Optimal convoy composition for virtual coupling trains at junctions: A coalition formation game approach

•A mesoscopic convoy composition framework based on Coalition Formation Game approach to fill the gap of virtual coupling trains formation scheduling strategy considering transportation requirements and system limitations.•Defining and formalizing the dynamic coupling process of trains at junctions.•A novel train convoy formation algorithm converges to the composition structures of maximum efficiency improvements.•Estimating and validating for the applicability, the capacity benefit increases by 30.7 % in regional railways compared with the uncoupled mode, and it is not recommended to set a virtual coupling convoy over four units.