So, you have finally set up a complete cargo line!
However, after a while economy stops producing; your vehicles make nearly empty runs; one of your trains is waiting empty next to an oil refinery that has a full storage but tells you to "carry away more oil" (!?), all while your company makes millions of losses!
Now before you start punching your monitor, because the oil refinery man just metaphorically spat in your face, keep reading and bring some towels to clean your monitor.

This guide is also useful for people using bland "spam vehicles"-tactics in easy mode to play in hard difficulty.

Before we start fixing your cargo-chain, we should make sure you did not forget to plug in your broken vacuum cleaner, first, shall we?
So let's go over this simple check list first, essential for every cargo chain! After that we can get down to business!

1. Your produced wares are sold somewhere!
   It is essential for the economy to work and therefore for your transport network that the end products are sold in cities at the end of your cargo chain. Otherwise producers will just stop producing as soon as their internal storage gets full and not reorder any more materials.
   Cargo will poof into existence at raw material producers and poof out of existence in cities only!
   
   
2. The catchment area of your city-depot covers the correct districts!
   By turning on the "districts view" in the bottom right corner and clicking on your depot located in your city, you can check if you are covering the correct buildings of your wares to be sold.
   - Industrial (yellow) takes construction materials, fuel and machines
   - Business (blue) takes food, wares and tools
   
   
3. You are using the correct vehicles!
   Trucks can transport everything but passengers and you can't use planes for cargo.
   Make sure your ships and the waggons of your train are actually capable of transporting the desired goods.
   
   
4. The catchment area of every depot is in range!
   Sometimes when building depots it highlights a building to be in the catchment area even though they are not. Countercheck if this is still the case after placing depots.

Great! You have now set up everything correctly. Well despite the fact that your cargo chain is still running poorly and the jobs of millions of minature families in your virtual world are still endangered!!! I hope you are panicking a lot because you should!
"Mommy, why don't we get a christmas tree this year?"
"Because the giant looking at us from the sky has utterly failed my sweet child, because he has utterly failed!"
Let's get down to business, shall we?

The game calculates the capacity of your transport network, and is comparing it to its current usage.
If your trucks at the rear end of your transport network i.e. can't hold up to the previous transport lines then wares are piling up until those trucks are considered "in use" and the "Line usage" flips to "No".
This leads to the fact that your ship at the very front of your transportation network doesn't get any ressources any more even though the economy shows a "Potential" and tells you to "carry more" - and it is right!
Your ship then makes an empty run, meanwhile your bottleneck trucks complete their task and "Line usage" flips to "Yes" again - however your ship at the very front is arriving completly empty and all of your lines keep making empty runs until your ship has made a complete trip again.
And your ship is only given at max as much ressources as your transportation network can handle in the first place (--> your trucks are the bottleneck again!) plus an overhead.
Even if your ship is set to "wait until full" it is leading to a delay in economy that spreads like a wave through your whole transportation network.

Now, bring your calculator or open the calculator app on your smartphone or PC because we need to do some math! Trust me, this will solve your stuck economy forever.
This is also essential to compete in hard-difficulty, squeezing out as much money from your transport lines as you can.

We just need one self explanatory formula to analyze your cargo chain:
and then we can compare the results.

If this chapter is too much math for you, skip to the next chapter "For Starters" to keep it to a minimum.



First of all let's have a look at the city demand by clicking on the name of the city. This demand is given in "wares per virtual year", now all we need to do is calculate it into a usable number.

An ingame year takes approximatly 12 minutes.
Taking this and the values from the city in the picture, the industry in this city wants
Do this for your city in your game as well!
We have to keep this value in mind because we need to compare our cargo chain with this value!



So how much can our existing cargo chain actually transport?
In order to find this out we have to open the line-information menu in the bottom left corner
We want to transport fuel to the industry in the city by transporting raw-oil to the refinery by train (cargo line "B1"). The produced fuel is then transported by trucks (cargo line "B") from the refinery into the city.
The important number is the "frequency" (Freq.) on the right and the number of vehicles as well as their overall cargohold to the left of it.
Both lines have a capacity of

The frequency doesn't tell us the frequency (@Developers: Seriously?) but the average time interval the next vehicle of this line is going to arrive at one of our stations after the last one.
If we multiply this value by the number of vehicles, we know how much time it needs until all vehicles of this line have visited every station once.
If we have just one vehicle, like our train in this example, the interval is equal to the time it needs to make one full trip - of course!

Note: You need to setup a line before you can tweak it. There is no way to set it up correctly from the beginning on because of the missing "frequency" value you never know how long a vehicle actually needs.



A very good transport network has an increasing cargo-stream from the very first producer to the city and is below the cities demand!
Ideally you want that every transport-line in your network has a cargo stream exactly equal to each other and city's demand, however this is impossible to accomplish /!\.

Note: An economy that gets stuck has at least at one point a bottleneck compared to the previous transport lines.

Let's have a look at the values from the example above
Our trucks cargo-stream is greater then the cargo stream of our train (0.177 > 0.168), this is good!
However the city's demand is below the cargo stream of our network (0.118 < 0.168), that means our trains and trucks aren't under full load.
This is not that bad because as cities are growing over time, demand is going to increase. Just make sure the difference is not that high.
Still, we are losing money!

A stuck economy has a transportation network like this
or like this

Note: Machinery needs 2xWood to produce 1xTools - "0.7" is actually good /!\
The transport line between saw mill and machinery should be between 1.2 and 1.4, however.


And here we go! *choo choo*

Now that was a lot of math, wasn't it?
For people who just started the game or have "lost" their calculator, the easiest line to setup without much math is a single transportation line.

Let's have a look at the very first entry here.
Line 'A' consists of seven trucks that are transporting raw-oil to the refinery as well as bring the produced goods to the city in one run.

The only thing you need to calculate is if your trucks are as close as possible to the demand.
The city's demand in question is 144/year that is
and our trucks are delivering
taken from the line information menu in the picture.

Perfect!
It is simple as that and we have maximum profit!

One last thing. The tolerances.

1. Displayed Frequency accuracy
   As you have probably noticed the frequency is only given in minutes by the game when the value would be too large in seconds.
   If the line information menu shows our train needs 4 minutes it could actually be a real value between 3.5 and 4.5 minutes.
   
   
2. Traffic
   Traffic and traffic jams on one of our lines can lead to a temporary delay, leading to a temporarily jammed economy.

The game already seems to take these tolerances into account to some degree.
Just make sure that you have a visible increase in the cargo stream capacity to your previous line.

Have fun!