The safety of traffic circles in eThekwini

Abstract

Paper presented at the 33rd Annual Southern African Transport Conference 7-10 July 2014 "Leading Transport into the Future", CSIR International Convention Centre, Pretoria, South Africa.

National and international literature and research generally indicate that traffic circles (roundabouts) have a much better safety record than stop controlled and signalised intersections, especially when the severity of accidents are taken into account. A comprehensive investigation was done in eThekwini to evaluate the safety of traffic circles. Thirteen traffic circles were evaluated from a safety point of view, and compared to the safety record of twenty one traffic signals and ten stop controlled intersections. The intersections were chosen to cover a wide range of traffic volumes, so that accident rates could be plotted against average daily traffic for all three intersection types. Both accident rates and accident severity rates were analysed. Contrary to what is found in the literature, results showed that many traffic circles had higher accident rates and accident severity rates than traffic signals for the same average daily traffic. For higher daily traffic volumes (above 20 000 vehicles per day), traffic circles were found to have an alarmingly high accident rate compared to what is found in the literature. Possible reasons for the high accident rate at high volume circles are given, and the applicability of the research to the rest of South Africa is noted.