Traffic Lessons From Army Ants

Feb. 16, 2005 -- -- Human beings could learn a thing or two about traffic from army ants. A study by researchers at Princeton University in New Jersey and Bristol University in England found that army ants create lanes of traffic that flow quickly and efficiently.

The study, published in the Proceedings of the Royal Society of London, Series B, in January 2003, says that the ants use pheromones to create paths and follow a very simple set of social rules regarding things like who has the right of way. They create three lanes of traffic -- outgoing ants in the outside two lanes and those returning to the nest in the middle.

Despite the tens of thousands of ants that may be on the move simultaneously and the fact that they're essentially blind, they're still able to maintain an even and mutually beneficial pace.

Human beings display similar behavior -- minus the pheromones -- when walking in large crowds. But all the rules seem to go out the window when we get into our cars and head into traffic.

In evolutionary terms, ants have an advantage over humans when it comes to traffic because they rely on genetically inherited behavior to keep things moving, rather than traffic laws.

Army ants "can evolve the best strategy for everyone in the population -- the one that maximizes the rate of flow along the trails," one of the study's co-authors, Iain Couzin, said in a telephone interview. "We unfortunately have to use our intelligence to create traffic rules and so forth, to try and decrease congestion within our society."

For ants, it's simple: do your job and do it right and all the ants in the colony will benefit from it.

But for humans it's a bit more complicated.

People don't always follow the rules, and rarely are they thinking about how hitting their brakes or making an unnecessary lane change could impact drivers that are far behind them.

"The wonderful thing about being an ant is that they're working together for the benefit of the colony," Couzin explained. "The problem with us humans is that we tend to be a little selfish."