Risk factors associated with injury severity in crashes involving young New Zealand drivers

Young people are a menace to themselves and other road users, as motor vehicle crashes are the leading cause of their death. Understanding the factors affecting injury severity in crashes involving young drivers is useful for designing well-targeted restrictive, educational or other measures within youth-oriented safety programs for the reduction of crash severity. This study explores the underlying factors associated with the severity of crashes involving young drivers, with particular emphasis on young drivers’ risky behavior. The analysis was conducted by means of a generalized ordered logit model on a comprehensive set of single-vehicle and two-vehicle crashes that involved at least one 15-24 year-old driver in New Zealand between 2002 and 2011 and resulted in minor, serious or fatal injuries. Results show that the young drivers’ risky behavior, the presence of passengers and the involvement of vulnerable road users are the three main contributors to crash severity in both single-vehicle and two-vehicle crashes. Speeding, reckless driving and intoxication are the deadliest factors in single-vehicle crashes, while fatigue and reckless driving are the deadliest factors in two-vehicle crashes. The presence of passengers in the young drivers’ vehicle, and in particular of young males or a group of young males and females, dramatically increases the probability of serious and fatal injuries. The involvement of vulnerable road users, and in particular of motorcyclists, considerably augments the probability of higher crash severity