Who benefits most from fare-free public transport? Evidence of social and neighborhood effects from the case of Clermont-Ferrand, France

This paper estimates the impact on household mobility of the fare-free public transport measure implemented on weekends in Clermont-Ferrand, France. More precisely, we are interested in the influence of socioeconomic determinants on the likelihood of using public transport more often following the introduction of a free travel measure. We investigate changes in travel behavior at the individual level, using data from the household travel survey (Cerema Certified Mobility Survey -EMC²) conducted in the metropolitan area of Clermont-Ferrand in 2023. We built a weighted binary logistic regression to estimate the probability that users increase their public transport use due to the fare-free policy, depending on their socioeconomic characteristics. The results show that free public transport increased usage for more than half of users, with effects varying across individual characteristics. In Clermont-Ferrand, low-income households, residents of priority urban districts, and families with children benefit more from the fare-free policy. We demonstrate that residing in a priority urban district (QPV) has a specific impact. All else being equal, residents living in a QPV have an estimated 85% probability of increasing their use of public transport following the introduction of farefree travel, corresponding to a 31-percentage-point (pp) higher probability than residents living outside a QPV. Therefore, the estimated impacts are not merely compositional but reflect genuine contextual externalities operating at the local level: There exists a neighborhood effect. This study intends to contribute to the literature on free public transport policy evaluation, with a focus on the socioeconomic heterogeneity of effects.