I already play for a few weeks now, just some tips from me, the best and faster solution to export, import and deliver some raw material is use Freight Train Cargo, you can separate the railway between cargo and public transport railway or you can merge the railway to cut some extra money to purchase the railway. You can also use truck to the main highway or use cargo ship in cargo harbor but these 2 solutions is little bit slow. Why? :
-Trucks will make more traffic flow and sometimes it can make traffic jam and slow the delivery process (even you make the public transport free).-Cargo Ship is little bit slow and it must near to the beach so it can operate normally.