Andrew: Solution for overland map movement limitations?

[LoBaron]

Andy, just an idea, but is it possible to prevent/reset "move" orders?

Areas which were extremely hard to pass could trigger "combat" mode, so the
speed advantage of move mode does not come into effect.

In general this could be applied to a certain number of terrain types, except when roads are present.
Could be implemented for mountain/hills/jungle.

If not otherwise possible you could simply simulate an exposure to air attack to get the desired effect
in above terrain types.