Drivers who were free of collisions and convictions over a one year prior period were sent a letter notifying them of a 12 month licence extension issued as a "reward" for this accomplishment. They were also told that at the end of the following year should their records again be clean, they would be re-contacted and given a second extension. The results of this Reward Program indicated no reliable influences on subsequent traffic convictions an various detrimental effects on subsequent collisions compared to un-contacted controls.
Abstract