What is SCATS?

SCATS are an advanced computer system that monitors in real-time the traffic signals and the volumes of traffic using them in order to use this data to coordinate adjacent traffic signals to ease traffic congestion and improve traffic flow.

SCATS are an acronym for Sydney Co-ordinated Adaptive Traffic System. It was first developed by the New South Wales Roads and Traffic Authority and is now recognised as one of the most advanced urban traffic control systems in the world.

The system is used in more than 50 cities around the world including most capital cities in Australia, Singapore, Kuala Lumpur, Jakarta, Manila, Shanghai, Hong Kong, Teheran, Qatar, Mexico City, Detroit, Minneapolis, Dublin and Auckland.

SCATS are making life a lot easier for millions of road users every day.


How Does SCATS Improve Traffic Flow?

Adaptability is the key.  The SCATS system automatically adapts to changing traffic conditions every moment of the day or night. In so doing, it is able to respond quickly to changes in traffic volume, traffic movement demands and direction of travel thereby providing the best possible traffic signal control within its area of influence.  For instance, SCATS can clear higher traffic volumes generated by sporting events far quicker than if the traffic control signals were operating independently. Its ability to coordinate traffic signals optimising traffic flow on major routes is invaluable during peak periods.

The system continually adjusts the time available to each individual traffic signal movement and by providing coordination between consecutive sets of traffic lights traffic congestion is significantly reduced. 

This does not mean that road users have a green signal at every signalised intersection as there are, after all, other road users travelling in different directions.  However, where SCATS is in operation, road users can be assured that their journey will be quicker, safer, with fewer stops and consequently more enjoyable.

When entering a main road from a side street you may be stopped at the next set of traffic lights. However as you continue along the main road your stops will be less frequent if you drive according to the current conditions and speed limits.


How Does the SCATS System Work?

The SCATS system operates on three levels:

1. Traffic Signal Controller Box

Blue-grey metal boxes located on the road verge near traffic lights contain the electronics and hardware that operate the traffic signals and are known as traffic signal controllers.  Sensors installed in the traffic lanes register traffic demand and traffic flow information.  They are connected to the traffic signal controllers, which process and relay this data to regional computers.

2. Regional Computers

There are 12 regional computers, housed in secure structures strategically located throughout the metropolitan area.  A regional computer can process data for up to 128 separate intersections simultaneously.  Each regional computer combines the on-road information with pre-programmed data, which results in optimum traffic signal operation and coordination requirements for its signalised intersections.

3. Central Monitoring Computer

The regional computers are linked to a central monitoring computer located at the Traffic Operations Centre.  This computer controls the overall SCATS system.  It enables trained operators to monitor traffic conditions and make adjustments to improve traffic flow or if necessary override the automatic system to provide manual control.


What are the benefits?

SCATS are a real time control system that optimises traffic flows on the road network 24 hours per day.  The benefits to road users, public transport and commercial freight operations are include:

  • A reduction in overall travel times;
  • A reduction in vehicle stops;
  • Reduced fuel consumption; and
  • Reduced waiting times at red traffic signals.

Combined with these benefits, are the far wider benefits to the community that good traffic management provides.  Road networks operating efficiently produce:

  • A reduction in the frequency and severity of road crashes;
  • Lower overall vehicle emissions;
  • Increased handling capacity of roads within the SCATS network;
  • Increased road safety through the early identification of equipment faults; and
  • Improved traffic signal maintenance.


Report a Fault

You can also help to prevent delays by reporting traffic signal faults, crashes and hazards:

  • Call us on 138 138 24 hours per day
  • Or complete an online form.


Modified: 04 Jun 2020