Author
Abstract
<p><b>BACKGROUND: </b>New Jersey (NJ) implemented the first Graduated Driver Licensing (GDL) decal provision in the U.S. in May 2010. An initial study reported a 1-year post-decal decrease in the crash rate among NJ intermediate drivers aged &lt;21 years. Longer-term analysis is critical for policymakers in other states considering whether to implement a decal provision.</p>

<p><b>PURPOSE: </b>To evaluate the longer-term (2-year) effect of NJ's decal provision on overall and age-specific crash rates of young drivers with intermediate licenses.</p>

<p><b>METHODS: </b>Monthly per-driver police-reported crash rates during January 2006-June 2012 were estimated. Specific crash types included injury, midnight-4:59am, single-vehicle, multiple-vehicle, and peer passenger crashes. Negative binomial modeling compared pre- versus post-decal crash rates, adjusting for age, gender, calendar month, gas price, and 21- to 24-year-old licensed driver crash rates; piecewise negative binomial regression models accounted for pre-decal crash trends among intermediate drivers. Analyses were conducted in 2013.</p>

<p><b>RESULTS: </b>The adjusted crash rate for intermediate drivers was 9.5% lower in the 2-year post-decal period than the 4-year pre-decal period (95% CI=0.88, 0.93). Crash rates decreased 1.8% per year before the provision and 7.9% per year in the post-decal period (p&lt;0.001 for difference in slopes). For several crash types, effects appeared to be particularly strong for 18- and 19-year-olds. An estimated 3,197 intermediate drivers had crashes prevented.</p>

<p><b>CONCLUSIONS: </b>NJ's decal provision was associated with a sustained decline in intermediate driver crashes. Future research should aim to better understand the causal mechanism by which NJ's decal provision may have exerted an effect.</p>
Year of Publication
2015
Journal
Am J Prev Med
Volume
48
Issue
2
Number of Pages
121-7
Date Published
2015 Feb
ISSN Number
1873-2607
DOI
10.1016/j.amepre.2014.08.024
Alternate Journal
Am J Prev Med
PMID
25376478