Speed cameras: how did the lottery turn out?

Last month I blogged about an experiment in Sweden where a speed camera records all the cars keeping to the speed limit with all the legal drivers going into a prize draw for cash prizes.

The trial has now been carried out and here’s the result (quick version – the average speed of traffic fell from 32 km/hour before the trail to 25 km/hour during the trial):

Hat-tip: the Nudge Blog