I agree that the situation is not easy. However currently it looks like the cars are only driving next to the tram for a short portion of the street while actually they can drive the whole time next to the tram except on the tram stop "Trachau". The street is just usually full of parked cars so they have to drive at the tram way. I wouldn't add this extra lane, it just makes things complicated. After all the street already denotes this with the tag "lanes = 3" also the number of lanes is reduced near the tram stop. So in my eyes everything was correct here.