Science Headlines – Dangerous driving

An information service for media in New Zealand

For more information you may contact any of the following scientists directly, or email headlinescience@rsnz.org or call 04 4705758.

24 July 2007

This past weekend saw seven people die on New Zealand roads. Scientists comment here on our high road toll, accident rates for inexperienced drivers, and how young people overrate their driving skills.

1. Associate Professor Shanthi Ameratunga is Director of the Traffic-Related Injury in the Pacific (TRIP) Project funded by the Wellcome Trust and Health Research Council of New Zealand. She is a paediatrician, public health physician and injury epidemiologist, based at the School of Population Health, University of Auckland.

“Last year, New Zealand’s road toll was 387. This is an improvement on the carnage on our roads a decade or two ago, but a far cry from the much lower rates of road deaths in Australia - particularly the State of Victoria, the UK and Scandinavian countries.

“A third of those killed are aged between 15 and 24. Among our men, more potential years of productive life are lost from road crashes than from any other cause. And for every road death, there are 50 to 100 “survivors” who live with physical and emotional scars. Research we undertook in Auckland showed that the long-term impact on quality of life is substantial.

“At a global level, road deaths amount to a “9/11” every 18 hours. Over 90% of these deaths occur in the low- and middle-income countries, and most of those killed are vulnerable road users such as pedestrians, cyclists and motorcyclists. The burden is enormous and escalating – especially in rapidly motorizing countries like India, China, and many parts of Africa.

“At the School of Population Health, we are undertaking an international collaborative project with partners at the Fiji School of Medicine, and government and non-government agencies in Fiji, Samoa and Palau to better understand the context, causes and opportunities to prevent injuries. A goal of the Traffic-Related Injury in the Pacific (TRIP) Project is to identify priorities for road safety policy and intervention. The preliminary information from this project is already pointing to the vital importance of the 4 E’s: education, engineering, environment and enforcement. Too often and to our cost, we consider just the first and stop short of rigorously evaluating what works and what does not. In the Pacific as well as New Zealand, hard calls are required if we want to aspire to safer drivers, safer vehicles and safer roads.”

2. Ben Lewis Evans is a Human Factors Scientist in the Transport Research and Evaluation section at the Ministry of Transport
Phone: (04) 439 9063
Email: b.lewisevans@transport.govt.nz

"We've been looking at the Graduated Driver Licensing System - taking the license register and cross-referencing with the Crash Analysis System, the database that holds information about all crashes in New Zealand.

"The learner phase is relatively safe, but there's a marked increase in accidents as soon as the driver progresses to the restricted phase. In fact, there's a 5 to 7-fold increase in crashes as drivers move from the last month of their learner license to the first month of their restricted license. They're inexperienced, but they're driving more and they're driving solo. During the first 6 months, the crash involvement reduces dramatically, and continues to reduce at a slower rate for some time.

"If a driver is older, say 18, when they get their restricted licence, the risk is still there but it's significantly reduced.

"Another huge risk factor for drivers is alcohol. If a 30+ year old is driving at the legal limit of 80mg of alcohol per 100ml of blood, they are 16.5 times more likely to have a fatal crash than they would when they're sober. The risk is much bigger for younger drivers: a 15-19 year old with the exact same blood alcohol level is 86.6 times more likely to have a fatal crash than a sober 30+ year old. The legal limit for 15-19 year olds is 30mg of alcohol per 100ml of blood, but even at this level they are still up to 15 times more likely to have a fatal crash compared to a sober 30+ year old."

3. Dr Niki Harre is community psychologist at The University of Auckland
Phone: (09) 3737599 ext. 88512
Email: n.harre@auckland.ac.nz

“I’m interested in self enhancement bias – drivers’ general tendency to overrate their driving skills. That bias is particularly prominent in young people. My colleague, Susan Foster and I did some research with young people in New Zealand technical institutes in which 73 percent of young men said they were more skilled at driving than their peers. Most of the rest said they were as skilled as their peers, so there’s a very small percentage who admit to being less skilled. The young women in the study, which was published in the British Journal of Psychology in 2005, were much less likely than men to think they had better driving skills than others.

“The problem of course is that the perception that you’re more skilled may lead you into risky driving behaviour. For example, if you look at people with disabilities who may have slower reflexes than other drivers, you find that they don’t have more crashes than others. People tend to drive to their skill level. So perceiving yourself as more skilled leads you to be happier with riskier conditions such as driving night, in wet conditions or going fast down the motorway.

“Now my colleague Dr Chris Sibley and I are looking into more detail about why this self enhancement bias exists. For young men in particular, it seems that being a skilled driver is a part of your identity, is a way of establishing yourself with your peers, and probably has a lot of sexual connotations as well. We’re going to look more directly into why, when people take risks on the road, they don’t necessarily think they are doing so.”

Science Headlines is a service managed by the Royal Society of New Zealand and funded by the Ministry of Research, Science and Technology.

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