Strengthening Driver Licensing Systems for Teenaged Drivers

Abstract

GRADUATED DRIVER LICENSING PROGRAMS ARE designed to reduce crashes involving teenagers by delaying full licensure while allowing beginners to obtain initial driving experience under lower-risk conditions. Graduated driver licensing strengthens the traditional learner phase by adding elements such as certification of a minimum number of practice driving hours and a minimum learner’s permit holding period. It also adds an intermediate license between the learner phase and full licensure that restricts unsupervised driving in risky situations (eg, driving at night and transporting teenaged passengers). Although Florida is credited with having enacted the first graduated driver licensing program in the United States in 1996, the benefits of delaying licensure and restricting nighttime driving were demonstrated in the 1980s and early 1990s. Currently, all states and the District of Columbia have enacted some form of graduated driver licensing. As states adopted graduated driver licensing, per capita rates of fatal crashes among teenaged drivers decreased substantially. Between 1996 and 2009, there were large declines inthesecrashrates for15-year-olds(69%),16-year-olds(68%), and 17-year-olds (53%) (the ages directly affected by graduated driver licensing) and smaller but substantial declines for 18-year-olds(43%)and19-year-olds(39%). Thesedecreases in rates of fatal crashes were greater than declines among 30to59-year-olddrivers (33%during thisperiod).However, in 2008 the rate of police-reported crashes per mile driven for 16to 19-year-olds was 4 times the rate for older drivers, and their rate of fatal crashes was twice that for older drivers. In jurisdictions that have adopted elements of graduated driver licensing, overall crash rates among young teenagers have declined by 20% to 40%. Restrictions on nighttime driving and transporting teenaged passengers have proven effective in reducing relevant crashes. National studies have found that 3-stage graduated driver licensing programs (with learner’s, intermediate, and full licensure stages) and laws that impose more licensing components, or more restrictive components, are associated with decreases in per capita rates of fatal crashes or fatalities among young teenagers. The study by Masten and colleagues in this issue of JAMA adds new evidence on this important topic and reports a 26% lower per capita rate of fatal crash incidence for 16-yearolds associated with stronger graduated driver licensing programs. Masten et al also report a 12% higher rate of fatal crash incidence for 18-year-olds and a nonsignificant, slightly lower rate for 16to 19-year-olds combined. Implementation of the 3-stage concept of graduated driver licensing has differed among states, and licensing practices vary widely. The Insurance Institute for Highway Safety (IIHS) evaluated the strength of state licensing systems, rating them as good, fair, marginal, or poor. Criteria include the strength of the learner and intermediate phases (entry age and duration for both phases, a practice driving requirement in the learner phase, and strength of restrictions on nighttime driving and allowable passengers in the intermediate stage). The learner’s permit and licensing ages are not inherent to a staged-in approach to licensure but are fundamental aspects of licensing laws and may be affected by graduated driver licensing provisions. Therefore, a comprehensive approach is needed to understand fully how licensing laws affect safety. The findings reported by Masten et al differ from those reported in 2 other studies using the IIHS ratings to measure the strength of licensing laws. McCartt et al evaluated the association between stronger licensing laws and teenagers’ per capita rates of fatal crashes. That study found a strong association between better IIHS ratings and lower rates of fatal crashes among 15to 17-year-olds. Associations between the IIHS ratings and rates of fatal crashes for 18and 19-year-olds were weaker and generally not statistically significant. Compared with laws rated poor by the IIHS, those rated marginal, fair, or good were associated with a significantly lower rate of fatal crashes for 15to 19-year-olds combined, including a 16% lower rate for laws rated good. In another report, Trempel evaluated the association between stronger licensing laws and the rates of insurance collision claims per insured vehicle year; only licensed drivers are insured, and collision claims primarily involve lowseverity crashes. There was a strong association between better IIHS ratings and lower collision claim rates among 16