Knowing the load of a transport system is one of the critical information of the operators and allows them to take strategic moves to optimize the line, involving more buses or changing the missions of the buses. Having this information in real-time and in the near future opens a new dimension in the management possibilities of the line. The paper describes a prototype that demonstrates this possibility and exposes the methodology used and some examples of the results. The study here presented was possible thanks to a new kind of data: the counting of passengers boarding and dropping out at each stop provide by sensors installed above the doors.