Assessment of the effectiveness of on-road bicycle lanes at roundabouts in Australia and New Zealand

This report documents the research undertaken for Austroads on bicycle lanes at roundabouts. An extensive literature review informed empirical data gathering .The literature review revealed strong evidence that bicycle lanes on the approach and within roundabouts are associated with negative safety outcomes. Limited and inconclusive research was found on high-speed, multi-lane roundabouts. The dominant cyclist injury crash type involved a motorist entering a roundabout failing to give way to a circulating cyclist. Cyclists could maximise their safety by tracking closer towards the inscribed island. Cyclist lateral tracking was observed at urban roundabouts, which showed that they commonly travelled close to the centre of the traffic lane. Where bicycle lanes were present in the circulating carriageway, they were rarely used by riders. When lane markings were changed at roundabouts to encourage lane sharing, this significantly shifted cyclist positions. It was concluded that the presence of bicycle lanes within the roundabout may serve to discourage lane sharing. High-speed, multi-lane roundabouts were not studied due to the unacceptable risk the researchers would have been exposed to. A key conclusion from the research is that new or modified roundabouts would ideally either have equitable speeds, or provide for cyclists so that they donrt have to enter the circulating carriageway. All the evidence is pointing towards speed being the major road safety issue at roundabouts. If the underlying fundamental problem is addressed, then the question that this research is supposed to answer (will bicycle lanes at roundabouts improve safety?) will become secondary. Our research shows conclusively that cyclists maximise their safety when they occupy a lane, and this is most easily achieved when speeds are equitable.