all city tiles trading amount together to upgrade the trading headquarters ?

[northfly 5]

To upgrade the trading headquarters, you need increase your trading amount, right? I am wondering one city tile may not be enough to get that high trading amount to be able to place three sub-trading headquarters.

 

So I am wondering if the whole region's trading be counted to do so? Thanks.

[tnobles 38]

Yes the trade HQ, Metals, Petroleum, City Hall, etc. will all work that way. Any city with the particular upgrade will be across the region.

[Jtex 0]

It is just 1 city that counts, and you can do it on a tile with water and the  cargo ship connection addon to the port(no traffic and the ships haul a lot). The best way to do it is to make sure you have enough simoleons on hand to keep your city running for a few game days. Make sure you have enough storage for the item you will export, I find alloy or processors to be the best items for this. If you dont have the trade port you may need to use multiple depots but can fall short on unlocking all 3 sub hq's if traffic is too bad.

 

At the start of a new day(12am) put your global market to use locally. Stack the item you are exporting for a day or even longer if you need to. When you think you have enough which I believe is about 6 mil in trade set global to export at the start of a new day. Make sure you trade hq is turned on at this point.  All the trade for that day will count toward the goal, and if it all gets out of your port or depots by the end of the day you will unlock all 3 sub trade hq's at once. You will often also  unlock the full upgrades for the hq's  of the  items you used(alloy=metals etc..). If you come up short try again with more storage or clear traffic for you trucks to get in and out of the city with the goods.

 

Good luck and have fun.

[Rufus Honker IV 100]

I am wondering one city tile may not be enough to get that high trading amount to be able to place three sub-trading headquarters.

 

This is probably true.  I'm assuming the brunt of EA's playtesting assumed we were playing in mature regions with several people working on building up trade - they figured one person with a trade HQ would plop one addition, a different person with a trade HQ would plop another.  They weren't counting on all of us rugged individualists who play alone.  Hence getting one single city to plop all three of the trade HQ's addons wasn't really in their expectations.

[Jtex 0]

I've plopped them all using the method I posted with no problems.