The way the Métro started its life strongly influenced signage in the stations. In the early days, a number of commercial companies ran the different Métro lines. This is one of the reasons why the inscriptions varied enormously, from enamel signage to big ceramic station nameplates. Sans serifs were mostly used for big signage, and on the carriages, letters were painted in a style appropriate to the carriage design. Early on, it was Art Nouveau forms. At the time, most of the transportation procedure was done manually by rail workers, from the sale of individual tickets, to the semi-automatic door closing. Later, the national rail network, the RATP, took over.
From Métro Type, a history of type and signage in the Paris Metro system.