The road safety debate is full of misinformed opinions - after all, everyone's an expert. And those who have beliefs a long way from the facts can be found on both side of the debate - from "I am a safer driver than all those old farts on the road" through to "All young drivers should have a 80 km/h speed limit". In this series we'll bring you the facts on young drivers. Are young drivers more likely to have crashes than other road users? And if so, why? What is the influence of a lack of driving experience; does the common "it won't happen to me" sentiment lead to the adoption of risky driving practices? Should drivers have much more extensive training before being allowed unrestricted licenses?
The Problem
"Young drivers have twice the death rate compared to people of all ages" |
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Young drivers represent a significant road safety problem. Deaths due to transportation-related crashes are higher in the 15-to-24 age group than any other age group, with twice the death rate compared to people of all ages. In New South Wales, 1994 statistics show that young drivers accounted for 31 percent of all road injury deaths in males and 19 percent in females. Similarly, 1995/96 figures show that the rate of hospitalisations for road injury were around twice as high for 15 to 24 year olds as for all ages.
These figures indicate that young drivers are at high risk of injury and death due to crashes on the road.
But why? What are the factors responsible for this?
1. Exposure Factors
- Amount of Time on the Road
The road is a hazardous environment, so simply being on the road is of importance in crashes occurring for any road user. Data on crash risk as a function of the distance travelled shows that accident rates (eg per million kilometres travelled) are higher for younger drivers than for older drivers. This suggests that young drivers who are on the road the most are more likely to crash. Conversely, a lack of on-road driving time is also thought to be a risk factor for crashes, since the opportunity for gaining driving experience is limited.
So on the one hand, evidence shows that young drivers who spend more time on the road are more likely to have crashes, yet young drivers with little experience are also more likely to have crashes. These findings signal that the relationship between the amount of time on the road and injury risk is not a simple one. Too little exposure increases crash risk, but so does very high exposure. The problem seems to be one of finding the right balance between obtaining on-road experience and managing the nature of that exposure.
For young drivers, crash statistics from a number of studies demonstrate that they are more likely to involve single-vehicle crashes. One study attempted to establish the reasons for higher risk for single-vehicle crashes in young drivers compared to the crash-risk for older drivers, but found no relationship with any of these factors: drunk driving, speeding, fatigue, illness, type of vehicle, road conditions or even lack of a license. Factors that were related to higher risk for young drivers were poor vehicle condition and less time spent on the road. Australian research demonstrated that young drivers were also more likely to crash on curves and slopes and to crash due to loss of control of the vehicle. Again, the reasons for young driver crashes, especially involving single vehicle crashes, seem to be complex and need further investigation.
Time of the day and week has also been demonstrated to be an important risk factor for young drivers. Most crashes occurred over the weekend period, and in the late afternoon and night period. This pattern is also seen for older drivers, but young drivers show a disproportionately higher risk compared to older drivers at these times. This indicates that time factors should be interpreted as one of the additional risk factors for young driver crashes.
The role of environmental factors has been less well established as a specific risk factor for young drivers. Crashes for young drivers are more likely to occur on country roads, but this is also so for older drivers. Around six times more crashes involving young people also occur in fine weather compared to weather involving rain, fog, mist and snow. However this most probably reflects the result of exposure, since in Australia we tend to have considerably more fine days than days with poor weather. Unless the crash rates for bad weather days were much higher than for good weather days, it would be unlikely to show up in the statistics as the days when young drivers are on the road are more likely to be fine. More work is needed to establish whether the crash rates due to environmental factors like the weather are higher for young drivers.
2. Social and Situational Factors
"Accident risk increases when young drivers carry passengers" |
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There is evidence that the social setting in which young drivers operate plays a role in determining driver behaviour. The major factors that have been identified as important are: the presence and type of passengers, the influence of peers and the social group, and the role of alcohol.
A consistent finding between studies is that accident risk increases both day and night when young drivers carry passengers, whereas older drivers show no difference in crash rates with and without passengers. Interestingly, the type of passengers seems to be important, in particular when the passengers are teenagers and when there is more than one passenger. The presence of passengers has been shown to influence driving behaviour for both young males and females, through less signalling behaviour and changes in speed. The evidence suggests that the type of passenger is important since the effects on increasing speed were shown in the presence of friends or when travelling alone, but not when parents were present. [Not a surprise! - Ed]
The idea that young drivers are more susceptible to peer and social influences has been put forward by a number of authors to explain the young drivers' higher crash risk and to explain the influence of young passengers on crash risk. By this argument, the influence of peers can prompt greater risk taking since the young driver feels that they must conform to the standards and style of behaviour advocated by their peer group.
Alcohol use has been well-documented to be a risk factor for crashes in young drivers and is cited as one of the major risk factors in many reports on the young driver problem. There is evidence, however, from some studies that young drivers involved in crashes are likely to have lower or zero blood alcohol levels (BAC) than older drivers involved in crashes. The main reason for the emphasis on alcohol as a risk factor is that there is considerable evidence that alcohol is a risk factor for crashes because it adversely affects driving style.
3. Young Driver Factors
"The youngest group of drivers has the highest road injury risk" |
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One of the most consistent findings in the literature on young drivers is that the youngest group of drivers has the highest road injury risk. For example, a recent report on age-related crash risk in Western Australia demonstrated that crash risk was between 60 to 70 percent higher for the youngest driver age group (17 to 19 year olds) compared to the next oldest group (20 to 24 year olds)! These differences persisted when the distances driven were taken into account. There is some evidence that the youngest drivers have crashes for different reasons. For example, a US comparison of crashes involving 16 year olds showed that, when compared with other fatal crashes, young drivers were more likely to crash due to their own error and far less likely to crash due to alcohol-effected driving. But accident risk varies considerably within the young driver group, with younger drivers showing the highest risk of all.
Crash statistics show all too clearly that, compared to females, males are significantly over-represented in road crashes. Death rates for road injury in NSW are around three times higher for males than females and have been that way for the last decade or more. Young males - as either driver or passenger - have fatality rates around three times higher than for females.
The major behaviour factors seen as relevant are sensation seeking, aggressiveness and egocentrism. Sensation seeking has been linked with risk-taking behaviour which is often cited as a characteristic of young drivers that explains their higher crash risk. Sensation seeking has been linked to a range of different behaviours including driving practices such as speeding and drink-driving. Aggressiveness has also been linked with risky driving on the premise that risky driving can be an expression of anger and hostility. Research shows that young people with higher aggression tend to drive more recklessly. Egocentrism has also been linked to young driver crashes. According to this concept, adolescents tend to underestimate their vulnerability to risk ("it won't happen to me").
A recent Australian study defined five subtypes among young novice drivers. Two of these subtypes were classified as high risk compared to the others. These high-risk subtypes were characterised by higher driving-related aggression, speed, sensation seeking, using driving to reduce tension, higher assaultiveness and hostility. The differences between subtypes were validated in a study of performance in a driving simulator. The high risk subtypes showed inferior driving skill compared to the other three subtypes.
There is recent evidence of a link between hyperactivity, attention deficit hyperactivity disorder (ADHD) and road injury risk. Studies in the USA and New Zealand, for example, demonstrated that young drivers with hyperactivity or ADHD problems are more likely to exhibit poor driving behaviour - especially speeding - and show a higher injury risk.
Next week: Changing young drivers.
This series comprises an edited version of a December, 1999 paper prepared by:
Ann Williamson, PhD
NSW Injury Risk Management Research Centre
University of New South Wales
http://www.irmrc.unsw.edu.au
The work was funded by the Motor Accidents Authority of NSW as part of their activity in the area of young driver safety.
The full version of the paper is available at: http://www.irmrc.unsw.edu.au/papers/drivers.pdf It includes extensive referencing of sources.
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