A team of researchers from institutions in Germany, India, and Japan discovered this surprising result while observing the ant species Leptogenys processionalis travel down linear trails. Like many other ant species, these ants form trails with their pheromones that remain stable for hours or even days, making the trails analogous to vehicular highways.
“Our study clearly demonstrates that ant traffic is very different from vehicular traffic, in spite of superficial similarities,” Andreas Schadschneider, of the University of K?ln and the University of Bonn in Germany, told PhysOrg.com. “It also raises a fundamental question: how do the ants achieve practically ‘free-flow’ up to such high densities; our experiment demonstrates what happens and we also make a theoretical model of what might be responsible for this behavior.”
wow goldTo observe the ants in their natural setting, the researchers set up video cameras at sections of 10 different one-way trails that had no intersections or routes that branched off. Surprisingly, the scientists never observed individual ants speeding up to overtake another ant in front; the ants followed each other in single file. This behavior, of course, contrasts with vehicular highway traffic, as well as most other known traffic forms.
Most significantly, the scientists found that, unlike vehicular traffic, the average velocity of ant traffic remains the same in spite of increasing density. Consequently, the greater the density, the greater the flux, so that more ants travel down the trail segment in a given amount of time. In contrast, vehicles on a highway tend to slow down when the traffic density increases, eventually resulting in a traffic jam. Along the same lines, the researchers noted that most types of high-density traffic exhibit mutual blocking, in which a vehicle is prevented from moving by neighboring vehicles and also contributes to the blocking of those vehicles. However, the researchers did not observe mutual blocking in the ant trails.
wow goldAs the researchers suggested, perhaps evolution has optimized ant traffic flow, since ants are known to have highly developed social behaviors. In their study, the scientists observed that ants tend to form platoons in which they move at almost identical velocities, allowing them to travel “bumper-to-bumper” while maintaining their velocity. At higher densities, platoons merge to form longer platoons. But because their head-distance remains the same, traffic still maintains its same velocity even as density increases. This behavior is very different from highway traffic, in which vehicles close together tend to slow down.