… Pompeii had one-way streets, and a pedestrian zone around the forum? This and much more you can discover in Mary Beard's new book, The Fires of Vesuvius: Pompeii Lost and Found.
A similar photo to the one below, courtesy of Wikimedia Commons, is one of the many illustrations in the book. Streets were constructed with raised sidewalks and stepping stones to handle over-flow water. Space between the stepping stones allowed carts to go through. In the distance one can see a water tower.
Wikimedia Commons has quite a few images of ancient Pompeii, which can be found here, organized by subject.