In order to improve the state of knowledge of fare-free public transport, the Observatory carries out a precise census of the French areas where public transport is free.

What is a "selective free of charge for young people" network? It is a network in which users of a variable age group between 6 and 26 years of age have free-of-charge access to regular public transport services every day, on the perimeter of a municipality, an intercommunality, or the areas covered by the organizing authority of mobility.