Demand-oriented integration optimization of train timetabling and rolling stock circulation planning with flexible train compositions: A column-generation-based approach

•A train timetable and rolling stock circulation plan were simultaneously optimized.•The model considers flexible train compositions on an urban rail line.•An integer linear programming model based on a column-generation algorithm is shown.•The model was verified using real-world data from the Shanghai Metro.•The model optimizes the trade off between passenger demand and cost effectiveness.