I appeal to those who are really interested in the question of the effectiveness of driver education to unite and produce the sound evidence that's lacking. In our society, any human being starting to engage in performing a new and complex task gets training and education. Driving can't be the exception. At the most primitive level this involves a process of conditioning reflexes like the dog that begins to slaver at the sound of the food tin, or the driver who turns his head in the direction of the horn. Typically human is learning by understanding.
People learn best when they understand why something is worth doing in a certain situation.
People need to consciously process the knowledge which tells them what to do. The associative, or rule-based phase. After a while, knowledge is fully translated into rules, which are triggered quickly and smoothly, without thinking. Finally, the autonomous or skill-based phase. Actions follow situational stimuli automatically, and then we can say that people are skilled performers.