Technology takes control of traffic

By Leon Engelbrecht, ITWeb senior writer

Johannesburg, 13 Feb 2007

i-Traffic, the SA National Road Agency's (Sanral's) multimillion-rand traffic management system, is being rolled out along the Western Bypass around Johannesburg, says Alex van Niekerk, Sanral manager for tolls and traffic.

Sanral already has 65 cameras in place along the N1 motorway between John Vorster Road in Centurion and Buccleuch interchange in Johannesburg as part of a R51 million project.

Sanral has access to a further 23 cameras along the M1 from Corlett to Empire Roads, although these cameras belong to the Johannesburg Roads Agency.

"It's all about making it [traffic flow] better for the public," Van Niekerk says.

The camera system and associated other road sensors, such as induction loops, will by end-2008 ring Johannesburg and its approaches. It should include the entire national road complex, such as the N12 to Daveyton, the N3 Eastern Bypass, the N17 to Alberton, the N4 around Pretoria and N1 Eastern bypass in Centurion.

The network may in time also expand to cover the R21 and R24 provincial roads that are the responsibility of the Gauteng government.

"The biggest change the public will see in coming months is a travel time update," Van Niekerk says. This will update every five minutes and indicate the latest known travel time from one site to a point indicated on the screen.

Van Niekerk adds this will tell motorists how long they can expect to commute that stretch of road. Four trial sites have been identified: near the John Vorster onramp, direction south, at Olifantsfontein, both north and south, and at Buccleuch, direction north.

Ramp meter pilot

Sanral intends to install ramp metering on some onramps to aid in decongestion on the freeway.

A ramp meter is akin to a traffic light and uses a stop-start mechanism to break up traffic flow onto the motorway. In that way it seeks to keep traffic on the highway flowing - but sometimes at the cost of backup on the feeder roads. Van Niekerk says the system will be piloted on the New Road and Samrand onramps.

Another improvement will be live video feeds of accidents to the emergency services.

"For us it is important that there is validated information going out, especially to the emergency services, [as] there are a lot of false reports on [public] radio," Van Niekerk says. "At the moment, when they receive a call, they send out certain vehicles according to a protocol, not knowing if the incident really occurred or how serious it really is."

This often means they send out an ambulance when it is not needed or when there was only a bumper-bashing, he says.