1.1 Graduated Driver Licensing
GDL is a three-phase system for beginning drivers, consisting of a learner's permit, a provisional (or intermediate) license, and a full license. A learner's permit allows driving only while supervised by a fully licensed driver. A provisional license allows unsupervised driving under certain restrictions. These usually include limits on driving at night or with teenage passengers. The learner's permit and the provisional license each must be held for a specified minimum period of time.
GDL serves two functions: reducing risk and reducing exposure. GDL allows beginning drivers to acquire driving experience in less-risky situations, under direct supervision during the learner's permit phase. It helps young drivers avoid dangerous conditions such as late-night driving or driving with teenage passengers in the vehicle during the provisional phase. GDL delays full licensure by requiring a minimum time in both the learner's permit and provisional phases. Compared to earlier requirements in many jurisdictions, where beginning drivers could receive a full license at age 16 (and sometimes earlier) by passing a minimal driving test, GDL reduces the amount of driving by 16-year-old drivers. GDL also assures that young drivers are more mature when they receive their first unrestricted license.
Most States now have some form of GDL in place. NCUTLO (2000) provides a model GDL law. IIHS and TIRF (2004) summarize and discuss GDL provisions and document GDL laws in each State as of August 2004. The papers in the Journal of Safety Research special issue of January 2003 document GDL's history, components, effectiveness, parental roles, potential enhancements, and research needs. See Hedlund et al. (2003) for a summary and links to other papers, and Hedlund and Compton (2004, 2005) for updates.
Use: 40 States and the District of Columbia had a three-phase GDL system as of August 2004 (IIHS and TIRF, 2005).
Effectiveness: GDL's effectiveness in reducing crashes has been documented repeatedly (Hartling et al., 2004; Hedlund and Compton, 2005; Shope and Molnar, 2003; Simpson, 2003).
Costs: GDL's primary costs result from the provisional license, which adds to licensing agency workload by requiring each beginning driver to receive three licenses in succession rather than two.
Time to implement: Licensing changes typically require more than a year to plan, publicize, and implement.