Help with parameter data

[phoenix]

I'm a bit confused about what the movement costs mean in the parameter data dialogue. I'm trying to find out which terrain types/hex edges are impassable. So, in the pic below, for example, the cost for infantry for moving on a road, in line, is given as 0, but also for moving over a creek, or water. Is there some other part of the PD dialogue that shows what terrain is impassable, that I am missing? I assume water, at least, is impassable, but road is not. Infantry can move in line along a road, I assume, though they will risk disorder. In column it costs them 1 to move along a road, but 0 to move over water? I don't get it. Is it that things like water have no costs attached because you can't move there at all? And if so, as I said, where do I find the list of hex sides or hex terrain types that are impassable?

Thanks.

Peter