roads might be static sadly as I don't really know what happens to depending building if the modifier is removed.
the importance of the road is made in this case by the use you of it : the more you develop buildings the more cash you earn. but it fails simulating competition between roads or cities on 2 different roads.
trade nodes cumulate the bonuses of the different modifiers + cumulate the building possiblities. you might also make cross requirements for buildings, making some requiring both a land and fluvial modifier.
Can I use triggers like this?
Code:
any_neighbor_province = {
any_neighbor_province = {
limit = { Not = ROOT/THIS }
has_province_modifier = X
}
}
If it is possible, we can make a trade hub in a region, and a secondary area around it etc. and finaly a circle with a center of trade.
I'm working on a quite perveted system but it requires to disable completly boats from the map. then I changed the sprite for trade posts, made coastal (with a one dot maritime province in + adjacencies to link those) all provinces I want to be able to develop the trade post holding, then specialisation of holding with the modifiers+buildings system I described above.
http://i789.photobucket.com/albums/yy174/ArKoG/metz3_zpsb42aca33.png
Looks nice! Though I would have another idea about land provinces, since I hope there will be another way for cities than all you have to do is moving toward seas. F.e. South German cities had surely some connection with Holland or Venice, but their wealth was mainly based on products in Germany, Bohemia and Hungary.