Recent research on safe roads and infrastructure

Safe roads and infrastructure are key factors in the likelihood and severity outcome of road crashes. Although the vast majority of crashes are as a result of some form of human error, or of human error in combination with the road and/or the vehicle, we also know that the greatest determinant of crash severity will be the infrastructure that is provided. As an example, Stigson et al. [1] reviewed fatal crashes based on in-depth crash investigation, with crashes categorised based on factors that contributed to the crash outcome (as opposed to crash causation). Their study found that there were strong interactions between the different pillars of the 'system' (road user, road and vehicle), but also that the road and roadside were the most strongly linked to fatal crash outcomes. Further evidence for the importance of infrastructure comes from evaluations of safety treatment effectiveness. Individual infrastructure treatments, or treatments used in combination can significantly reduce death and serious injury. The most recent BITRE evaluation of the federal blackspot funding program showed that benefits from targeted infrastructure treatments outweighed the costs by a factor of 8 to 1 [2]. As an example, well-designed roundabouts are able to virtually eliminate deaths at intersections (by up to 80% [2]). When joined with benefits from other Safe System pillars (including vehicle improvements, speed management and improvement in road user behaviour) the combined benefits will be greatest.