Similar systems already exist in and around other capitals such as the RER in and around Paris and the S-Bahn in Berlin.
The idea is to offer commuters and those travelling in and out of time for leisure pursuits a valid alternative to the car. The more people that take the train, the shorter the traffic jams will be is the philosophy.
The current "S-network" of suburban train services falls well short of what the GEN network will be. Work on the Regional Express Network should have been completed in 2012. However, a string of delay have meant that the official launch has been put back to 2025. In the meantime the Belgian rail company NMBS has been gradually increasing the number of S-network services.
In March work will recommence on line 161 that runs between Brussels and Namur. The section between Brussels and Ottignies is being upgraded to from 2 to 4 tracks. Work to upgrade the section between Watermaal-Bosvoorde (Brussels) and Hoeilaart (Flemish Brabant) will start in two months’ time.