Association between New Jersey's Graduated Driver Licensing decal provision and crash rates of young drivers with learners' permits

New Jersey (NJ) implemented the first-in-the-US Graduated Driver Licensing (GDL) decal provision in May 2010 for young drivers with learner's permits or intermediate licenses. Previous analyses found an association between the provision and crash reduction among intermediate drivers. The aim of this study is to examine the association between NJ's provision and GDL citation and crash rates among drivers aged <21 years with learner's permits. We estimated monthly per-driver rates from January 2006 through June 2012. Negative binomial modeling compared pre and post decal crash rates adjusted for gender, age, calendar month, and gas price. The monthly GDL citation rate was two per 10 000 drivers in the predecal and postdecal periods. Crashes were rare and rates declined similarly pre and post decal (adjusted rate ratio of postdecal vs predecal slope: 1.04 (0.97 to 1.12)). NJ's GDL decal provision was not associated with a change in citation or crash rates among young NJ drivers with learner's permits.