Rolling stock management and railway efficiency: Evidence from a line-level analysis of regional rail services in France

Previous railway efficiency studies largely rely on aggregated data, which limits insight into the operational drivers of performance. Using a unique line-level dataset from a French region (117 observations), this paper leverages fine-grained information to explain within-region heterogeneity by linking cost efficiency to rolling-stock characteristics and maintenance practices. Results identify rolling stock as a central efficiency determinant. Lines operated with older, heterogeneous fleets are systematically less efficient, consistent with higher maintenance complexity and weaker standardization. Operating density also remains a key correlate, confirming economies of density. These findings are critical for the transition to competitive tendering. As networks fragment into bundles, line-level benchmarking aligns with procurement. The proposed framework distinguishes non-discretionary constraints from discretionary levers under the PTA's and operator's responsibility. Ultimately, these metrics provide a quantitative foundation for contract negotiation and investment planning, facilitating the arbitration between operational efficiency gains and the capital costs of fleet transformation.