Turbo roundabouts as an alternative to two lane roundabouts

Abstract

Paper presented at the 26th Annual Southern African Transport Conference 9 - 12 July 2007 "The challenges of implementing policy?", CSIR International Convention Centre, Pretoria, South Africa. ABSTRACT:The turbo roundabout is an innovative arrangement of the two lane roundabout that has revolutionised roundabout design in The Netherlands since 1998. Entering and exiting the previously applied two lane roundabout can be complicated for road users, which consequently leads to road safety problems. The turbo roundabout concept eliminates some of the most severe conflict points on the roundabout. A quick-scan evaluation model indicates that the capacity of the turbo roundabout is about 25 – 35% higher than a standard two lane roundabout. The introduction of the turbo roundabout in South Africa can have a massive impact on the road safety situation in the country. The turbo roundabout is an ideal intersection solution for road accident hotspots. In addition, as South Africa is experiencing unprecedented traffic growth in the urban areas, the turbo roundabout could offer significant efficiency improvements to the transportation networks.