Omission and inference, these are features of language that everybody uses all the time. Language relies on common knowledge for omissions and inference to be understood. If everything needed to be stated all the time, communication would become excessively burdensome. Instead, most of the focus goes on to what needs to be said.
The last sentence of p. 19 is necessary for without it, combat on a road would be dictated by the road. If movement is also dictated by the terrain at a road's edges, this would also need to be said, so would also be in the sentence. The omission means movement is determined by the road. Everyone has a common knowledge of roads as something easy to move along, so in the context of the rules, roads must be good going.
Furthermore, it is not necessary to know what is under the road if an element is crossing the road. The going on the edges of the road is the same whether an element is astride or crossing the road, so if an element is caught crossing a road, the combat is as in the going of the road's edges because that is the rule.
If that is not enough, road fords (p. 20) are good going. Two points on this: first, if an element gets hit by a boat crossing a river, it is the river (not the road) that determines the going for the combat as just explained. And second, if moving through water on a road can be good going, I am sure a hard dry road is also good going, especially if it is paved.
Anthony
