Could it be that the types of soils are penalizing or not in displacements? Example: speed 100% on road, 85% on grass, 50% on sand and marshes? History that the world is "felt" and that the roads are an interest other than aesthetic.
I think the idea is very good!
This could also be a parameter of footwear.
Some shoes are more suitable for some terrains than others.
However, the influence should not be too strong, so that players are not constantly forced to change their boots.