Alan McG
Cannelloni
It depends currently only on the size of the city and is given by (1 + 1.25 * citysize). The size of the capital city doesn't matter (although it can be modded very easily so it does)
You only get one trade route. Having both a harbor and road connection would only provide redundancy. For example, if an enemy unit is in the vicinity of the harbor city and blocking its route, then the road route would come in effect.
There can still be reason to use more than one harbor on the same continent. It shouldn't be hard to come up with possible scenarios of that if you consider that roads cost 1per tile per turn, and a harbor only 3
per turn, and long distances / impassable terrain.
Also harbor to harbor connections count as railroad connections once it's discovered, making it possible to save even more gold because railroads are more expensive to maintain. And I haven't mentioned yet the bonus to ship building, which could be relevant in some cities.
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!