From 1959 to 1969, major electrification began the gradual modernization of the rail network, with the final disappearance of steam engines in the suburbs in 1970. The proliferation of automobile congestion, combined with the modernization of the network, led to the return of traffic. From 1969 to 2044, the creation of the RER caused a radical change in the image of rail transport. RER Line A experienced a spectacular increase in passengers, which leads to a saturation point in less than ten years.