So it turns out ants are smarter than humans when it comes to traffic, despite their tiny, oh-so-squishable brains. Dr. Helbing of the Dresden University of Technology set up two 'ant highways' leading from a nest to some sugar syrup. One was shorter than the other but narrower. When the thinner route got congested, a returning ant would bump into one just setting off from the nest. This would redirect and lead all the ants following it onto the other path until congestion eased. Based on this, the research team set up a computer model of a more complex network and found that the ants, even though they sometimes took a longer route, still were pretty much as efficient as they could be.
Pretty cool, but I'm not sure it'd work on our roads- when cars bump into one another it's usualy fairly disastrous.