Multi-lane roundabouts are generally viewed by experienced cyclists as a reasonably hazardous element of the road network to be avoided if convenient. Reviewing literature, analysing crash statistics in Auckland and surveying cyclists all confirmed the original focus of this research instigated in 2003, which was to design a low speed multi-lane roundabout for on-road cyclists. This should substantially reduce the critical ‘entering vehicle versus circulating cyclist’ crash type, and we expect it will also address roundabout exits, which is the other main safety issue concern for cyclists. The design of a roundabout that reduces unimpeded car speeds to 30 kilometres per hour requires a confined geometry. The outcome of the research project is the C-roundabout, which requires an unconventionally narrow roundabout entry that requires larger vehicles to straddle both entry lanes. A preliminary design guide for its application is included in the report. Another identified alternative is the use of vertical deflection devices on roundabout approaches. (Author/publisher)
Abstract