Making roundabouts a safe system solution for motorcyclists
Motorcyclists are very vulnerable road users. In Victoria, riders account for 15% of deaths and serious injuries. Over 30% of motorcycle crashes occur at intersections (VicRoads Road Crash Information System (RCIS)).
Roundabouts are considered a ‘Safe System solution’ for intersections because they constrain speeds and impact angles to within biomechanically tolerable levels. VicRoads Safer Roads Infrastructure Program Guidelines (2012) estimate that a roundabout will reduce overall casualty crashes by 85%.
Although roundabouts are a positive road safety treatment for motorcyclists they do not show as dramatic a reduction in road trauma as they do for cars. Scully et al. (2006) and Schoon and van Minnen (1993) estimate that roundabouts only reduce causality crashes for motorcyclists by between 36% and 77%. Between 2008 and 2012, there were 159 motorcyclists killed and seriously injured at roundabouts in Victoria. This represents 25% of all serious and fatal crashes at roundabouts (RCIS).
This paper reviews roundabout design, maintenance and operation that may influence motorcycle safety. This includes turbo-roundabouts. It also reports the results of an in-depth engineering investigation of some roundabouts in Victoria where motorcycle crashes have occurred.
Factors identified and discussed include; geometric design, sight distance, lighting, pavement markings, signing, landscaping, street furniture, speed limits and surface issues. This paper begins the work requested in the 2013 Austroads report Improving the Performance of Safe System Infrastructure wherein it states:
“Despite the positive [road safety] results, the two-wheeler risks at roundabouts need to be further reduced in order to reach the Safe System objectives.”