How does Commercial and industrial district work?

[Red]

I literally build a commercial and industrial next to each other, I also got enough industrial area and some 5 stars industrial area like oil and farming around the map, got transport train links to each other, how does my commercial building still said nothing to sell, industrial area said there's no buyer???

[MarkJohnson]

It sounds like you are making way too much of both.

Not enough buyers means you are over producing industry (good products) and it can't export fast enough and/or commerce is too far away and can't get freight on time and commerce goes abandon, then commerce complains there is not enough goods to sell.

You should build commerce and industry right next to each other and on the highway, so freight can get in and out quickly.

There's a simple formula for yellow ZONED industry and blue ZONED commerce:

Low density commerce (LDC) = low density industry (LDI)
High density commerce (HDI) = High density industry (LDI)
1 HDI = 4 LDI
1 HDC = 4 LDC

Also

1HDC = 1HDI

These will feed each other if in close proximity with clear traffic. Traffic will be the hardest part. If you get too much traffic it will slow traffic so much that deliveries will be late and they will start complaining until they finally go abandoned.

When they start abandoning, then you may need to add cargo stations (Trains, Planes, and Shipping) to export excess freight traffic. or stop making more commerce and industry and maybe reduce them.

When adding Industries DLC ploppable buildings, you will be adding more industry freight and it can create a lot of extra freight and really start complaining badly as there is no Commerce DLC to counter Industries DLC. You may need to dezone some yellow industry.

[OneJasonBradly]

Commercial buildings needs "goods" to sell which mainly come from generic manufacturing or off map connections. Generic manufacturing is part of the vanilla game. It is industry without specialisation.
Industries buyers come mainly from off map connections too.
If you have generic industry and still are having these issues I believe you are having a transport issue. Improve your industries connection to highway access as well as commercial.
If your traffic flow is low that could be half your battle.
https://youtu.be/_c0uHsDR4vY
https://youtu.be/ylZpemm5dE8
These are to show you can have large industrial districts and have them run well but must account for traffic.

[buda atum]

One solution is warehouses.

Ones near industry set to empty, and ones near commerce set to balanced help a lot with storage and distribution.

They however introduce more traffic, which can be devastating if not managed.

I must say, this is one aspect of this game I love so much, as it shows interconnectivity and a working simulation, as opposed to what (doesn't) happen in 2 last I checked in May.

[Challenger™]

The trick to Industrial success is not with inner city commerce but in exporting. The demand bar in the "game" is mostly just a distraction and a lie. Commercial is not just unnecessary, but actually quite unpopular with most of your citizens. CS citizens don't mind shopping, but actually hate going to work in local city commercial businesses. Can't say that I blame them. My first retail job was in a local grocery store. Wasn't much of a job then and still isn't much of a job today. Total dead end.

If you're one of those who enjoys the challenge of doing things the hard way and fighting an uphill battle then stop crying an R.I.C.O. your way into the retail market. Otherwise ...

Set up your industry to export by train and make any inner city commercial secondary. I personally do not zone any (0) commercial or residential, until all four industrial areas are running at over 100% efficiency, shipping only by rail, all city infrastructure is fully in place and the city bank account is something in excess of one billion.. I NEVER let industrial traffic enter the city.

You can of coarse do it the old slow vanilla way if that's what you're in to or you can do it, as fast as you want by simply using the

https://steamcommunity.com/sharedfiles/filedetails/?id=725555912&searchtext=goods

which greatly expands your industrial capabilities.

I've done it both ways, vanilla & mods, works equally well either way, choice is entirely up to you.

In the end, however, it still always comes down to a matter of pathfinding and the very limited options the Fin dev's possess the knowledge, inclination and or skill to provide.