However, in a very wooded land, could you have seen the lowland route around contours? Could you navigate around a hill from in a forest? If you could see up to a high marker that you knew pointed to a safe pass through the hills wouldn't you take it?
If you were fit because you worked outside, walked everywhere anyway, and could climb a hill without needing to stop every 10 vertical metres for a fag (like I do) wouldn't it be easier to go up and over if you knew it to be safe rather than around?
I'm not in a position to say. I doubt many folk are today.
As a total aside, but related to all this in a way ... It's silly how some folk will accept one theory, i.e. Darwinian Evolution, and ignore the the gaps in Darwin's version of it, and then totally dismiss another theory because of a gap that could be relatively smaller than the Darwin-theory gap. It's all down to what you've been taught and told is fact I suppose.