Are punctual and regular train lines efficient? Re-evaluating regional railway performance with a service quality-integrated DEA framework

Are the most cost-efficient train lines providing the best service? This study demonstrates that efficiency models often misidentify operational success, rewarding lines with significant service quality deficits. Based on a granular analysis of 174 line-year observations across 58 French regional railway lines, we propose and apply a new efficiency framework. By incorporating essential Quality of Service indicators (punctuality, regularity, frequency and crowding) into the evaluation, we reveal a fundamental reshuffling of performance rankings. Our findings show a clear divergence: cost-efficient lines with poor service are penalized, while lines delivering high-quality service see their performance scores improve significantly. The analysis further identifies the distinct characteristics of lines that experience the greatest changes in rank. As France moves towards competitive tendering in the rail sector, these results carry significant policy implications. A sole focus on cost-efficiency risks incentivizing service degradation. This research offers Public Transport Authorities a robust, quality-aware tool to facilitate more accurate performance diagnostics, identify benchmark lines, and ultimately foster a system that prioritizes both economic viability and passenger welfare.