Hi there fellow Tropican.
El Presidente recommends building more than one road to ensure the exchange of goods.
Because one road, no matter how many lanes, will always get stuck at a certain point, especially if it is the only route for goods and to the (main) dock.
So make sure you have several routes and roads to ensure the best possible infrastructure.
-cheers

Dear Dev. i have set up triple road systems to try and alliviate the issue and still run into the problem depending on the map shape and restrictions. i know the idea of multiple over crossing roads help but it also backs up traffic with the frequent stops. thank you Dev for hearing my idea and looking forward to a possible tropico 6? i would buy with a new economic road/exchange system