Ok, thanks for that. IMO a harbour should have additional commerce benefits, the current benefit seems way too poor. Even if in theory they represent a better investment than roads as far as trade routes are concerned, you still need to have your cities within the same landmass linked by roads for quick unit movement. Additional questions: a) Building railroad on top of road: total of 2 gold maintenance (railroad cost) or 3 gold (road+railroad)? I ask because when building rail on top of roads workers do not ask for confirmation on 'replacing improvement', and you have the option to build a railroad right away without building a road first. b) Is there no way to tell a worker to 'build railroad to xx'? Do I have to manually tell him tile by tile? Cheers!