Efficiency Evaluation in the Regional Railway Sector: Evidence from a Shift to Line-Level Analysis

As competition enters the French regional railway sector, assessing how public service operators achieve efficiency has become both a regulatory and strategic priority. Traditional evaluations, often conducted at national or regional levels, tend to overlook the diversity of operating conditions within regions. This paper introduces a novel analytical scale for efficiency evaluation, the line level, which enables genuinely like-for-like comparisons across services that share similar operational characteristics. This is possible due to the existence of accountability to a line-level. Using a unique dataset covering 147 French regional lines between 2015 and 2019, we apply Stochastic Frontier Analysis (SFA) to measure operational efficiency based on cost drivers such as rolling stock, staff, and energy. The results reveal substantial heterogeneity both across and within regions, demonstrating that aggregated indicators conceal meaningful local variations. Beyond its empirical findings, this paper proposes a replicable and policy-oriented framework for evidence-based evaluation at the operational scale, supporting ex-ante, in-itinere, and ex-post assessments of regional rail performance in a liberalised environment.