How do we achieve vision zero when the safe system is managed by different entities with varying constraints

Abstract

The goal of eliminating fatal and serious injury crashes on the road network has been simplified into a two-word statement Vision Zero that carries with it, an extremely significant volume of design and construction activity to achieve the goal. The logical risk mitigation approach of elimination is that if we remove all cars, there ceases to be car crashes. In the more likely scenario that cars continue to operate, the task of eliminating fatal and serious car crashes remains. There is a limited variety of different safety treatments in the engineering ‘handbook’, and they each have a limited ability to treat the identified issue. In some cases the cause of a crash may be unable to be treated by way of engineering intervention. Similarly, engineering controls and intervention is the third most effective treatment out of the typically five step hierarchy of controls pyramid. The reality is that there are many constraints to eliminating fatal and serious injury crashes and these issues are summarised within the Vision Zero: National Road Safety Strategy. Key to this strategy is The Safe System, of which is comprised by four pillars. The road authority only has real control and the ability to manipulate the ‘safe road infrastructure’ pillar. Whilst the road authority sets the ‘safe speed’ pillar, this relies on compliance by the road user. The remaining two pillars of safe vehicles and safe road user behaviour are inherently beyond the control of the road authority. Therefore, if we presume that the road authority can achieve 100% efficacy on the pillar within their immediate grasp (ignoring the technical constraints), this leaves 75% of the pillars unmanaged. Further presume that safe speed can be managed by way of 50% efficiency (urban issues resolved, rural issues remain at large), 50% of the pillars need to be addressed. Safe vehicles as a pillar is incredibly important as the difference of in-vehicle safety features compared today to 20 years ago is significant. The difficulty with moving this pillar toward the 2050 vision is to manage the age of existing vehicles that pose a threat to safety. With or without the future prospect of driverless cars, the absence (and difficulty) of introducing legislation around the restriction of aged vehicle ownership, appears to be one pillar that will be incredibly difficult in reaching 100% efficacy without legislative intervention. The last pillar ‘safe road user behaviour’ is equally difficult – if not more so – to manage given the difficulty to predict or account for road user behaviour. The basis of the National road safety strategy (being the Safe System) actually identifies one primary flaw, being that humans make mistakes. As policy and decision makers reach a point where all pillars have been treated to reduce crash risk to as low as reasonably practical (ALARP) and ‘safe road user behaviour’ is the last pillar to be treated, it seems highly likely this may catalyse the uptake of driverless cars (and/or other new and possibly controversial technologies).