Evaluation of New Jersey’s Graduated Driver Licensing System

The Problem/Background

• Cars crashes are the number one killer of teenagers in the United States – 5,881 U.S. highschool-age teens died as occupants in traffic crashes in 2006 and 2007.
• The Graduated Driver Licensing (GDL) movement in the U.S. began in 1996. Today, all U.S. states contain at least some elements of a GDL program; however, there is substantial variation in the comprehensiveness of state GDL programs.
• New Jersey is the only U.S. state in which a new driver must be 17 years old to obtain a license that allows driving without an adult in the vehicle. New Jersey’s GDL system, effective January 1, 2001, applies to all new drivers irrespective of age and is widely
  regarded as one of the more comprehensive state GDL programs. GDL provisions in effect in New Jersey during the study period included:
  • Permit – Minimum age 16, supervised driving with adult, nighttime and passenger restrictions, practice for 6 months
  • Restricted license – Minimum age 17, unsupervised driving (except 12am-5am), passenger restrictions, practice for 1 year
  • Unrestricted license- Minimum age 18, no other restrictions

The Study

• Compared crash rates of teenage drivers before and after the implementation of GDL in New Jersey
• Crash rates of teens were compared to those of adults to take into account overall trends unrelated to GDL.
• Analyzed data on fatal crashes in New Jersey from the National Highway Traffic Safety Administration (1995–2007), and data on all police-reported crashes in New Jersey from the New Jersey Department of Transportation (1998–2005).

Findings

• Substantial reductions in the all police-reported crashes (16%), crashes resulting in injuries (14%), and fatal crashes of 17-year-olds (25%) in New Jersey after implementation of GDL, in relation to the crash rates of adults who would not have been directly affected by GDL.
• Overall police-reported crashes and injury crashes of 18-year-olds decreased by 10%, and fatal crashes by 4%.
• Effects were especially large after midnight, when holders of provisional licenses are restricted from driving. Nighttime crashes of 17-year-olds decreased by 40%, and those of 18-year-olds decreased by 17%, in the years after GDL implementation.
• In the years before New Jersey enacted its GDL program (1995-2000), New Jersey ranked 45th out of 51 jurisdictions in its population-based fatal crash involvement rate of 17-year olds in relation to adults. Several years after GDL enactment (2004-2007) its ranking improved to 21st.