Hi all,
I have a 450k-ish city, I feel pretty well laid out between zones. However I am being killed by how many "Not enough Goods to sell" messages in my commerical areas, combined with "Not enough raw materials" in my industrial". Traffic floats between 65-70%, pretty good highway access, ports and outside connections, three airports and train stations scattered through out the city. Bus lines and some tunnels/trams set up as well.

Any ideas?

Image Link incase want to see a view of the city: https://ibb.co/Gnf4nFM