|Ruts between the stepping stones in Pompeii|
Which answer is true? Probably some combination of the two. The problem is that I can't seem to find a definitive source for any of the claims. I would appreciate anyone who can point me in the right direction on this issue.
Something else to consider is that the ruts can be found elsewhere in the roads than between the stepping stones. I believe that they are intentional and that they helped to guide the carts and wagons along the road without incident. While the ruts, or let's call them "tracks" (like a railroad), are useful for wheeled traffic, they do make the road more difficult and dangerous for the humans and animals which pulled/pushed these carts and wagons.