The situation is fairly interesting: In the old eastern part streetcars still exist, while they were dismantled in the old western parts. I notice that the streetcar fills an important role in the transport network: It's faster, more reliable and higher capacity than buses but still cheaper and with a more dense network than subway or light rail. It efficiently bridges the gap and provides access to to areas that are less well connected by the large lines. Reaching those areas in East Berlin is a breeze, reaching them in West Berlin a pain. Street cars usually don't share the roads though.