In Australia, there has been a paradigm shift to a Safe System approach that recognises that road users are fallible and will make errors, and that system design should take into account the force that a human body can tolerate before injury occurs. The Safe System approach compels system designers to pro-actively provide an intrinsically safe environment, representing a shift away from the traditional approach placing responsibility for safety on the road user. Within the road system, there are compliant road users who may make an error that leads to a crash, resulting in a ‘system failure’, and there are also road users who deliberately take risks and display dangerous or ‘extreme’ behaviours that lead to a crash. Crashes resulting from system failures can be addressed through improvements to the road system more readily than crashes resulting from extreme behaviours. The classification of crash causation in terms of system failures or extreme behaviour can assist in determining the extent to which a Safe System approach (i.e. improvements to road system design to serve compliant road users) is capable of reducing road crash numbers. There is a belief in the community that road fatalities and serious injuries are the result of risk taking or extreme behaviour and these crashes can receive extensive media coverage. In 2011 the Centre for Automotive Safety Research (CASR) examined the contribution of system failures and extreme behaviour in the causation of fatal and non-fatal South Australian crashes. The study found that very few non-fatal crashes involved extreme behaviour and even in fatal crashes, the majority were the result of system failures. However, the sample of fatal crashes was confined to data for one calendar year (2008). This current study includes data from Coroner’s files for the calendar year 2009, substantially increasing the sample size of fatal crashes. This study examined the relative contribution of system failures and extreme behaviour in South Australian crashes as identified from information in Coroner’s investigation files (2008-2009) for 189 fatal crashes. The results were compared with data from CASR’s in-depth crash investigations for 272 non-fatal metropolitan injury crashes and 181 non-fatal rural crashes. For each crash investigators determined whether extreme behaviour contributed to the crash according to a specific definition. The definition of extreme behaviour specified high levels of alcohol and speeding but some crashes involved lower levels of these behaviours that contributed to the crash (i.e. the road user was not 100% compliant or safe) and were not classified as extreme. In such cases, crashes involving any illegal behaviour that contributed to the crash or to injuries sustained during the crash were identified and formed a separate category ‘illegal system failures’. A summary of the results from the analysis of fatal crashes and non-fatal injury crashes in South Australia is given. This study shows that over half of all fatal crashes and over 90% of non-fatal crashes in South Australia involve people making ordinary road user errors or ‘system failures’. Fatal crashes resulting from system failures were more likely than those resulting from extreme behaviour to occur during the day, on weekdays, in rural areas and on roads with high speed limits. Findings from this study suggest that improvements to the road system (i.e. forgiving road infrastructure, appropriate speed limits, and safe vehicle design) can assist in reducing the incidence and severity of a large proportion of crashes in South Australia. (Author/publisher)
Abstract