Crash involvement among unlicensed 17 year old drivers before and after licensing at 17 was allowed

Unlicensed driving among youth is associated with increased crash risk, and partly motivated by a wish to learn to drive. In this paper we examine whether crash involvement among 17-year-old unlicensed drivers changed after post-licence accompanied driving from the age of 17 was allowed in Denmark in 2017. The study includes police-registered crashes occurring three years before and three years after the change (2014-2019). Results show an increase in crash involvement among 17-year-olds and a small increase in crash involvement among unlicensed 17-year-olds, if population size is taken into account, but no differences in the crash and person characteristics before and after the change. Being male, speeding, and impairment at the time of the crash predicted unlicensed crash involvement. A latent class clustering analysis (LCCA) identified seven clusters of crashes involving an unlicensed 17-year-old. The cluster characteristics reveal different patterns in the associated factors such as females and parked vehicles being more likely to be included in C1, alcohol impaired in C2 and drug impaired in C7. Brief crash descriptions provided by the police indicate that driving with extra motives such as showing-off or pleasure are prevalent in all clusters. Results confirm, that unlicensed crash involvement among 17-year olds is associated with risk-taking behaviours such as speeding, impaired driving, showing-off, and the car being pursued by the police. However, unfortunate manoeuvres and loss of control of the vehicle possibly related to poor driving skills are also associated with the crashes. Crash characteristics such as impairment by alcohol and drugs indicate that unlicensed crash involvement is a distinct safety challenge associated with health risk behaviours rather than a transport related need for a driver's license. Additional studies exploring the motivations and circumstances associated with unlicensed driving among 17-year olds are needed along with measures to prevent car access among unlicensed youth..