I have ridden my CB1100 EX on a sandy road that got continually worse as I went. A white knuckle experience as it always slipped sideways down hills.
My other experience was exploring the Kennelly Mountain Road that quickly turned to a gravel road. Then narrowed to a gravel lane. Then a rocky trail. The only oncoming traffic I encountered was a large pick-up truck. Luckily we met at the only place on the trail that was wide enough for us to pass. The trail ended up as a very narrow sandy road. When I came to a unmarked fork in the road, I had no idea which way to go. So I decided to take the one that had the most tire tracks. Fortunately it was the right choice and I ended up at the Ferguson Lake Road which I was familiar with.