In the current version of the game, caravans do not exist (and so portage is a useless idea at the moment).

Transfer of resources can still be easily done from territories to regional centers through internal transfers (the old button for trade) as soon as gift economy is replaced with barter, and is free.

Internal inter-regional trade is best done through internal orders through the market.

Free Traders will also buy goods at 80% of the world's average minimum price from any player, and resell them at 200% to any player. Goods do not appear out of thin air, and must first be sold by somebody in order for it to appear.