The impact of the 2007 graduated driver licensing law in Massachusetts on the rate of citations and licensing in teenage drivers.

OBJECTIVE: We recently demonstrated that the 2007 Massachusetts Graduated Driving Licensing (GDL) law decreased the rate of motor vehicle crashes in teenage drivers. To better understand this decrease, we sought to examine the law's impact on the issuance of driving licenses and traffic citations to teenage drivers.

METHODS: Citation and license data were obtained from the Massachusetts Department of Transportation. Census data were obtained from the Census Data Center. Two study periods were defined: pre-GDL (2002-2006) and post-GDL (2007-2012). Two populations were defined: the study population (aged 16-17) and the control population (aged 25-29). The rates of licenses per population were compared pre- vs. post-GDL for the study group. The numbers of total, state, and local citations per population were compared pre- vs. post-GDL for both populations. A sensitivity analysis was performed for the rates of citations using licenses issued as a denominator.

RESULTS: While licenses per population obtained by the study group decreased over the entire period, there was no change in the rate of decrease per year pre- vs. post-GDL (2.0% vs. 1.4%; p=0.6392). In the study population, total, state, and local citations decreased post-GDL (17.8% vs. 8.1%, p<0.0001; 3.7% vs. 2.2%, p<0.0001; 14.1% vs. 5.8%, p<0.0001, respectively). In the control group, total and state citations did not change (26.7% vs. 23.9%, p=0.3606; 9.2% vs. 10.2%, p=0.3404, respectively), and local citations decreased (17.5% vs. 13.7%, p=0.0389). The rates of decrease per year for total, state, and local citations were significantly greater in the study population compared with control (p<0.0001, p=0.0002, p<0.0001, respectively).

CONCLUSIONS: The 2007 GDL law in Massachusetts was associated with fewer traffic citations without a change in the rate of licenses issued to teenagers. These findings suggest that 2007 GDL may be improving driving habits as opposed to motivating teenagers to delay the issuing of licenses.