• November 4th, 2019

Graduated Driver Licensing (GDL) systems were designed to protect young novice drivers by creating a safe environment in which to learn to drive and limit exposure to known high-risk conditions until the drivers have amassed at least several months of experience driving. A large body of research has found that GDL systems have substantially reduced the rates of crashes, injuries, and deaths of 16- and 17-year-old drivers. However, AAA Foundation research has estimated that as many as one in three drivers do not obtain their first license until the age of 18 or older. Although previous AAA Foundation research has also shown that that new drivers licensed at ages 18-20 have crash rates similar to equally-inexperienced younger beginners and much higher crash rates than same-aged peers with more driving experience, most states do not apply most key provisions of their GDL programs to new drivers aged 18 years or older.

On July 1, 2015, the state of Indiana modified its Graduated Driver Licensing (GDL) system, extending restrictions on driving late at night and on carrying young passengers—previously only applicable to newly-licensed drivers younger than 18—to all newly-licensed drivers under the age of 21. Specifically, the updated GDL program restricted new drivers under age 21, from driving between the hours of 10 p.m. and 5 a.m. and from carrying non-family passengers for their first six months of license driving, unless they had a qualifying supervisor (a licensed driver aged 25+, or 21+ if the supervising driver is the driver’s spouse). This study examines the crash rates of drivers who received their first driver’s license at ages 18-20 in the state of Indiana before versus after Indiana updated its GDL system.