Why ant colonies don’t have traffic jams

ant-motorway

Traffic jams are the bane of modern life. But could it be possible that one of this planet’s more ancient life forms could show us how to better regulate road traffic?

That’s the claim of congestion expert Dirk Helbing at the Dresden University of Technology in Germany and pals using a remarkable insight gained from the study of ants.

It turns out that ants are able to regulate ant traffic with remarkable efficiency. Let’s face it, you never see ants backed up and idling along a pheromone scent trail. On the contrary, ant colonies are a constant blur of organized and directed motion. How do they do it?

To find out, Helbing and pals built an ant motorway with several carriageways between a nest and a source of sugar. The carriageways had several interchanges where the ants could switch between longer and shorter routes.

Some ants soon found the shortest route to the sugar and others followed the pheromone trail they left behind until this shortest route became saturated with ants going to and from the sugar.

Then something interesting happened at the interchanges between the carriageways. When the route was about to become clogged, the ants coming back to the nest physically prevented the ants travelling to the sugar getting on to the highway. It wasn’t a conscious action, there simply wasn’t room for two ants to pass at these congested spots. So these ants were forced to take a different route.

The result was that just before the shortest route became clogged, the ants were diverted to another route. Traffic jams never formed.

That’s an impressive feat because the efficient distribution of limited resources by decentralized, individual decisions is still an open problem in many networked systems. As Helbing puts it: “This is one of the most challenging problems in road traffic and routing of data on the internet.”

But one that ants seem to have cracked and this gave Helbing an idea. Obviously, you can’t allow cars to collide with vehicles coming in the opposite direction as a form of traffic control; but you could do the next best thing and allow them to communicate. His plan is to force cars traveling in one direction to tell oncoming vehicles what traffic conditions they are about to encounter so that they can take evasive action if necessary.

And it’s not just road traffic that might benefit. Helbing speculates that all kinds of routing processes could benefit from a similar approach.

Simple really, if you’re an ant.

Ref: arxiv.org/abs/0810.4583: Analytical and Numerical Investigation of Ant Behavior Under Crowded Conditions

10 Responses to “Why ant colonies don’t have traffic jams”

  1. [...] schon: wie sich herausstellt, kennen Ameisen keinen Stau. Eine nette Einführung zum Artikel gibt’s im Blog von arxiv.org (auf Englisch). Written by Jan in: Uncategorized [...]

  2. [...] van todo en fila pero sin crear atascos ni nada. En este artículo se explica el motivo. via:arxivblog.com/?p=690 sin comentarios en: cultura, ciencia karma: 13 etiquetas: física, comportamiento, tráfico [...]

  3. [...] | ArxivBlog Más noticias sobre: Biología Tags: comportamiento animal, comunicacion animal, [...]

  4. Kent says:

    Traffic congestion costs the world’s economy on the order of billions each year. That’s not including the contribution to green house gas emissions, the mental health of all people caught in traffic jams, etc.. Therefore it is imperative that this problem be solved as quickly as possible.

    Relying on the decentralized individual to solve this program is way too idealistic. We must have a centrally organised system. All we have to do is use GPS systems in cars and then have a centralised system control the traffic flow by physically blocking off overly congested roads and providing optimised routes to the drivers of the vehicles. Since it is a non-linear system, if we have such a system in place for 50-60% of the vehicles, it would already make a huge difference.

  5. Cellar says:

    On what grounds “must” we have a centralised system to achieve what apparently can be achieved in decentralised fasion? I’d like to hear your reasoning on this.

  6. Marcus says:

    How many pedestrian traffic jams have you seen?

    Almost nothing that can be learned from ants will be useful in avoiding traffic jams with cars. The reason is that ants, like pedestrians, can walk along almost any path along a surface. If there is a blockage along a path, they can go around it and try to find a new path. Cars cannot do anything similar because they are largely constrained to a unidirectional 1D path, especially on highways.

    That is why highway traffic can be modeled quite well by physicists: it is essentially a 1D model where each agent can be described by very few parameters. The jam/no jam scenarios can fluctuate in time, and often don’t have a static cause (such as an accident). Instead, they are often driven by near collisions, and the backward propagating waves that ensue.

  7. john wolf says:

    trying to get a copy of ant motorway jpeg

  8. KFC says:

    Re-uploaded. Should be there now.

  9. [...] on two way traffic in which head on encounters between ants dominate the dynamics. We looked at one such study of bidirectional ant traffic not so long [...]