By looking into the GPS information, from vehicles (collected) in Italy, Gallotti et al have performed a study to apply ideas of statistical physics to describe the properties of human mobility.

The human mobility is an interesting research question. Understanding of human mobility can be useful in urban planning, and to understand spread of epidemic. In addition, the authors suggest that such studies may also be useful to discover possible "laws" that can be related to the dynamical cognitive features of individuals.

In the paper, using the travel time as a cost function, the authors show that the distribution between successive trips are indeed driven by an underlying Benford's law. The ranking of the the distribution of the average visitaion frequency may also help to understand how people organize their daily agenda. An interesting feature comes out when the average speed distribution for the recorded trip is decomposed as a mixture of two Gaussians: one with ≤ 5km. I think such characteristics distribution indicate the local constraint on the movements. Obviously, the motion is not free of constraints. The mobility data is strictly constrained by the road structures.

It would be interesting to see if there are such statistical phenomena as "phase transition" in such statistical law of human mobility.

This is an interesting paper. See [2].

At last, Why do we move from one place to another?

If we assume some aggregate effect on social scale; are we different than the gas molecules contained in a box? Moreover, it seems someone has to drive an extra mile since the system demands it!

References:

(Special thanks to Prof. Armando Bazzani for allowing me to use the figures.)

[1] http://en.wikipedia.org/wiki/Statistical_physics

[2] Towards a Statistical Physics of Human Mobility

Riccardo Gallotti, Armando Bazzani, Sandro Rambaldi

http://arxiv.org/abs/1207.5698