Having acquired the licenses, they then experience crash rates typical for their age, and as a consequence end up with more crashes than if they had not received driver education. Although the interventions involve training, it is not clear that the mechanism producing the crash reduction is the knowledge acquired, or the experience of detailed interaction with the authorities. The effect may be more in the realm of enforcement and deterrence rather than education and training. Post-licensure training programs have not been shown to reduce crash rates. They conclude that, while the methodologically strong studies show a decrease in the frequency of traffic violations, no consistent effect on crashes is apparent.
Some states require drivers with multiple citations or crashes to attend such courses.
Others require automobile insurers to give discounts to graduates of approved training courses. Clearly, if there was convincing evidence that such courses reduced crash rates, then discounts would be given as part of the actuarial process without the need for compulsion. There are presently widespread efforts to increase training programs for older drivers, with a move to provide compulsory insurance reductions for graduates without any evidence that the programs reduce crash rates. A possible reason why training and education do not lead to clear changes in safety is that so much of the skill and knowledge they aim to impart will be learned by trial and error, and by experience. Without instruction, drivers will learn how to negotiate corners, park, back and perform all the repetitive tasks based on experimentation and feedback.