Really looks like the nervous system in the human body (a bit "chaotic" too)

"One month (October 2009) of traffic information (1534 vehicles) is condensed in a 24h day. The arteries are colored in a away capable to represent average traffic speeds (the greenish and cooler represents high traffic velocity, and the reddish and hotter, corresponds to sluggish traffic). There is a visual emphasis on areas where the traffic is predominantly slow."