Southern Expressway Traffic Management System

One of the key functions of the Traffic Control Centre (TCC) is the management of the reversible Southern Expressway which was built to alleviate the pressure, particularly during peak hour, on the existing Main South Road.

This carriageway is a unique concept in road design. Traffic travels in only one direction at a time, with changeover occurring twice a day.

To keep vehicles moving at a reasonable pace, the Southern Expressway has:

• a speed limit of 100 km an hour
• a minimum of two lanes with an emergency stopping lane
• no signaled intersections allowing a non-stop journey on the Expressway.

State of the art traffic monitoring equipment allows

• Traffic Control Centre operators to view the road to ensure that the roadway is completely clear before reversing the direction of traffic flow
• motorists to clearly understand the direction and condition of the Expressway.

The operators use computer and video technology to monitor and control the flow of traffic

• electronic overhead signs at the approaches to the entry and exit points indicate the direction of traffic with crosses and arrows
• red lights on the side of the road warn motorists attempting to travel in the opposite direction to the flow of traffic
• roadside signs along the Southern Expressway flash in hazardous situations
  • yellow to advise motorists to slow down
  • red to stop
• video cameras on a line of high towers scan the road’s 20 kilometre length to check for any problems or vehicle breakdowns
• emergency phones every 500m are directly linked to Traffic Control Centre operators who call for assistance and arrange for towing.

If a breakdown occurs when the traffic flow is about to change, tow trucks under contract to Transport SA will tow the vehicle to our depot for collection. Motorists are requested to use the roadside phones to call for assistance and remain with their car until help arrives.

Traffic flow direction times