Paper presented at the 23rd Annual Southern African Transport Conference 12 - 15 July 2004 "Getting recognition for the importance of transport", CSIR International Convention Centre, Pretoria, South Africa. The paper describes the background, modelling, geometric design and performance of the
reconfigured Armitage Road/Sanctuary Road interchange on the N3 in Pietermaritzburg.
This reconfigured interchange is the first rotary type constructed on a National Route in
The development of the node surrounding the original half-diamond interchange (including a
regional shopping centre), rendered the existing interchange incapable of handling the
projected traffic volumes. The new interchange needed to satisfy both commuting and access
requirements. Furthermore, the constrictions imposed by the site and financial constraints
dictated that the options in meeting the stated goals were limited. In order to accommodate
these divergent functions, innovative proposals were tested in the quest to provide an efficient
and effective solution. The modeling and testing was undertaken using a combination of
accepted computer programs namely SIDRA and the SimTraffic/Synchro pairing. The
adopted rotary interchange was deemed the optimum in complying with the various
constraints. This assessment process is described in detail in the paper.
The rotary design parameters are dealt with covering, particularly, the geometry, the
constraints and scope, roadmarking and signposting.
The rotary was commissioned one week before the opening of the regional shopping centre
that serves the entire KwaZulu-Natal Midlands. Consequently the rotary was subjected to
intense testing in a very short period of time by motorists who themselves were undergoing a
The performance in the weeks and months following the commissioning is explained in the
paper covering the adjustments and fine-tuning necessary to achieve optimum performance
This paper was transferred from the original CD ROM created for this conference. The material on the CD ROM was published using Adobe Acrobat technology. The original CD ROM was produced by Document Transformation Technologies Postal Address: PO Box 560 Irene 0062 South Africa. Tel.: +27 12 667 2074 Fax: +27 12 667 2766 E-mail: firstname.lastname@example.org URL: http://www.doctech.co.za