This is an interesting thread, and I think I have not said anything here yet. Probably because I usually don't dream of specific roads, but rather sightseeing and when I put the travel plan together, I then look if there are any roads that I would be pulled towards.
This said, I had dreams of riding Trollstigen and Atlantic highway, in Norway. I did both of them in 2017, I believe. The latter of the two gave less of an expected emotion.
A while back I also had a dream to ride in Monument valley in sunset. However while planning the trip across the pond, I saw way too many obstacles with the visa requirements, that were really invasive to my privacy, so I have crossed USA off from my lists for the next few decades.