Comment by sandmn

In Vienna they don't have gates at all or even much indication where gates supposed to be. My first visit I accidentally didn't pay for my ticket - I'm used to ticket machines being near the gates but I couldn't spot any. I also arrived on a train so I thought that since there was no gates or visible ticket machines between train and subway, maybe my train ticket is valid for a subway trip (happens in some places) but it was not the case.