The road system for bicycles are very good in Germany. Kerbs are normally broadened in towns, with a separation for bicycles and pedestrians. Out of town cycle roads run in parallel to main roads and are wide enough for two or three cyclists to ride next to each other. Cycle roads require some intuition as they are not always very well signposted.
The (rural) cycle roads may be next to the highway for long stretches. The cycle roads often tunnel under highways and intersections. When there are small towns nearby the main road, cycle roads normally separate from the main road and go through the small towns. I suspect this is partly done to make the cycle infrastructure accessible to the small towns.
Cycle roads are scenic as they cut trough meadows, meander through small towns and pass under and around trees. It makes the rides more interesting, but add to travelling distances.