For the most part what are being described are my favorite roads -- generally winding with low traffic and to places that have few people.
Worst roads would be crowded Interstates that are referred to as Beltways around East or West Coast Cities or a two lane bridge that is Bumper to Bumper and only 20 feet wide going to Long Island.
Those tight switchbacks in the Rockies just bring a smile to my face, as they generally lead to the best sights of the day. IMHO the road is not the issue it's the number of other DRIVERS that will make a road un-enjoyable.
JMHO,