No stop & go traffic
Well, you got to know that black forest is THE place for people who want to enjoy their motorbike or car. There are normal people that just drive through this area, there are tourist that drive with 50kph and try to enjoy the view (GO HOME!!
) and there are sportcar drivers and mostly motorbike drivers that are on a fast run.
You'll meet bike drivers that drive like on a race track with their machines. It's crazy and that is what EmmDrei ment.
I did several thousands KM in the black forest but never had any problems. You got to stay concentrated and watch out for other cars. There are wider roads and there are tiny and small ones. It differs very much.
Just searched for some videos and that's what I would could a small to narrow road in black forest (it has no road marking in the middle):