Ant Traffic

Ever wonder why ants don't experience traffic jams? First rule of ant traffic: no overtaking.

Physicists and motorists alike have long puzzled over the tremendous complexity of behaviour that emerges in one way traffic flow. Who hasn't been stuck in a jam with no apparent cause and that suddenly evaporates for no obvious reason?

Physicists have long known that these effects are closely linked to the density of traffic. Below some traffic density threshold, the flow is always smooth; but creep above this limit and all kinds of traffic chaos ensues.

Now Alexander John at the University of Cologne in Germany and few mates have studied the traffic flow along trails made by Leptogenys processionalis, a more or less average species of ant.

And what they found is quite extraordinary: the average speed of the ants remains constant, regardless of the density of the traffic. There is no transition to a nonlinear flow, at least not in the conditions that this group studied.

Let's put that in perspective. Ant traffic flow is like rush hour traffic on the New Jersey Turnpike travelling bumper-to bumper at the 55 mph.

So what's the secret? John and his mates aren't entirely sure but they've found a pretty good clue: ants never overtake. Not ever.

Let that be a lesson to you commuters.