The new century seen remarkable changes in the management of urban transport: in January 1906 it was prepared the new Convention for the management of the municipal network service between the City of Florence and the “Company of the Florentines tramcar for the exercise of new lines “(an international company known as the” Belgian “), together the City of Florence established to replace the omnibus lines with tram lines and, under the pressure of increasing social demands, reduced tickets were issued for the workers.
Meanwhile the Italian automotive industry was growing and would soon become protagonist of public transport: in 1913 it was set up on an experimental basis a bus service between Piazza Vittorio Emanuele and Viale Petrarca. At the end of the First World War it was born the SITA (Italian Society of Automobile Transport), a branch of Fiat, which the town will turn finally putting in crisis the “Belgian Society”.
1935 Municipality and Fiat are jointly the STU (Urban Tram Service) which takes all the concessions of the Florence transportation lines. The new company continues the strengthening and expansion of communication lines up to stall during the years of World War II.