Innovative NTCIP Lane Control System…
The South African National Roads Agency (SANRAL) has a significant ITS roll out program underway in Johannesburg, South Africa. This roll out is motivated both by increasing traffic that has resulted from the booming economy, but also the need to improve the traffic infrastructure in time for the Soccer World Cup, to be hosted by South Africa, in 2010. The initial deployment of cameras, electronic signs, traffic sensors, traffic management center and a fiber optic communications network has been focused on the freeway linking the major cities of Johannesburg and Pretoria. This highly congested stretch of road is the busiest stretch of roadway in the African continent, and the South African road authorities, with their consultants and contractors, have deployed a number of innovative technologies to help manage congestion.
![[Traffic]](http://www.intelligentdevicesinc.com/eNewsletters/images/SATraffic.jpg)
Intelligent Devices have provided the central control software (the Intelligent Control suite) as well as other products and services. Of interest to US ITS deployment officials will be the significant contribution that NTCIP has made to the success of the deployment. DMS signs, traffic sensors, the pilot ramp meter controllers, all field communications, database structures and inter-process communications (e.g. to the travel time algorithm) have all been based on the NTCIP data dictionary standards… but this is the topic for a future article.
One of the problems on this freeway, is two areas of “bottleneck congestion”, one north and one south bound. These bottlenecks are caused by excessive traffic between two consecutive interchanges, where the demand greatly exceeds the roadway capacity. Adding additional lanes will take years… and so an alternative solution was implemented.
The hard shoulders in the “bottle neck” congestion area were repainted to provide an additional travel lane, and appropriate electronic and static signage placed to allow the hard shoulder to be opened in times of congestion
A set of rules were established for the supervisors in the TMC. The lane may be opened if (1) congestion would occur if it were not opened, and (2) it is safe to do so. So how are these criteria evaluated? Three factors are used in the evaluation of congestion: (a) the visual observation of the traffic through the camera system (b) the supervisors experience in managing the roadway at that time of day (c) the data from the road sensors, which are displayed on real time graphs, with threshold alarms, in Intelligent Control ![[Graph]](http://www.intelligentdevicesinc.com/eNewsletters/images/SVGraph.jpg)
(Speeds are in kilometers – in case you think they drive too fast in South Africa).
The second criteria (safety) is based on the freeway being free of incidents. The current incident table is displayed in Intelligent Incident, for the operators to keep appraised of the status of current incidents.
Finally, the status of the Lane Control System and the adjacent Dynamic Message Signs is displayed on the wall display by Intelligent Control, so everyone can see the current status of this part of the system.
![[Signs]](http://www.intelligentdevicesinc.com/eNewsletters/images/LCSSigns.jpg)
What has been interesting to see has been the short integration duration, and aggressive roll out schedule, that has been accomplished on this ITS system, enabled in part by these extensive and successful use of NTCIP. The successful roll out of this system has been accomplished in less than six months since first operator training, which is a fantastic achievement. Complements to everyone involved! |
