Thomas Barois (Laboratoire Ondes et Matière d'Aquitaine, Université de Bordeaux). Traffic jams and active particles.

The time spent by drivers in jams during commuting hours can be quite significant in urban networks such as it is for Bordeaux or Paris. In my opinion, the drivers should enjoy these precious moments because they are actually participating to a massive physics experiment of interacting active particles and they have the chance to be one of the individual ‘microscopic’ elements of the system.

In this talk, I will first present the general features of the transition to congestion in road traffic. I will show that most of the observations about the traffic on roads and in urban networks are somehow counter-intuitive, if not paradoxical.

In the second part of the talk, I will present some recent results we have obtained with self-propelled robots circulating in a simplified road-like geometry. The objective of this experiment is to question whether an ensemble of ideal self-propelled particles provides a fair representation of the transition to congestion in complex systems.