hello! The sign with a W shows the pronounciation in German, the other one is for Eastern Europe. None of them is for English-speaking people. Haha.
 Didnt u know that in Bulgaria the transcription depends on the political situation?
 Like those signs here: the older one is from the time we were close with the German culture. And so on...
 Today we r trying to impress the Anglos, so we make the transcription "suitable" for them... 20 years ago, it was for the Frenchies (my first passport was in French)..
 I hope u got it :)