Glad to see this continuing
As far as the city scale goes, it would depend on the style of the map. If you are going full-to-scale and no abstracts, I would have to say "yes". However, I would say that a LITTLE exageration for the sake of clarity should be allowed. The problem with exageratiing the roads themselves is that they will have a tendancy to throw off the scale of the buildings as those that face the road will have one dimention shortened...City walls can always be exagerated outwards and have a very minimal effect on the rest of the city, bridges a little less so, but doable with care, but I wouldn't do the roads. In a true full-to-scale map.