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
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
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
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%.