Center for Injury Research and Prevention

Policy Petri Dish – New Jersey Decal Study Resonates

March 1, 2013
Learn more about NJ’s decal provision in an upcoming free Webinar, as part of a series run by the Network for Public Health Law, on Thursday, March 21 at 1 p.m. (EST).

This week, we were excited to learn that our article “Graduated Driver Licensing (GDL) Decal Law: Effect on Young Probationary Drivers” has been selected RWJF's No. 1 Most Influential Research Article of 2012.

The Robert Wood Johnson Foundation mission is bold and broad: “improving both the health of everyone in America and their health care—how it's delivered, how it's paid for, and how well it does for patients and their families.” How did a study on a single provision of one state’s GDL program grab the attention of health care policy stakeholders?

I asked Allison Curry, PhD, MPH, lead author and director of epidemiology at CIRP@CHOP, about why she thought the study resonated so strongly with the broader public health community. She gave much credit to the state of New Jersey, saying: “The state’s unique policy environment presented the field of health policy research with a rare opportunity to evaluate the effect of a specific requirement intended to increase public safety.”

What Makes New Jersey Special for Research?

Beginning in May 2010, New Jersey became the only state in the US requiring teen drivers to display an identifier, referred to as a “decal,” on the outside of their vehicles. The purpose of the decal is to enhance law enforcement's ability to enforce life-saving restrictions placed on newly-licensed drivers.

Identifiers have been used for decades in other countries but there has never been an opportunity to study its independent effects before because the requirement was usually implemented in a package of new GDL provisions. Due to the quirks of the legislative process, NJ’s decal was enacted as a single new provision with only slight modifications to other existing provisions.

Like New Jersey, these other countries relied solely on a strong theoretical model to defend and enact a decal requirement, rather than evidence of effect. So, globally, other countries are looking to NJ’s experience to confirm that their decals are sound policy. Nationally, states are contemplating whether decals might help them reduce teen driver crash rates. All eyes are on NJ.

Dr Curry also emphasized that the rigor of this study would not have been possible without NJ’s foresight to develop databases that could be merged and analyzed.  The state collects quality data in two different databases: the Licensing and Registration Database and the Crash Record Database, both maintained by different state agencies.

Remarkable cross-agency cooperation allowed Dr. Curry and her co-authors to merge the databases together to analyze rates in police-reported crashes and citations according to status of the license holders. The authors then isolated de-identified records of drivers with probationary licenses to observe the effect of the new requirement on their crashes and citations. More states ought to replicate this!

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