University of North Carolina Highway Safety Research Center, 730 Martin Luther King, Jr Blvd, Suite 300/Campus Box 3430, Chapel Hill, NC 27599-3430, United States.
Accid Anal Prev. 2010 Nov;42(6):1647-52. doi: 10.1016/j.aap.2010.04.002. Epub 2010 Apr 28.
Several studies document the success of graduated driver licensing (GDL) systems in reducing young teen crash rates, but it is not yet clear whether any portion of the crash reduction is achieved by producing more capable drivers. The purpose of this study was to determine whether young teen drivers licensed under the North Carolina GDL system remain crash-free longer than those licensed prior to GDL, independent of the crude reductions in exposure (i.e., decreasing and delaying licensure) that may be responsible for most documented effects of GDL. Survival analysis was used to compare retrospective cohorts of 16-17 year olds before (n=105,569) and after (n=327,054) the North Carolina GDL system was implemented. The crash incidence of GDL-licensed 16-17 year olds (combined) was 10% lower than that for pre-GDL teens for at least 5 years after being licensed to drive independently (hazard ratio [HR]=0.90; 95% confidence interval [CI]=0.89, 0.91). However, more refined analysis revealed the reductions to only be among females (7%; HR=0.93; CI=0.91, 0.94) and males (15%; HR=0.85, CI=0.84, 0.87) licensed at age 16 and not among females (0%; HR=1.00; CI=0.95, 1.06) and males (0%; HR=1.00; CI=0.92, 1.09) licensed at age 17. Sixteen-year-old drivers licensed under the North Carolina GDL system experienced lower first-crash incidence during the first 5 years of unsupervised driving than did those licensed under the previous system. The benefits are greater for males, who tend to have higher crash rates. The findings contradict conventional wisdom that the entire benefit of GDL results merely from decreasing or delaying licensure among young drivers.
多项研究证明，驾考分级制度（Graduated Driver Licensing，GDL）可有效降低青少年事故率，但目前尚不清楚这一制度是否能培养出更优秀的驾驶员，从而降低事故率。本研究旨在明确北卡罗来纳州 GDL 系统下获得驾照的青少年在独立驾驶后的头五年内，是否比 GDL 实施前获得驾照的青少年更不易发生事故，从而确定其驾驶技能是否有所提升。本研究采用生存分析法比较了 GDL 实施前后（北卡罗来纳州，n=105569）16-17 岁青少年的回顾性队列。结果显示，GDL 驾照持有者的事故发生率比 GDL 实施前的青少年低 10%，至少在独立驾驶后的 5 年内（风险比[HR]=0.90；95%置信区间[CI]=0.89，0.91）。但进一步分析发现，事故率降低仅发生在 16 岁获得驾照的女性（7%；HR=0.93；CI=0.91，0.94）和男性（15%；HR=0.85，CI=0.84，0.87）中，而 17 岁获得驾照的女性（0%；HR=1.00；CI=0.95，1.06）和男性（0%；HR=1.00；CI=0.92，1.09）中则没有降低。在未受监督的驾驶的头 5 年内，北卡罗来纳州 GDL 系统下获得驾照的 16 岁驾驶员首次发生事故的几率较低。对于男性而言，GDL 系统的好处更大，因为他们的事故率往往更高。这些发现与传统观点相矛盾，传统观点认为 GDL 的全部好处仅源于减少或推迟年轻驾驶员的许可。
