A long long time ago, I stumbled onto the personal website of a guy who was really into this. He had little simulations of different types of traffic patterns, and how a single car could break it and return it to normal. It was really interesting, but I don't have the slightest idea on how to find that website again if it even still exists.
EDIT: Found in the comments, this may have been it. Honestly don't remember: http://trafficwaves.org/
This was one of the first sites I remember finding, in the late 90s. Back then it was hosted on the personal website provided by the author's dialup ISP, eskimo.com, as I recall.
Edit: I just noticed it still is hosted by eskimo.com, it just has its own domain now.
EDIT: Found in the comments, this may have been it. Honestly don't remember: http://trafficwaves.org/