The purpose of SP3 of the Capacity 4 Rail project is to increase capacity by better methods for timetable planning and operational traffic and to analyse and evaluate capacity of infrastructure and new traffic systems. We have identified four planning horizons, which are strategic level (building of infrastructure), tactical level (timetabling), operational level (short-term rescheduling and dispatching) and driver advisory system (real-time). This deliverable analyse the existing methods for the tactical and operational levels from the aspect of their application for the enhancement of capacity utilisation. Improved methods in analytic, simulation and optimisation models for operational traffic control will raise either capacity utilisation (number of trains) or the punctuality. Operational control of railway traffic is recognised as the critical point in railway systems that requires an improvement. The application of novel computer-based decision support systems is recognised as a potential approach. The discrepancy between the current state of the existing tools for real-time traffic control and the practical operational requirements is identified as the main gap. The focus of the future work will therefore be in overcoming the obstacles that are preventing a straightforward application of the laboratory tools in a real-world environment. A set of potential scenarios that are required to validate the approaches is presented. The scenarios comprise the potential environments where the enhanced models could be applied. Different perspectives for defining the scenarios are considered. The scope and size, traffic heterogeneity, signalling system, the current level of traffic control and the availability of data are recognised as the crucial criteria for defining the scenarios. Finally, the Swedish southern mainline is recognised as the potential scenario that could be an appropriate instance for validation and evaluation of the models. Next steps are: Task 3.2.4 Enhancing frameworks for simulations and modelling and Task 3.2.5 Initial evaluation of scenarios.