Efficient preparation and smooth operation of rail freight trains are essential for improving rail freight services and customer satisfaction. This study examines how automation and digitalisation − specifically Digital Automatic Coupling (DAC) and Virtual Coupling (VC) − can enable seamless rail freight transport within marshalling yards and along railway lines. For the first time, a combined simulation- and optimisation-based modelling approach is proposed to assess the impact of these technologies.A multi-agent simulation model of the Hallsberg marshalling yard was developed to analyse train handling and yard capacity. A 10-hour shunting operation was simulated under manual coupling and DAC technology, comparing standard train lengths and longer trains. The results indicate a substantial increase in processed trains when DAC was applied. Standard-length trains increased from 7 (manual) to 9 and 12 with DAC types 4 and 5, respectively, with similar gains observed for longer trains.Trains from the simulation’s departure yard were subsequently integrated into an optimisation model to assess their scheduling on the main railway line. dispatchers face challenges in optimising freight train routing, VC was proposed as a capacity-enhancing measure. The optimisation results showed that, with conventional timetables, only 70 freight trains could be scheduled while prioritising passenger services, whereas VC enables up to 128 freight trains − − an 82.86% capacity increase.Overall, these results demonstrate that integrating DAC and VC technologies can significantly enhance the efficiency and capacity of rail freight operations and systems, offering substantial benefits to stakeholders across the sector.