What kicks in foreign trade routes?

[stormwriter]

I noticed all my cities only had domestic trade routes, and that concerned me. Then i forgot to do Open Borders with the other civs.
Duh.
But then the trade routes STILL didn't appear.
Oh, forgot Astronomy for trading on the ocean...
Duh. (cause i was alone on a continent...)
Trade routes STILL didn't appear.
It wasn't a civic i was using.
I didn't know WHAT was going on! I must have gone 1000 years before all-of-the-sudden some finally appeared.
I would like to know what, if anything, made the foreign trade routes appear. I know they are "automatic", but it wasn't quick enough for me.

[solo]

I think an unbroken path must be made by a ship from either the source or destination city's civ to establish a new trade route.

That is why I build a galley and send it looking for AI cities when I build the Great Lighthouse. As soon as a new city is found, it pops up the turn after as a trade route, if there is still an open slot. Or it may replace another city previously being used. Don't forget to establish Open Borders at first contact, which I believe are also needed to start the trade routes.

Astronomy may be needed for routes without connecting coasts all the way from one city to the other. Again, I think a path must be established by a ship to get the route going. These pay better, I think, because they are classified as overseas trade.

It can be a long wait to get routes if you leave it up to the AI to find you.

[stormwriter]

Solo, you're probably right! Cause i hate building ships, so i sat there on my continent all alone, and never sent one ship out! haha.
I wonder if i can send ships out and establish the trade route, but keep my borders closed for a bit? (until i settle in my territory, so the AI doesn't plop a settler in my area.)

[solo]

I'll have to check that out. I know that existing trade routes of mine were preserved (or maybe established, I'm not positive) without an Open Borders agreement with one of the AI.

[MattPilot]

Also notice that foreign trade routes are limited. YOu can only have one trade route with each foreign city. Domestic routes, on the other hand, are unlimited.


So perhaps you were looking in the wrong city? Foreign trade routes only pop up in the places where it earns you the most money.

[mgdpublic]

Solo, what do you mean by "unbroken path?" Is that just mowing the big black lawn with a ship or do you have to enter the foreign city with the ship?

[solo]

All I had to do was reach the AI city's culture border. If you are close enough, they will start a diplomatic session. I didn't need to actually be next to the city, itself, to get the trade route started.

By "unbroken path", I meant mowing a lawn from my city to their's, but in another game since, I noticed that this path may need to be along the most direct route, too, since I couldn't immediately connect up a city I found after meandering around to find it from the back side. I have to play a little more to know for sure.