Crash risk for young drivers is determined by several related factors [1]. The relatively high crash risk for young drivers is due to individual factors such as development of the brain, lack of higher-order skills (such as the ability to predict how traffic situations will progress), lack of driving skills and the driver’s attitude towards driving a car. In addition, temporary factors and the social environment may increase the risk.
Development of the brain
A person’s brain is only fully developed around age 25. The part of the brain that urges us to ‘to think first and act later’ is the last part to fully develop. It ensures that previous experiences are used to make decisions [4]. The part of the brain that regulates emotions, motivation, and satisfaction of needs is much quicker to fully develop [5]. Due to this asynchronous development, young drivers are more inclined to take risks, are susceptible to peer pressure and seek to satisfy their own needs such as ‘pleasure’ [6]. The capacity of our working memory, that enables us to remember items as long as they are relevant to us, also continues to develop during adolescence. The slow development of this capacity is associated with a self-reported increased crash risk [7].
Higher-order skills
Reference is often made to higher-order skills or executive functions that are still in the making due to the slow development of the brain. Thus, young drivers have trouble predicting how a traffic situation will progress, which makes them less proficient in anticipating potential dangers than more experienced drivers [8]. They also have trouble fully appreciating risks and are inclined to overestimate their skills. That is why their (risky) behaviour is not in accordance with their abilities [9]. In addition, a certain negligence towards risk makes particularly young men tolerant of higher traffic risks [10]. Due to the limited capacity of the working memory and the inability to fully control impulses, young road users are less able to process stimuli and focus their attention on relevant elements of the traffic situation, to make decisions, and plan how to behave [7].
Driving experience
Young drivers run the highest risks during the first year of driving independently (for more information, see the question How does chrash risk develop during the driving career?). They consider the acquisition of a driving licence to be proof of their driving proficiency, which was after all established by an examiner [11]. However, they still have to gain experience in applying the acquired skills in different situations during the first few years after their initial qualification [12].
Attitude towards driving and risky driving behaviour
For young drivers that really appreciate cars and love driving, or for those who really enjoy going out, crash risk is higher than average (e.g. see the Danish study by Møller and Sigurðardóttir [13]). Their friends affect the risk behaviour of young drivers. The attitude of their friends towards risky driving behaviour (the peer group standards) relates to the extent to which young drivers display risky driving behaviour (e.g. see studies in Germany [14] and Israel [15]).
Factors that temporarily reduce fitness to drive
When comparing young drivers to middle-aged drivers, the following effects of temporary factors can be noted:
- Young drivers do not drink-drive more often, but do run higher risks when drink-driving (see the question Is the use of drugs and alcohol a problem among young drivers? and SWOV fact sheet Driving under the influence of alcohol).
- Young male drivers more often drive under the influence of drugs. See the question Is the use of drugs and alcohol a problem among young drivers? and SWOV fact sheet Drugs and medicines for more information about drug use by young drivers.
- International research shows that young drivers are more often distracted by young passengers while driving [16] and by the use of audio devices and mobile phones [17], which greatly increases crash risk. For more information about this subject, see the question Is distraction a problem for young drivers?.
- For young drivers, fatigue is of more importance, because they more often drive at night, when the natural inclination to fall asleep is felt ([18]; SWOV fact sheet Fatigue). In addition, a mismatch exists between the biological development of the sleep-wake rhythm, the amount of sleep young people need and the daily rhythm imposed by school, education or work [19]. Yet, for young people fatigue caused by lack of sleep is hard to intuit and therefore also hard to control [20]. A UK study shows that lack of sleep is related to a higher crash risk [21].
- Extreme emotions may cause young drivers to display risk behaviour. The way in which emotions affect behaviour, depends on the personality of the young drivers and the context in which they find themselves [22].
Social environment
A ‘sporty driving style’ is adopted to impress friends. For young drivers with one or more young passengers, crash risk is higher than if they drive without passengers. Conversely, crash risk decreases in the presence of middle-aged passengers. The presence of young passengers increases risk more strongly for male drives than for female drivers. For young male drivers, the effect of the presence of a passenger is greater when the passenger is male than when she is female [16]. Parents set the example for their children; a parent’s driving behaviour therefore predicts the driving behaviour of young drivers [23]. Moreover, a young driver’s risk behaviour depends on the extent to which parents encourage safe behaviour and set clear boundaries [4].
Speed
International literature shows that young drivers are relatively often involved in crashes caused by not adjusting their speed to the traffic conditions [24], for example when cornering [25]. The inability to adjust speed to traffic conditions is related to several factors mentioned above, such as insufficient driving experience, trouble in balancing risk behaviour and one’s own skills and coping with peer pressure. Dutch research into self-reported speeds shows that young drivers do not exceed speed limits on motorways just after driving licence acquisition, but that this changes when they are somewhat older (aged 20-24) [8].
Environment
Young drivers relatively often drive in conditions that also increase crash and injury risk for experienced drivers: they often drive in somewhat older cars with fewer passive and active safety devices [26] and they probably drive in the dark more often.
