It depends a lot. My hometown (at least the one in which I chose to live...), a rather large city near Hannover, is almost completely staffed with separate biking lanes. We even have a few in our historical downtown area, not too many though - probably because of preservation laws.

My parents live in a rural area near the state borders of Lower Saxony, close to the Harz. It is absolutely awful there - the next village (where the closest train station is) can only be reached over a ringroad with a "recommended speed" of 100 km/h. I guess I won't drive that part by bike, ever.