A Digital-Twin approach to improve the performance of single-track rail lines

Rail transport is crucial for sustainable mobility, but in low-density regions, it often relies on single-track and diesel-powered lines. This infrastructural constraint limits operational efficiency, as trains travelling in opposite directions must use designated meeting points, usually at stations, reducing service attractiveness. Hence, single-track railways face significant challenges in performance and investment feasibility. Indeed, high costs and low passenger demand make infrastructure upgrades, such as track doubling, difficult to justify. Moreover, diesel traction contradicts sustainability objectives, necessitating greener alternatives such as electrification, hydrogen or hybrid trains. This paper presents a Digital Twin-based methodology to analyse and optimise single-track railway lines. The proposed model identifies bottlenecks and inefficiencies, allowing for the assessment of technological and operational improvements. By integrating real-world data and advanced simulation capabilities, the Digital Twin framework serves as a decision-support tool for railway planners, aiding in infrastructure investments, scheduling optimization, and the transition to sustainable propulsion systems. A case study on a regional railway in southern Italy demonstrates the potential of this approach, showing how the Digital Twin model can enhance service reliability and attractiveness.