Observation selection effects and anthropic reasoning
http://plus.maths.org/issue17/features/traffic/index.html
website www.anthropic-principle.com
"If you are driving on the motorway and think of your present observation as a random sample from all the observations made by all the drivers, then chances are that your observation will be made from the viewpoint that most drivers have, which is the viewpoint of the slow-moving lane (where more cars are likely to be).
In other words, appearances are faithful: more often than not, the "next" lane is actually fasterAdopting a thermodynamics perspective, it is easy to see that (at least in the ideal case) increasing the "diffusion rate" (that is, the probability of lane-switching) will speed the approach to "equilibrium" (where there are equal velocities in both lanes), thereby increasing the road's throughput and the number of vehicles that reach their destinations per unit time
in understanding this problem we must not ignore its inherent observation selection effect. This resides in the fact that when we randomly select a driver and ask her whether she thinks the next lane is faster, more often than not we will have selected a driver from the lane which is in fact slower and more densely packed(coz slow lane is denser-->one is likely to select a driver from the denser, more populated set/pool than not). When we realize this, we see that no case has been made for recommending that drivers change lanes less frequently in order to speed up overall traffic flow"