Driver's License and Crash Patterns for Young Drivers

Previous nationally representative surveys have described important reasons why young drivers delay getting a drivers license but have been unable to estimate population-level licensure rates and trends. In a series of three research projects, Allison E. Curry, PhD, MPH and her team looked at drivers license and crash patterns in New Jersey for young drivers. Findings indicate that age and experience matter when it comes to young driver crash rates and support extending age requirements for the intermediate phase of Graduated Driver Licensing (GDL) to 21 years.

Research Projects

Young Driver Licensing in New Jersey, Rates and Trends: 2006-2011

Using the New Jersey Motor Vehicle Commission's Licensing and Registration Database, researchers analyzed population-based rates of licensure among youth ages 17 to 20 years (n=255,833) overall and by key socioeconomic factors. This analysis also looked at trends in licensure from 2006 to 2011.

While virtually all 18- to 20-year-old New Jersey residents in the highest income areas are licensed by age 21, more than one in three residents in the lowest income areas are not licensed by age 21.  40% of all residents in New Jersey – and half of those eventually licensed by age 21 – obtain a drivers license in the first month they are eligible, but this looks very different for zip codes by income:

  • Among those living in the lowest income zip codes, only 13% are licensed within one month of turning 17, and only 36% are licensed by age 18.
  • 65% of those living in NJ's highest income zip codes are licensed immediately upon turning 17, and 78% are licensed within six months.
  • A look at licensing trends by zip code-level race/ethnicity found that 92% of teens in zip codes with the highest proportion of non-Hispanic white residents were licensed by age 18 compared with 39% in zip codes with the lowest proportion of this group.
  • A look at licensing trends by zip code-level race/ethnicity found that 92% of teens in zip codes with the highest proportion of non-Hispanic white residents were licensed by age 18 compared with 39% in zip codes with the lowest proportion of this group.

In NJ, the rates and timing of licensure have remained stable since 2006 despite changes to the state's GDL provisions and the economic recession, indicating that this is not a recession-driven trend. Also stable is the median age of licensure among those licensed by age 21: 17 years 1 month. From 2006 to 2011, 8,257 to 8,653 17- to 20-year-olds were issued driver licenses each year.

Read the full report

Principal Investigator: Allison Curry, PhD, MPH
 

Funding: AAA Foundation for Traffic Safety

Young Driver Crash Rates in NJ by Driving Experience, Age, and License Phase

A second report examined the independent and joint contributions of age at licensure, driving experience, and GDL license phase on 24-month crash rates among the population of NJ drivers who were first licensed from age 17 through age 20. Crash rates by age of licensure, driving experience (based on time since licensure) and GDL licensure phase were calculated to determine crash risk. The results indicate that in NJ, age and experience matter when it comes to young driver crash rates.

Where full GDL applies to all novice drivers under age 21, crash rates among teens licensed at age 18 are 33% lower after 12 months of driving as compared to their crash rates after one month of driving. Relative to adult drivers, crash rates among NJ's 17- and 18-year-old drivers decreased significantly after the state implemented its GDL system in 2001.

Read the full report

Read a blog post about the research

Principal Investigator: Allison Curry, PhD, MPH

Funding: AAA Foundation for Traffic Safety

Older Novice Driver Crashes in NJ--Informing the Need for Extending GDL Restrictions

A third report evaluated whether there is epidemiological evidence to support -- from a crash risk perspective -- adoption of passenger and nighttime restrictions for older novice drivers (ages 21 and older). Researchers utilized the New Jersey Traffic Safety Outcomes Data Warehouse to select all NJ drivers who were licensed between 2006 and 2014 and then grouped them on their age when licensed: 17; 18 to 20; 21 to 24; and 25 or older to study overall crash rates, as well as early and late night crashes and multiple passenger crashes.

Crash rates for young novice drivers are highest during early night (9 pm to 11 pm) and decline rapidly over the course of licensure. However, late night (11 pm to 4:59 am) crash rates are higher among drivers licensed at age 18 to 20 than those licensed at age 17. Study findings support NJ’s GDL policies for 17- to 20-year-old novice drivers and the potential for added benefits from beginning the nighttime restriction at 9 pm instead of 11 pm. There was a lack of compelling evidence to extend GDL restrictions for newly licensed drivers ages 21 to 24. There is no evidence to indicate a need to extend GDL policies to newly licensed drivers ages 25 and older.

More research is needed to study crash risk beyond age when licensed to help explain differences in long-term crash risk for young novice drivers.

Read the full report

Read a blog post about the research

Principal Investigator: Allison Curry, PhD, MPH

Funding: AAA Foundation for Traffic Safety