Given the scope for growth in rail demand in the greater Dublin area, the review envisages that Iarnród Éireann should be aiming at a "turn up and go" service on the Dublin suburban rail network. It also envisages that the four main rail corridors coming into the city of Dublin should give commuters the type of service that would make their travel more attractive, speedy and reliable. It is acknowledged that planning flexibility is required because of the need to respond to the demographic changes and housing development along the four rail corridors, which are the backbone of the suburban system, that is, the Kildare, Maynooth, north-eastern and south-eastern corridors.