Contribution of the components of graduated licensing to crash reductions

It has been established that graduated licensing systems lead to crash reductions among beginning drivers. What is the contribution of the various components of graduated licensing to these reductions, and how can their effectiveness be increased? Literature review and synthesis. Extended learner periods, nighttime restrictions, and passenger restrictions have contributed to crash reductions. Presently there is insufficient evidence concerning the contribution of seat belt or cell phone provisions, or contingent advancement penalties. There is more to learn about graduated licensing and its component features. However, there are ways to increase the contribution of all the components through stronger laws and greater compliance. With the right kind of community commitment and focus, substantial further reductions in young driver crashes are achievable. The results can guide states in establishing graduated licensing systems that maximize crash reductions.