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Designing a short term line planning model

Kamphorst, MSc M.G.B. (2015) Designing a short term line planning model.

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Abstract:This research is conducted at NS (the main railway operator in the Netherlands) in the field of line planning. In line planning, strategic decisions are made concerning which set of line routes to use together with their frequency (called a line plan) for rolling stock equipment. A line route indicates where rolling stocks starts, on which track sections rolling stock drives, which stations the rolling stock visits, and where rolling stock eventually stops. NS tries to fit their line plan as efficient as possible to travel patterns of travelers. Since travel patterns of travelers change over time, NS has to adapt their line plan on these changes. NS has developed a Line Planning Model to support the line planning process. This model is developed to generate an ideal line plan for over 20-30 years. Using the railway infrastructure and the traveler demands, the Line Planning Model creates this ideal line plan. This research is performed to make the Line Planning Model capable of generating line plans for 0-5 years in ahead. Since the current practice of NS is quite dependent on the line plan, NS is not able to make a lot of changes in 0-5 years in their current line plan. Therefore, the short term Line Planning Model, developed in the research, must be able to suggest small changes in the current line plan of NS. The focus of this research is to define small line plan changes, construct restrictions for a short term line plan, and implement an Algorithmic Search Procedure (ASP) that is able to perform these small changes to create a short term line plan. For the short term Line Planning Model, four different small changes of a line plan are defined: route changes, head-tail changes, merging or splitting, and changes of connections. In route changes, a small part of the route of a line route is changed in which the start and end station stays the same. Head-tail changes consist of enlarging or shortening the ends of a line route. Merging merges two line routes into one line route and splitting splits a line route into two separate line routes. Finally, changes of connections consist of changing connections of two line routes at a certain station where both line routes pass by. The second objective of this research is to develop restrictions for short term line plans. The first restriction is a rolling stock restriction, in which the short term line plan may not use more rolling stock than the current line plan of NS. A serving restriction is set to ensure that every station on the Dutch railway network is served. Further, a turbulence restriction is developed to ensure that for most travelers the travel time does not increase. Finally, most line routes of the short term line plan must be exactly the same according to the current line plan of NS and on most track sections the short term line plan may not drive less frequently. The last element of the short term line planning model is the development of an Algorithmic Search Procedure that is able to suggest the small changes in the current line plan of NS and is able to handle the restrictions. During an experimental and a practical evaluation, we concluded that Steepest Descent is most suitable to implement in the short term Line Planning Model. Steepest Descent evaluates all possible small changes of a line plan and selects the change with the highest improvement. The search procedure continues until no improvements are found in the line plan of NS within the restrictions for short term line plans. In this research, the short term Line Planning Model is executed on a real life example. The real life example consists of finding improvements in the off-peak line plan of 2019. The short term Line Planning Model is capable of finding a revenue increase of 18,268. In 9 changes these improvements are realized.
Item Type:Essay (Master)
Faculty:BMS: Behavioural, Management and Social Sciences
Subject:55 traffic technology, transport technology
Programme:Industrial Engineering and Management MSc (60029)
Link to this item:http://purl.utwente.nl/essays/67961
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