Big movement range only on roads?

[geala]

I don't like that roads only add a small additional movement range and that armies can move rather far through difficult terrain. The range on roads should be three to four times of that without roads. I would like to try to mod this (don't know how to do or wether there is already a mod like this but will see). But: do you think that a rather small movement through normal terrain and big army ranges only on roads would seriously hamper the AI?

[Dresden]

You can change the values in campaign_map_roads (I think it is). I have tried altering it so that they are better but there is some sort of hardcoded limit on how much you can change movement.

You can also alter the campaign_terrain table.