All it takes to solve your traffic problem is to designate the roads around your mall into three different types and build along them accordingly: Arterial (Red wavy line), Collector (Green zigzag), and Local (Blue straight line).



Arterial roads connect to the outside world, which means extreme heavy traffic. Do not build parking or any other vehicle uses for these roads, only intersections. This is important! These roads only move cars into and out of the map.

Collector roads intersect with Arterial/Collector roads and Local/Collector roads, giving cars multiple paths to choose from and having moderate traffic. These roads are good for parking spaces and OK for loading zones, but bad for garbage areas and bus stops, as buses and garbage trucks will block even moderate traffic.

Local roads are the destination roads - cars on these roads are either coming here or leaving here. Nobody needs these roads to travel to another road; because of this, there will be minimal traffic. These roads are for any use, but they are the only place you should be putting garbage areas and bus stops. Keep that in mind.


OTHER TIPS:

-Cars in this game, like in real life, will "rat run" through local roads if they think it will be even
a little bit faster; this is a good thing in our system because it spreads cars out evenly onto different Collectors, preventing any one Arterial/Collector intersection from becoming a choke point.

-Build garbage areas far from your Collectors/Arterials (this may be in the middle, if your Local road intersects at both ends). Garbage trucks take by far the longest to load, so making sure nobody will ever need to pass them is helpful.

If you think about this hierarchy every time you build a new road, you will keep traffic under control!

I hope you are enjoying this game, and I hope that my guide helps you to enjoy it even more. I will update it with good comments or if I wake up in a cold sweat because I forgot to include something important.

Further reading from the United States Department of Transportation on road hierarchy:
https://www.fhwa.dot.gov/environment/publications/flexibility/ch03.cfm