The line had been planned to quickly connect the main railway station with the newly planned E42 area in the southern suburbs, where the 1942 World Fair was supposed to be held.
Det var planlagt, at linjen hurtigt skulle forbinde hovedbanegården Termini med det nyligt planlagte E42-område i de sydlige forstæder, hvor Verdensudstillingen i 1942 skulle afholdes.