WAS MACHST DU DENN DA?
The Vienna S-Bahn is not a separate rail network. It is integrated with, and part of, the national railway system. As such, S-Bahn trains share tracks with regional trains (which travel further than the S-Bahn, some regional lines crossing into neighboring countries) and other rail traffic, including freight trains.
Slovakian writers are connecting Vienna S-Bahn, regional trains and Vienna U-Bahn with something what is called graffiti. How they are doin’ it you can see on this photos and a very nice video on the bottom of this page. Enjoy a colorfull evening.