you have described it well. The Perimeter Loop / I-285 used to be the only place that was pure mayhem. Now it is all over the city.
I have passed state troopers in a line of cars going over 80 mph in a 55 mph speed limit. I've sat side by side with local police at 20 mph over the speed limit. On side roads coming out of my office it is 45 and cars and semi trucks are going over 60 mph. When the light turns green you have to hesitate a second because at least 5 cars are going to blow through the red light. The yellow light is meaningless. Actually yellow means floor it. Red means consider braking a little if you checked for cops.
I say this all in good humor because it is not always like this, but a lot of what I said is everyday business. I've had several Prius go by me like I was sitting still so even the tree huggers get uppity in this traffic. Even the gun haters will pull a gun on you.