I’m pretty sure I’ve be not noticed any speed difference traveling on wilderness map.
Hills in Finland tend to be very mellow, I’d say they’re faster to travel on foot than open or pine mire.
Groves, Heath, lichenous, hills would all be fast to travel.. Spruce mire can be dense, or but more sparse, getting through dense is slow, getting through more sparse and it’s as easy as heath. Thickets are slow to get through.
That said, edges of heath sand ridges are absolute pain to climb. Especially when hauling crates of landmines.