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Effectiveness: 5 Star Cost: $
Use: High
Time: Medium

GDL is a three-phase system for beginning drivers, consisting of a learner’s permit, an intermediate license, and a full license. A learner’s permit allows driving only while supervised by a fully licensed driver. An intermediate 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 intermediate 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 and 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 intermediate phase. GDL delays full licensure by requiring a minimum time in both the learner’s permit and intermediate phases. Compared to earlier requirements in many jurisdictions, where beginning drivers could receive a full license at 16 (and sometimes earlier) by passing a minimal driving test, GDL reduces the amount of unsupervised driving by 16-year-olds. GDL also ensures that young drivers are more mature when they receive their first unrestricted license. Based on a national survey, the majority of parents (61 to 98% depending on the policy) support GDL policies that are as strong as, or even stronger, than policies currently in place in the United States (Williams et al., 2011).

All States now have some form of GDL in place. However, as of September 2020, no State GDL systems met all the qualification criteria set forth by the Fixing America’s Surface Transportation (FAST) Act for GDL incentive grants. For example, some States have night restrictions beginning later than 10 p.m., or allow teens to carry more than one passenger younger than 21. GHSA (2019a) and IIHS (2019b) document GDL laws in each State. These websites are updated monthly. The papers in the special issue of the 2007 Journal of Safety Research describe GDL’s history, components, effectiveness, parental roles, potential enhancements, and research needs. Strategies for implementing or improving GDL systems are described in NCHRP’s Guide for Reducing Collisions Involving Young Drivers (Goodwin et al., 2007, strategies A1 through A5). See also NHTSA’s Traffic Safety Facts on GDL (NHTSA, 2008) and Report to Congress (Compton & Ellison-Potter, 2008), and the Traffic Injury Research Foundation’s New GDL Framework: Evidence Base to Integrate Novice Driver Strategies (Mayhew et al., 2014).

Use: All States and the District of Columbia had some GDL components in place as of May 2019. In addition, all States and the District of Columbia had a three-phase GDL system in place (GHSA, 2019a; IIHS, 2019b).

Effectiveness: GDL’s effectiveness in reducing young driver crashes and fatalities has been well-documented (Baker, Chen, & Li, 2007; Chapman et al., 2014; Chaudhary et al., 2018; Fell et al., 2011; Lyon et al., 2012; Masten et al., 2011, 2013, and 2015; McCartt et al., 2010; Russell et al., 2011; Shope, 2007; Simpson, 2003; Williams, 2017). The most restrictive GDL programs–those with at least a 6-month holding period during the learner stage, a night restriction beginning no later than 10 p.m., and restrictions allowing no more than one teen passenger–are associated with a 38% reduction in fatal crashes and a 40% reduction in injury crashes among 16-year-old drivers (Baker et al., 2007). In addition to reducing crashes, GDL is associated with declines in hospitalization rates and charges for 16-year-old drivers (Margolis et al., 2007; Pressley et al., 2009). A review of Georgia’s GDL laws 15.5 years after implementation suggests that positive outcomes continue to be seen over time (Thompson et al., 2016). Fatal crash rates of young drivers 16 to 19 who participated in the State’s GDL system were examined over 21 years (5.5 years prior to and 15.5 years after GDL law implementation). Overall, the fatal crash rates stayed similar to the pre-implementation rates, but they did decrease for certain groups of young drivers. The highest rates of decline were among male drivers who were 16 and 17 years old. The greatest changes in the rate of decline between pre- and post-law implementation were for alcohol- and speeding-related crashes, which are two of the three risky behaviors targeted by the State’s GDL laws.

Costs: GDL’s primary costs result from the intermediate license, which adds to licensing agency workload by requiring each beginning driver to receive three licenses in succession rather than two. These costs are typically covered by small fees charged by the licensing agency.

Time to implement: Licensing changes typically require up to a year to plan, publicize, and implement.

Other issues:

  • Age of licensure: Over the years, there has been discussion about the most appropriate age for allowing teenagers to drive independently (Foss et al., 2014; Williams, 2009; Williams et al., 2013). Licensing ages vary from State to State, from a low of 14½ in South Dakota to a high of 17 in New Jersey. Delaying licensure, either through higher entry ages or GDL requirements such as extended learner stages, can reduce young driver crashes (Foss et al., 2014). For example, New Jersey’s GDL system has eliminated most crashes among 16-year-old drivers and has reduced crashes among 17-year-olds by 16% (Williams et al., 2010). However, a national study found a significant increase in fatal crash rates among 18-year-olds associated with stronger GDL components (Masten et al., 2011). Similar increases in overall crash rates have been found in drivers 18 and older (Conner & Smith, 2017; Curry, Metzger, et al., 2017; Thompson et al., 2016). (But see Foss et al. [2014] for an exception: drivers licensed at 18 were more likely than drivers licensed at any other age to be involved in injury crashes in the first year post-licensure). These findings indicate that there might be value in extending GDL provisions for drivers 20 and younger; one study found a lack of evidence for extension of provisions beyond 21 years old (Curry, Metzger, et al., 2017). In addition, licensure rates have decreased among young teenagers (HLDI, 2013; Shults & Williams, 2013). Thus, there is concern that teens may be delaying licensure until they are 18 or older in order to avoid GDL provisions, leading them to miss out on the safety benefits of GDL. However, based on findings from additional studies, it appears the economic recession and lack of employment for young teenagers has been the driving force behind the delay of licensure and not avoidance of GDL (HLDI, 2013; Tefft et al., 2013a; Williams, 2011).