The issue of roads through stone circles has been around a long time. The A4361 (Swindon to Devizes) road snakes through the Avebury Stone Circle and there is no possibility of it ever being moved as there is nowhere else to put it without causing untold damage.
I imagine the same is true of the Rollrights - I have visited a few times courtesy friends with cars, the road always seemed comparatively quiet. To close it and build another one would destroy other landscapes, albeit no stone circles on them. I don't own a car but recognise roads are essential for transporting ourselves around. I feel quite strongly that there are enough roads and, so long as they are kept in good repair, we don't need anymore.
Thanks for reminding me about the Hoar Stone, I loved it when I visited.