Bienvenüe's project consisted of 10 lines, which correspond to current Line 1 to 9. Construction was so intense that by 1920, despite a few changes from schedule, most lines had been completed. The shield method of construction was rejected in favor of the cut-and-cover method in order to speed up work. Bienvenüe, a highly regarded engineer, designed a special procedure of building the tunnels to allow the swift repaving of roads, and is credited with a largely swift and relatively uneventful construction through the difficult and heterogeneous soils and rocks.