Adelaide Coordinated Traffic Signal (ACTS) System

The Adelaide Coordinated Traffic Signal (ACTS) system is an advanced computer system responsible for the smooth flow of traffic through more than 580 sets of coordinated traffic lights throughout the metropolitan region.

One of the most sophisticated urban traffic control systems in the world, ACTS is a dynamic system which continually measures traffic at intersections and adjusts the time available for each movement to give you the safest, quickest and least frustrating trip through the network.

By coordinating traffic lights to ease congestion and improve traffic flow, ACTS helps to make travelling smoother and quicker for all users

• light sequences, lane directions and turn arrows can all be manipulated to improve traffic flow
• immediate response is made to peak hour build-ups, accidents and other traffic problems
  • pedestrians are given the time they need to cross the road safely at pedestrian crossings
  • cyclists waiting at intersections are included in the signal phasing when they use ‘cyclist push buttons’ (located near bicycle lanes)
  • bus passengers are given priority through the use of white ‘B’ lights.

The Traffic Control Centre monitors ACTS 24 hours a day, automatically responding to changing traffic demands.

The advanced computer system works at three levels.

• Local controllers (the large grey metal boxes near traffic lights) collect traffic flow information from detectors embedded in the road just behind the white ‘stop’ line at intersections.
• Regional computers then receive this information and determine when to display the green light and when to switch to yellow.
• The central computer located in the Traffic Control Centre links all the regional computers, enabling staff to monitor and adjust the operation of traffic lights in all the regions.

The information captured by Adelaide Coordinated Traffic Signal (ACTS) system

• activates an immediate response to daily traffic conditions
• provides valuable trend data
  • to guide planning of enhancements or changes to the existing road environment
  • for developing new traffic solutions.

How you can make the most of the system

• Stop just behind the white ‘stop’ line - you won’t be detected if you are more than four metres away
• Stop on yellow lights (if it is safe to do so) so you will be ahead of the next coordinated traffic stream and have fewer stops
• Travel at the speed limit - ACTS is designed to coordinate traffic travelling at normal speeds
• Wait in the lane with the shortest queue
• Ring 1800 018 313 to report signal faults, incidents and congested sites

Benefits to the community

The Adelaide Coordinated Traffic Signal (ACTS) system helps the community by

• reducing road crashes
• increasing road safety through early identification of signal faults and traffic problems such as blown globe
• reducing vehicle emissions and fuel consumption
• reducing traffic congestion
• increasing the traffic handling capacity of roads.

Studies have shown that compared with uncoordinated systems, ACTS

• cuts travel time by up to 20%
• reduces stops by more than 40%
• lowers fuel consumption by 12%.