Publication Details


Long-term effect of Graduated Driver Licensing (GDL) requirements in North Carolina

Type: Paper

Subtype: Final report

Author(s): Foss, Robert D.; Masten, Scott V.; Martell, Carol A.

Pages: 86

Publisher: UNC Highway Safety Research Center

Publication Date: Jul-2014

Address: Chapel Hill, NC

Abstract: Most U.S. states have enacted graduated driver licensing (GDL) systems to reduce death, injury and the associated costs that result from the unusually high crash rates of young novice drivers. These systems encourage beginning drivers to obtain substantial practical experience before being allowed to drive without protective restrictions that reduce their high crash propensity. GDL involves an initial learner period requiring adult supervision of a new driver. A second, intermediate licensing level allows unsupervised driving, but involves limits on driving in the most dangerous situations for novices. With but a single exception, all U.S. GDL systems include a night driving restriction and 45 also limit the number of young passengers allowed during the intermediate license period – addressing the two most clearly identified high risk driving conditions for teens (Chen et al, 2000; Tefft, Willliams & Grabowski, 2013; Ferguson, Teoh & McCartt,2007). The final tier in a graduated licensing system is a full, essentially unrestricted license. The details of GDL systems in the U.S. vary widely, but nearly all states currently have a full, 3-tier system in place, whereas almost none did in 1995. The present study was conducted to address several gaps in our knowledge of the various possible effects of GDL. Specifically, we examined (1) whether the initial effects of a GDL program endure, erode or increase after a program has been in effect for a period of time, (2) the effect of adding a passenger restriction to an established GDL program, (3) whether/how crash rates among older teen drivers change subsequent to introduction of a GDL system, and (4) whether identified effects of GDL were broadly evident across crash severity levels, time of day, time of week (weekday vs weekend), crash location (urban vs rural) and crash type (single vs multiple vehicle).