Roundabouts Along Rural Arterials in South Africa

The use of roundabouts in both an urban and rural context have been gaining ground over the past twenty years not only in South Africa, but also in many other parts of the world. Apart from the geometric design details and the operational characteristics of roundabouts there is also no clear guidance in terms of the spacing of roundabouts, specifically when it comes to using them along a high order road. Often the spacing requirements for signals along arterials are being used as a guideline to determine the spacing of roundabouts. This paper explores the practical use of roundabouts along arterials and specifically along high speed rural arterials with relatively high commuter traffic volumes. This is done for a rural arterial in the Western Cape, South Africa. The focus of the evaluation is specifically done in the context of operational efficiencies, access management and future capacity requirements of the arterial. The operational efficiencies of the roundabouts along the corridor, currently and under future higher demand scenarios, was evaluated using micro-simulation analysis where roundabout control is compared with traffic signal control. The comparison of the simulation results clearly highlights the operational advantages of using roundabouts, but it also illustrates possible future capacity constraints for the roundabout scenarios. Based on the simulation results it is evident that roundabouts could play a role in the rural arterial context, not only operationally but also in terms of safety and future capacity expansions.

Language

  • English

Media Info

  • Media Type: Digital/other
  • Features: Figures; Maps; Photos; References;
  • Pagination: 12p
  • Monograph Title: TRB 93rd Annual Meeting Compendium of Papers

Subject/Index Terms

Filing Info

  • Accession Number: 01506612
  • Record Type: Publication
  • Report/Paper Numbers: 14-1425
  • Files: PRP, TRIS, TRB, ATRI
  • Created Date: Feb 6 2014 4:50PM