How to plan hugh traffic areas

[odd roost]

That is a huge question. First you have to think about, is import of goods needed? What should stay inside the city?

The problem with the industry in CS is, that no matter which kind, traffic is the same, for agriculture as much as for oil

Without mods you cannot control the routes. Or which of the warehouses with the same goods get chosen

You have extractors, those goods get either transported to the processor, a warehouse for this good or exported

Well, the behaviour of a warehouse depends mostly on wether it is set to empty, full, or balanced

Export means out of the city

Well of course a warehouse would also sent goods to a factory outside of the industrial era which does need those good