With the Roads of the Rim Mod caravans can create road construction sites to build roads between two neighboring tiles on the world map. By using the “Work” action, caravans provide work and resources to the site until completion.
Building costs are based on the type of road to be built & the terrain of both tiles. Roads cost wood, stones, steel & chemfuel. If deemed too high, base costs can be reduced in the mod settings (but that’d definitely be OP).
The Roads of the Rim Mod changes the movement multipliers for existing roads as indicated in the “Terrain” tab under Movement difficulty. This can be switched off in the mod settings as well.