Addressing Head-on Conflicts Towards a Safe System Alignment

Head-on crashes are a serious issue in Australia and New Zealand. Head-on crashes result in significantly higher trauma than most other crash types. The provision of an appropriate median or centreline treatment is important to mitigate the risk of head-on crashes. In this webinar, Dr Rod Troutbeck, Jade Hogan and Jamie Robertson described the range of improvements from supportive treatments like pavement markings and audio-tactile line markings through to the use of flexible barriers in narrow medians as a primary treatment. The discussion and guidance centre on rural two-lane roads but also applicable to all roads. The recommended practices are based on both literature and case studies. The presenters introduced the crash modification factors developed for the hierarchy of approaches to address head-on crashes and the case studies that support these factors. The optimum solution is to provide a median barrier, however other treatments may be appropriate in certain circumstances depending on considerations including road function, space or resource constraints, and access requirements. The designer should start with the option that has the greatest Safe System alignment. It will need to be demonstrated that this option is not feasible before investigating and selecting an option with lower Safe System alignment are prioritised and other alternatives must be given lower emphasis. The presenters discussed the implications for road designers including the treatment’s applicability, effectiveness and dimensions. The maintenance considerations and implications for other road users, including sight distance requirements were also discussed.