A New Hierarchical Approach for Optimized Train Path Assignment with Traffic Days

Abstract

German Railways Infrastructure division DB Netz has started to gradually introduce a new process for its rail freight timetabling. This process contains two main stages: at first a pre-planning of standardized train paths (called slots) and afterwards the assignment of train path applications to the pre-planned slots. The current implemented train path assignment optimization model by Nachtigall and Opitz 2014 has a model scope of one single traffic day. However, current train path applications for the network timetable have multiple and diverse traffic days (e.g. Monday till Friday or Tuesday and Thursday) and cannot be assigned appropriately today. At first it will be illustrated by what a good train path assignment with multiple traffic days is characterized from the point of view of an infrastructure manager and its customers. Subsequently, a new hierarchical approach for train path assignment with different traffic days will be presented which is derived from the analysis of present train path applications. The analyses of a German long term timetable scenario indicate that this new approach generates promising results.