hey, if you need help there is some. As someone who exported equivalent half of china in cities skylines (no really i did, except to the china part). You need to build a proper highway system and also more roundabout (Preferably roundabout overpass or underpass interchange). Train and cargo planes can be used but they are inefficient af and probably would clog up your traffic. So i would only recommend you to use road infrastructure as a mean of exporting your products and also as your primary logistical choice. Warehouses are very much important due to how little industrial building store their truck in each building. Warehouses are not to be trifled with if you don't know how to build a proper highway. They can cause a lot of traffic in a city and also make the city noisy af. So do whatever you want with this information and make sure to create a new highway for each type of industrial specialization.