the disturbance pro- bilities to achieve sustainable and system-optimal pagation, and which in some cases complicate the decision-making and to provide the stakeholders re-scheduling procedure. Furthermore, the signifi - with reliable traffi c prognoses. cance of applying certain re-scheduling objectives We fi rst study how railway traffi c system users and their correlation with performance measures experience and are affected by the way the dis- has been analysed. The analysis shows e.g. that a turbances are communicated and handled by the minimisation of accumulated delays has a tenden- traffi c dispatchers. The results indicate that the cy to delay more trains than a minimisation of to- disturbance-related information provided by the tal fi nal delay or total delay costs. An experimental dispatchers is currently insuffi cient. The stakehol- study of the long-term effects when applying a li- ders need to acquire improved prognoses of their mited planning perspective has also been conduc- traffi c and immediate part of the network to in- ted. The results indicate that solutions which are ternally be able to minimise the negative effects of good on longer-term can be achieved despite the the disturbances. Furthermore, an analysis of the use of a limited planning horizon. In parallel to the disturbance management problem structure and optimisation-based approaches, an agent-based how the problem can be modelled is provided. conceptual model with emphasis on the interplay The analysis shows that there exist fundamental between the different components in the railway restrictions in the traffi c system that bounds the traffi c system has been proposed. Johanna Törnquist Johanna traffi c fl ow but also a large number of context- Keywords: Railway traffi c, Transportation, Re- dependent considerations such as sustaining cer- scheduling, Disturbance management, Decision tain connections or prioritising specifi c trains. The support systems. prevalence and feasibility of such considerations Blekinge Institute of Technology Doctoral Dissertation Series No. 2006:03 2006:03 ISSN 1653-2090 School of Engineering 2006:03 ISBN 91-7295-086-2 Railway traffic disturbance management Johanna Törnquist Blekinge Institute of Technology Doctoral Dissertation Series No 2006:03 ISSN 1653-2090 ISBN 91-7295-086-2 Railway traffic disturbance management Johanna Törnquist Department of Software Engineering School of Engineering Blekinge Institute of Technology SWEDEN © 2006 Johanna Törnquist Department of Software Engineering School of Engineering Publisher: Blekinge Institute of Technology Printed by Kaserntryckeriet, Karlskrona, Sweden 2006 ISBN 91-7295-086-2 Abstract With the increasing traffic volumes in many railway networks and reports on capacity deficiencies that result in insufficient punctuality and reliability, the need for efficient disturbance management solutions becomes evident. This thesis focuses on solutions that aim to minimise the consequences of disturbances for the various stakeholders and specifically on methods for re-scheduling the traffic. Railway traffic re-scheduling is a complex task with many influencing factors to consider and multiple stakeholders with sometimes conflicting interests. This problem is typically handled manually by traffic dispatchers that have a very limited access to support systems to facilitate their decision-making. This limitation hampers the possibilities to achieve sustainable and system-optimal decision-making and to provide the stakeholders with reliable traffic prognoses. We first study how railway traffic system users experience and are affected by the way the disturbances are communicated and handled by the traffic dispatchers. The results indicate that the disturbance-related information provided by the dispatchers is currently insufficient. The stakeholders need to acquire improved prognoses of their traffic and immediate part of the network to internally be able to minimise the negative effects of the distur- bances. Furthermore, an analysis of the disturbance management problem structure and how the problem can be modelled is provided. The analysis shows that there exist fundamental restrictions in the traffic system that bounds the traffic flow but also a large number of context-dependent con- siderations such as sustaining certain connections or prioritising specific trains. The prevalence and feasibility of such considerations are difficult to identify and model. Moreover, the objectives of the disturbance manage- ment are vague and partly unclear, and therefore it is also difficult to measure and evaluate the outcome of the corresponding decision-making. Finally, a number of optimisation-based solution approaches with the pur- pose to facilitate for the dispatchers and their decision-making has been developed. The performance and applicability of the approaches have been evaluated for various disturbance settings using data for parts of the Swed- ish railway network that currently experience capacity deficiencies. The evaluation has identified certain disturbances characteristics that have a significant influence on the disturbance propagation, and which in some cases complicate the re-scheduling procedure. Furthermore, the signifi- cance of applying certain re-scheduling objectives and their correlation with performance measures has been analysed. The analysis shows e.g. that a minimisation of accumulated delays has a tendency to delay more trains than a minimisation of total final delay or total delay costs. An experimental study of the long-term effects when applying a limited planning perspective has also been conducted. The results indicate that solutions which are good on longer-term can be achieved despite the use of a limited planning i horizon. In parallel to the optimisation-based approaches, an agent-based conceptual model with emphasis on the interplay between the different components in the railway traffic system has been proposed. Keywords: Railway traffic, Transportation, Re-scheduling, Disturbance management, Decision support systems. ii Acknowledgements I enrolled as a Ph. D. student at Blekinge Institute of Technology in August, 2001 and much thanks to my three supervisors, my past five years have been inspiring, motivating and challenging. Professor Paul Davidsson has been my primary supervisor, and independent of work load or matter he has all along given me the time and support I have needed, which I appre- ciate immensely. I am also very grateful to Dr. Jan Persson whom has been very inspiring to work with. The expertise and support provided by Profes- sor Peter Värbrand have also been important and his positive attitude has continuously kept me motivated. I am also grateful to the members of my research group DISL and my col- leagues at Campus Karlshamn and in Ronneby for providing a warm, fun and stimulating work environment. Especially, I want to thank Linda Ramstedt, Larry Henesey, Johan Holmgren, Ingrid Palmér and Anita Carls- son whom have enlightened my time at Campus Karlshamn. The municipality of Karlshamn, Banverket and Blekinge Institute of Tech- nology have financed my research and for that I am very thankful. I also want to thank BMT Transport Solutions and my colleagues there for giving me the opportunity to participate in some research projects and for provid- ing a nice work environment during my stay in Hamburg. Finally, I want to express my gratitude to my family and friends for persis- tent support and patience over the years. My good friends Anna Lindh, Inger Gustafsson, and Mats Lindqvist have been supportive in many ways which have meant a lot. My parents, Anders and Kerstin, and my sister Lottis have persistently motivated me and always been there to lean on – thank you!!! And André – thank you for always being so understanding, supportive and inspiring to be with. iii iv Preface This thesis summarises the research that I have conducted during my time as a Ph D student at Blekinge Institute of Technology (BTH) from