TL;DR: I can think of lots of nice-to-have functions that help me tie multiple colonies together through Europe, but I cannot finish a game if I have to manually control carts to ensure feedstocks don't run short. This becomes a headache rather than achievement when my manufacturing yields hit ~20/turn and I have more than 5 colonies. It's not always the case I have one or two backwaters supplying raw goods to a nearby manufacturing hub, but I can work with a trade route system that allows me to specify two endpoints and the priority loads and unloads at each location.
I suppose there are two broad classes of players. Some favor trade route functionality that allows the player to integrate an entire continent into an Amazon.com logistics scheme. That is, one which has high cart or ship (transport) utilization (100/100 slots > 15/100 slots), economically efficient choice of goods ($), and transports that run from distant hinterlands across multiple stops, leveling stocks along the way, filling every valley and making every mountain low. Something intelligent enough to find goods where the player hasn’t manually specified. These players are utilizing the full breadth of the building tree, play on large and huge maps, for tens of hours. I imagine them as model train builders who like systematizing. It's a good hobby, but accommodating this playstyle doesn't strike me as what is necessary for historical economic simulation.
Of course, no one fits this description or has absurd goals for the trade route system. But I want to contrast my vision with the suggestions earlier in the thread.
The other class of player favors the minimum functionality that will let them finish a game. They neither want to manually control every transport to ensure production centers maintain minimum feedstocks, nor learn to use a new trade route system that might still drive a cart across the continent to pick up 50 “raw materials” needed no where. They infrequently use buildings past the mid-tier because winning does not require it, they play on maps smaller than large and huge, and their goals are victory conditions, not personal ones. They would be happy to have carts badly utilized, as long as they did what they were stupidly told and traveled where they be found so problems can be rectified with the ol’ manual load’n’unload. Conversely, understanding where to troubleshoot a complex route system that uses look-a-heads or upstream cities is one more hurdle in front of finishing.
My idea on what a trade route system should do is allow me to level the production yields
between two colonies. In a dream world, I would produce as many transports as necessary to obviate the difference between one colony and the next. The two colonies would sit on different tiles, have different liberty ratings, and the interface would purport they have access to different tiles and buildings, but I would consider them one colony. Food grown in Colony A would be available by the end of the next turn in Colony B, the black yield (increasing stock) in one buttressing the red yield (decreasing stock) in the other. In the real world, I will program a cart to take food from the black to the red and I will not build enough carts to eliminate all distinction between their inventories, But a trade route system should let me achieve this theoretical state.
I usually want to bring raw resources from one frontier colony to one huge city without anyone missing a deadline for tools or running out of lumber and ore. I can accept if shortfalls occur because I'm not producing enough at one of the locations for how fast the other location burns through them. I'll get the alert in the event log "Colony A is running out of Y and won't be able to produce Z." I can add more transports, or substitute transports with greater capacity, with goods from other colonies as needed. I do not need a trade route system that intelligently detects shortfalls and goes to colonies outside these 1 to 1 relationships.
I expect to set up a bunch of 1 to 1 routes that overlap. Colony C would never get tools produced by Colony A, but Colony A is dumping it’s tools at Colony B, so I, the super manager that I am, can smartly make a transport bring tools from B to C. So while I’m really beating the drum for 1 to 1 functionality, I want to acknowledge that in practice what I’m proposing is probably similar to what others have earlier in the thread, just with the emphasis that I want to finish a damn game, rather than create something beautiful.
I expect to manually ship colonists and also to run a few special errands, but I want to automate the bulk shipping, the shipping that is never wrong. Even if “automation” is a highly manual process to initiate, I favor that predictability over the non-solution that is the current vanilla system. I prefer something I can set up to prevent work stoppages to intelligent transports that care how the distance to a location affects ROI.
I would like to see the net production and net consumption of each good within the colonies I select.
The Domestic Advisor shows me all my colonies at once and one bottom line. I would like to uncheck colonies to see the bottom line for the two colonies I’m setting up to be a cluster. If I see a big deficit, I’ll automate a transport to rope in goods from some colony outside the initial cluster (of two). I will be happy to manually program load/unload what that new transport will carry. If I see a small deficit, I will bring one of the 2-5 transports I’m manually controlling into the cluster every 10 or so turns for the exogenous infusion of tools or whatever is needed.
This improved Domestic Advisor interface would help me see when I’m going to run into overstock problems unless I manually haul products out of the system. Here also the native event warnings will help, “Colony A is running out of capacity and will start hemorrhaging guns, gold, and tools tomorrow!” The timeliness of these warnings decreases as your production and imports grow, unfortunately. The dream version of this interface would let me click a right arrow to project stocks—including automated imports and exports—at each selected colony, one turn into the future. Another click would let me see two turns into the future. Another click would let me see three, and a colony will turn red when it his overcapacity, so I can send manual transports in time.
But it has to show all the goods on one page. I don’t want to click right right right, to see stone, and left left left, to see tools. The Domestic Advisor requires this. If there is no interface solution for this, I would prefer you remove good types, buildings, and terrains than make me click left and right.
I'd love if you warn the player when the net consumption of a good exceeds the net production on a route, but I'm fine watching my stocks run low and just making the necessary tweak to have net stocks grow. I expect to tweak the target levels of important goods at each colony in a cluster every few turns. Afterall, each turn terrain improvements are finished, buildings complete, and colonist productivity increases.
If the system does have the relatively dumb A-to-B functionality I propose, please let me click once to "assign all goods to export down to 0." I will manually change the food, tool, horse, etc. target to 50. But I don't want random gifts from Natives, errant pirate plunder, and other goods to accumulate because I didn't go out of my way to export furs from a colony with no forests.
Priorities:
- Colony-based minimums. I need to reserve quantiles of goods for that colony. I am happy to define this numerically, for each colony, without a template.
- Cart or ship remains where you might expect it: end point, start point, or in transit between them
- An interface that helps me see the net production of all goods between as few, or as many colonies at once. Or rarely all colonies at once, as the Domestic Advisor does.
Not Priorities:
- Transports that know about future trips
- Transports that know about other transports
- Transports that know about colonies other than mom and dad
- Good cart or ship capacity utilization ()
- Economically efficient choice of goods ($)
- Guard units
- Waypoints
If it makes implementation easier or quicker, assume:
- Player wants to automate the shipping that's never wrong, not all shipping
- Player won't set up routes that supply insufficient production of any good for the consumption of that good within the trade route. If he does, the event log will alert him about it.
- Player cares most about avoiding overcapacity losses
- Player cares less about economic efficiency than a colonist he placed in a building running out of what that colonist consumes
- Player wants trade routes to hoover up all the errant goods across his empire.
- Player manually controls export from 2-3 major port colonies to Europe, Africa, and Port Royale.
- Cantankerous-to-use > difficult-to-understand > current system