Simulation der Fahrplanerstellung auf der Basis eines hierarchischen Trassenmanagements und Nachweis der Stabilität der Betriebsabwicklung

This paper focuses on the further development of the asynchronous method to simulate timetable compilation and railway operation. The newly developed simulation strategy and the use of appropriate basic components introduced in the field of timetable compilation lead to a train priorities respecting simulation procedure that can be used for various stages of the railway planning process. The use of existing basic components enables the procedure to employ infrastructure and timetable data from all over the German network already available. The new asynchronous simulation procedure provides improved solutions for classic questions of railway operation science, such as the calculation of infrastructure capacity or the validation of new timetables and operational concepts. It delivers better results because conflicts between train movements are resolved in a more sophisticated way, particularly on single track lines and in complex networks. This is achieved through automatic choice of alternative train-paths, section-wise resolution of conflicts, and the adaptive calculation of different conflict resolution alternatives where the choice is made with the help of target functions. The paper contains an overview on existing railway operation science models and on timetable compilation methods. The algorithmic complexity of automatic timetable compilation is discussed and corresponding mathematical approaches are analysed. It is demonstrated that, due to the combinatorial variety of possible train sequences and train-path alternatives, mathematical approaches require simplified mathematical modelling structures. However, these simplified modelling structures do not contrib-ute to solve the everyday problems of timetable compilation. Whereas the new procedure is based on concepts similar to the basic ideas of the existing support tool for timetable compilation - namely the idea of occupation times for block sections and the specific consideration of conflicts between train movements - and enables new applications in this area by introducing improved strategies of conflict resolution. As a result, the efficiency of IT supported timetable compilation can be improved as the new method creates various conflict resolution alternatives, searches the existing timetable for free train-paths and inserts additional train paths by using remaining infrastructure capacity in an economical manner. The operation simulation procedure embodied in the new technique makes it possible to check the stability of any timetable and thus to provide early quality assurance of timetable planning processes