Delay management and energy consumption minimisation on a single-track railway

To become more competitive, railways are developing methods and technologies that enable cost reduction, higher capacity, better punctuality and greater sustainability. The authors of this study address the last two objectives and propose a method that can be used to minimise the impact of a single delay on the system by reducing both the deviation from timetabled arrival at timing points and the energy consumed by trains. The technique uses a combined macro- and microscopic level approach in an optimisation algorithm to calculate the maximum speed a train should travel at on different sections of its route, so that the train meets time constraints and saves energy. The algorithm interacts with the traffic management system to obtain the applicable time constraints. The initial results from a case study based on a single-track railway line show that applying this method to a freight train that needs to pass a late running passenger train at a loop and to arrive on time at its last station allows a 9% reduction in energy use by comparison with a situation where the freight train trajectory is not adjusted as a function of the actual traffic conditions.