the line saw its largest renovation on its western section in 1937 and impacted several lines. at the time, the route of line 10 did not respond to the needs of a large number of passengers, however the development of a section between "la motte-picquet" and "balard" had already been agreed upon, so the creation of line 14, "porte de vanves – bienvenüe" (today a part of line 13), stayed in the plans. these considerations led the "conseil municipal de paris" (municipal council of paris) to decide to have multiple extensions added and to effect a partial restructuring of the lines.