Its dependent not on BMW but the data that the system receives I seem to recall. So its possible that RDS/TMC in the UK doesn't supply that information, but abroad it might.
I've never quite worked out how to best use that section of the navigation, it seems to provide far too much information about roads you're nowhere near. I'll have to study it at some point.
I suspect the newer iDrive systems with RTTI are a bit more helpful still.