A case study on raised intersection platform on urban arterial unsignalised intersection, South Australia

With growing safety concerns for cyclists and pedestrians at metropolitan intersections the Department of Planning, Transport and Infrastructure, South Australia, has committed to trial raised intersection platform as a part of a demonstration project. The objective was to reduce the chance of occurrence of vehicles side impacting (right angle and right turn crashes) cyclists or pedestrians at intersections and also to reduce the severity outcomes in the event of crashes occurring. Raised platform force motorists to slow down when approaching and exiting the intersection. The trial was implemented at only location is the first of its kind on an arterial road in South Australia at the un-signalised intersection of The Parade West and Rundle Street in Kent Town. This study involved before and after comparison of data collected such as speed, traffic, and casualty crashes at treated sites after the platform was installed. There was not much time lapse after treatment, therefore casualty crash rates and crash types by road users group were compared to quantify the safety benefit. This study also involved an observation survey at the site and analysing complaints registered in the department after treatment to see if any unusual events are occurring or likely to occur in future. Speed data analysis shows that the trial was successful in decreasing the speed of the traffic approaching intersection. On average, mean speed decreased from 37.2 km/h to 26.6 km/h and the 85th percentile speed decreased from 47.9 km/h to 34.0 km/h. Likewise, no serious injury crashes between vehicle-cyclist were reported since its installation as compared to two crashes during before period. The project was successful to reduce the approaching speed limit on the intersection close to the survivable speed of 30km/h; outcomes of this study could be replicated at intersections where cyclist or pedestrian movements are high and their safety is critical.