I’m kind of in the same boat. A couple of years ago I did a 700k tour on virtually only minor roads (I believe about 10k was on roads with a center line). I use

I’m kind of in the same boat. A couple of years ago I did a 700k tour on virtually only minor roads (I believe about 10k was on roads with a center line). I used cycle.travel[1]. I’m in Europe, not sure how good it is elsewhere, but here it is incomprehensibly better than Google for this purpose. [1] https://cycle.travel/map https://cycle.travel/map