[GS] Canals, Railroads, and Trade Routes

[VCrakeV]

Does anyone know the relation between railroads and trade routes; and canals and trade routes? Do they affect domestic and international? What yields do they affect, and by how much?

 

[mrjepson]

I'm not sure on the exact numbers but trade routes that run along along railroads are worth way more.

 

[ggmoyang]

I found these lines in Expansion2_GlobalParameters.xml. Not sure about the exact formula, but it looks like a number for trade route bonus for tile feature(s).

<Replace Value="1.0" Name="TRADE_ROUTE_TRANSPORTATION_EFFICIENCY_MAX_RATIO"/>
<Replace Value="2" Name="TRADE_ROUTE_TRANSPORTATION_EFFICIENCY_SCORE_BEST_ROUTE_TILE"/>
<Replace Value="15" Name="TRADE_ROUTE_TRANSPORTATION_EFFICIENCY_SCORE_MULTIPLE_DOMAINS"/>
<Replace Value="15" Name="TRADE_ROUTE_TRANSPORTATION_EFFICIENCY_SCORE_PORTAL_USE"/>
<Replace Value="2" Name="TRADE_ROUTE_TRANSPORTATION_EFFICIENCY_SCORE_WATER_TILE"/>

 

[Brutus2]

I'd love to hear people's thoughts on how useful railroads really are. I already get crazy high gold from late game international trade routes without railroads, is the increase really worth the added CO2 and eventual expenses of damaged coastal tiles and increased weather damage? I have yet to build a single railroad tile in any of my games yet.

 

[Sostratus]

They seem to affect int'l routes only and only for gold.
Essentially there is a "TRANSPORTATION_EFFICIENCY" that is how much of the route is water or rail tiles. The more of the route is "efficient" the higher the gold bonus - up to 100% bonus gold.
However there's more to the story. The bonus for route efficiency is not 1:1 - you can get 100% bonus with much less than a pure water route.
I did some quick investigating off of a save:
6/21 tiles railroad = 0.285 > 51.95% bonus
6/15 tiles rail = 0.4 > 70-71% ish (i didn't write down enough digits... 70.something!)
7/14 tiles rail = 0.5 > 87.5% bonus
These 3 points actually make a perfect line. [slope 1.6535, intercept 0.04825]
The value for which you get the full 100% bonus is actually just 57.5% of the route [*EDIT: according to this line equation, I haven't verified but it's at least close to that.*] Go ahead and look at water routes that go a little inland- you'll see you don't need much to get the max.
This get a little more complex with canals. Canals appear to add 1 gold to the bonus per tile, based on a couple routes I had that went through my panama canal. So you can exceed the 100% cap with them. I didn't see any cap busting for foreign trade posts, but they could already be lumped into the figure. (You can hover over the route before you select it to get the breakdown, but gold bonuses from trade posts, canals, rails, and water are all lumped in the same number.) I'd have to play as trajan to see if your domestic Tpost bonuses get doubled or not; similar with spain's bonus and things like zimbabwe.

I'd love to hear people's thoughts on how useful railroads really are.

Rails let you travel twice as fast as roads (0.25 move) which is fantastic for your military mobility. The co2 usage is fairly negligible - right now using a unit of fuel is the same co2 no matter how its used, so building a 30 tile railroad is the same as burning 3 coal per turn for 10 turns in a coal plant. I find movement to be much more useful than trade especially if your routes go over water - see above- although if you have a land border it's very useful to build at least one or two railroad "spines" across your empire to funnel traders along.

The other thing is that late game, the Ai's standing militaries consume enough oil per turn that you'll get coastal flooding regardless. If they have it, AIs can burn plenty of coal too, but they WILL use oil units and there's nothing anyone can do about it.

 

[VCrakeV]

They seem to affect int'l routes only and only for gold.
Essentially there is a "TRANSPORTATION_EFFICIENCY" that is how much of the route is water or rail tiles. The more of the route is "efficient" the higher the gold bonus - up to 100% bonus gold.
However there's more to the story. The bonus for route efficiency is not 1:1 - you can get 100% bonus with much less than a pure water route.
I did some quick investigating off of a save:
6/21 tiles railroad = 0.285 > 51.95% bonus
6/15 tiles rail = 0.4 > 70-71% ish (i didn't write down enough digits... 70.something!)
7/14 tiles rail = 0.5 > 87.5% bonus
These 3 points actually make a perfect line. [slope 1.6535, intercept 0.04825]
The value for which you get the full 100% bonus is actually just 57.5% of the route. Go ahead and look at water routes that go a little inland- you'll see you don't need much to get the max.
This get a little more complex with canals. Canals appear to add 1 gold to the bonus per tile, based on a couple routes I had that went through my panama canal. So you can exceed the 100% cap with them. I didn't see any cap busting for foreign trade posts, but they could already be lumped into the figure. (You can hover over the route before you select it to get the breakdown, but gold bonuses from trade posts, canals, rails, and water are all lumped in the same number.) I'd have to play as trajan to see if your domestic Tpost bonuses get doubled or not; similar with spain's bonus and things like zimbabwe.


Rails let you travel twice as fast as roads (0.25 move) which is fantastic for your military mobility. The co2 usage is fairly negligible - right now using a unit of fuel is the same co2 no matter how its used, so building a 30 tile railroad is the same as burning 3 coal per turn for 10 turns in a coal plant. I find movement to be much more useful than trade especially if your routes go over water - see above- although if you have a land border it's very useful to build at least one or two railroad "spines" across your empire to funnel traders along.

The other thing is that late game, the Ai's standing militaries consume enough oil per turn that you'll get coastal flooding regardless. If they have it, AIs can burn plenty of coal too, but they WILL use oil units and there's nothing anyone can do about it.

Thanks for the info dump. I don't see Firaxis doesn't provide explicit details in the civilopedia. It's a shame these bonuses don't affect domestic routes; international routes are already better most of the time.

 

[ggmoyang]

The value for which you get the full 100% bonus is actually just 57.5% of the route [*EDIT: according to this line equation, I haven't verified but it's at least close to that.*]

Thanks for the research! 57.5% is such a weird number. Anyways, XML says

<Replace Value="2" Name="TRADE_ROUTE_TRANSPORTATION_EFFICIENCY_SCORE_BEST_ROUTE_TILE"/>

So is this means you need something like 115% transportation efficiency score? And maybe you only need 7.67% of canal/mountain tunnel to reach maximum transportation efficiency score?

 

[Sostratus]

It's a shame these bonuses don't affect domestic routes; international routes are already better most of the time.

I agree, there is a lost opportunity to do something with food and production yields and coastal cities (which is who needs this stuff!)
But now that you can combo international trade bonus cards, and wisselbanken + democracy, your alliance routes are so strong its almost moot.

 

[Sostratus]

So is this means you need something like 115% transportation efficiency score? And maybe you only need 7.67% of canal/mountain tunnel to reach maximum transportation efficiency score?

I'm not sure about mountain tunnels. I know canals just straight up add 1 gold for passing through them (canals also count as water tiles for efficiency.)
If I understand the XML correctly, what they do is give a value to each tile (2 for water, 2 for rail, 1 for everything else) and divide that sum by the route length. So a pure water route for N tiles would be 2*N score / N tiles =2.
So if that's true then we can express things like so
N total tiles
M water/rail tiles (counts for 2)

Efficiency Score = [2*M + 1* (N-M)] / N
If there's only water/rails and regular tiles then
Divide through N
= 2*(M/N) + 1*(N/N - M/N)
= 2(M/N) + 1 - M/N
= M/N +1.

The ratio M/N is the proportion of water/rail tiles to all tiles, exactly the % numbers I was using. However, the code seems to suggest that "portals" (mountain tunnels?) are worth 15 for going through! So this efficiency score equation is the bridge between those worlds. Tiles worth more than 3 would just reduce the overall amount of tiles better than one you would need to use to get to the 100% bonus, because it would be easier to hit that 1.5756 score you need.

 

[UWHabs]

I'm not sure about mountain tunnels. I know canals just straight up add 1 gold for passing through them (canals also count as water tiles for efficiency.)
If I understand the XML correctly, what they do is give a value to each tile (2 for water, 2 for rail, 1 for everything else) and divide that sum by the route length. So a pure water route for N tiles would be 2*N score / N tiles =2.
So if that's true then we can express things like so
N total tiles
M water/rail tiles (counts for 2)

Efficiency Score = [2*M + 1* (N-M)] / N
If there's only water/rails and regular tiles then
Divide through N
= 2*(M/N) + 1*(N/N - M/N)
= 2(M/N) + 1 - M/N
= M/N +1.

The ratio M/N is the proportion of water/rail tiles to all tiles, exactly the % numbers I was using. However, the code seems to suggest that "portals" (mountain tunnels?) are worth 15 for going through! So this efficiency score equation is the bridge between those worlds. Tiles worth more than 3 would just reduce the overall amount of tiles better than one you would need to use to get to the 100% bonus, because it would be easier to hit that 1.5756 score you need.

I didn't track the exact numbers in my last game as Inca, but it seemed to make sense that as the Inca, my trade routes through tunnels did pretty much double the value of the route. Given that a trade route is generally only 15 tiles, basically going through the tunnel gives enough of a bonus to efficiency that it will almost always double in value, unless if your route is extended through other trading posts.

 

[ggmoyang]

I did some test, it looks like a canal doesn't give +1 gold. Also, the game occasionally chooses land route over more profitable sea route.

https://imgur.com/a/JsXHxym

 

[Sostratus]

I did some test, it looks like a canal doesn't give +1 gold.

You know, I was seeing +2 gold through the panama canal and I conflated that with the two tiles on the route. It's likely the panama canal wonder itself gives +2 gold but is counted as "canal" in the tooltip.

 

[ggmoyang]

You know, I was seeing +2 gold through the panama canal and I conflated that with the two tiles on the route. It's likely the panama canal wonder itself gives +2 gold but is counted as "canal" in the tooltip.

Does it says canal rather than dumping into 'other bonuses'? Interesting. So they missed out the description... :/

I did some more tests and it looks like the bonus from transportation efficiency is applied to districts in the target city income only, which is capped at 9. (base 3, +3 from CH and Harbor)
Quite disappointing.

 

[ggmoyang]

Did some additional test. I put a city with various space with CS and made a land trade route. Then I put railroad tile by tile and checked the income increment.

Results:

With 3 spaces: 40%, 80%, 100%
With 6 spaces: 25%, 50%, 75%, 100% from 4th railroad
With 7 spaces: 23%, 43%, 67%, 90%, 100% from 5th railroad
With 10 spaces: 16%, 33%, 50%, 67%, 83%, 100% from 6th railroad

Conclusion: Game checks both city tiles, so a 3-spaces route is actually a 5-tiles-long route. You need to cover 50% of the route with railroads to get the maximum bonus.

Discussion: TRANSPORTATION_EFFICIENCY should be (sum of the value/route length), capped at 1. Since the railroad has value of 2, you need to cover 50% of the route with railroads.
Or you can say a railroad tile counts as 2 tiles. If you have 4 railroads in 9-tiles-long route, you have an 8/9 bonus.
Similarly, A mountain portal should be enough to cover a 15-tiles-long route.

 

[Tech Osen]

When you select a city for a trade route the tool tip tells you how much is added for infrastructure.

I'd love to hear people's thoughts on how useful railroads really are. I already get crazy high gold from late game international trade routes without railroads, is the increase really worth the added CO2 and eventual expenses of damaged coastal tiles and increased weather damage? I have yet to build a single railroad tile in any of my games yet.

I wish it were different but the best way to deal with CO2 is to just beeline for flood barriers and get them up before the damage comes. If you build them on time they also build pretty fast, between 4-10 turns, depending on how you set up your cities of course. (Some people here seem to be allergic to industrial zones).
If you're ahead in science then causing the sea to rise is also a good way to cripple the competition.

 

[Brutus2]

When you select a city for a trade route the tool tip tells you how much is added for infrastructure.



I wish it were different but the best way to deal with CO2 is to just beeline for flood barriers and get them up before the damage comes. If you build them on time they also build pretty fast, between 4-10 turns, depending on how you set up your cities of course. (Some people here seem to be allergic to industrial zones).
If you're ahead in science then causing the sea to rise is also a good way to cripple the competition.

Agreed. In my last game I ignored flood barriers for too long as there was no co2 at all and I wasn’t making any myself then all of a sudden coast started getting wrecked, cost of barriers increases and It seems like once it starts the next stages come quickly. Damage starts to snowball and all from one AI that had started contributing co2.

Having said that, my international trade routes to allies over water with democracy and policy cards were already generating at least 25-30 gold each turn so railroads just don’t seem necessary but I will have to force myself to try them next time.