Know your network

Managing the network

It takes state-of-the-art technology and an expert team to monitor and manage the NSW road network 24 hours a day, seven days a week.

Traffic Commanders and Traffic Emergency PatrolsTraffic Emergency Patrol crew diverting traffic

Traffic Commanders and Traffic Emergency Patrols (TEPs) provide on-the-spot support for motorists by managing traffic around road incidents such as accidents and breakdowns.

There are 10 Traffic commanders patrolling Sydney roads, who take control of the traffic management arrangements around incidents to keep motorists safe and get traffic moving.

They are assisted by eight fully equipped road-based TEP crews who help maintain traffic flow by setting up traffic controls and assist in clearing incidents and repairing roads.

We also have dedicated field resources to respond to and manage incidents in regional areas of NSW.

Our dedicated team of towing staff work to clear breakdowns and incidents in key locations such as Sydney Harbour Bridge, Sydney Harbour Tunnel and ANZAC Bridge.

Tidal Flow Systems

Traffic follows a predictable pattern at different times of the day on Sydney's key roads. Tidal Flow Traffic Systems increase the number of available lanes during peak times to maximise traffic flow.

Generally, manual Tidal Flow Traffic Systems are used but there are also five automated systems in Sydney located at:

Tidal Flow Systems were first used on the Sydney Harbour Bridge in the late 1940s and fully automated systems were introduced in 1985. With more than 175,000 vehicles crossing the bridge every day, the Tidal Flow Traffic System is a critical part of its traffic management.

Traffic Monitoring Cameras

The Transport Management Centre (TMC) has a network of over 1,200 Closed-Circuit Television (CCTV) cameras monitoring traffic throughout Sydney and in key locations across NSW, linked via a computerised video control system.

The primary role of CCTV is to help the TMC manage incidents and traffic flow and to detect incidents on particularly high volume sections of the road network including:

Variable Message Signs and Variable Speed Limit SignsVariable Message Sign

Variable Message Signs (VMS) are placed at over 580 strategic locations across the NSW road network and Variable Speed Limit Signs (VSLS) are situated on major arterial roads including the M4 Motorway, M5 Motorway, M1 Pacific Motorway and General Holmes Drive.

Together with real-time communications tools, they help reduce delays, keep traffic flowing smoothly and improve driver safety, allowing speed limits to be varied based on traffic volumes, unfavourable road or weather conditions and incidents.

Detour signage

Detour routes are denoted by the use of 'D' and 'D1' signs and have been developed to be activated when an incident occurs that closes one or both road directions or causes extensive delays to motorists. Detour signage offers a route that bypasses the cause of the delays and can be seen on the M1 Pacific Motorway and M5 Motorway.

Sydney Harbour BridgeElectronic Lane Changing System on Sydney Harbour Bridge

The Sydney Harbour Bridge is used by almost 59 million vehicles each year making it one of the busiest roads in NSW.

The TMC uses a number of traffic management techniques to manage the traffic flow including the Electronic Lane Changing System (ELCS). The ELCS controls eight lanes of traffic and is managed remotely by dedicated Sydney Harbour Bridge traffic controllers.

The ELCS integrates electronic overhead signage, automatic movable medians and in-pavement lighting to adjust traffic direction, on average, five times a day in four different configurations.

Traffic lights

RMS manages over 3,200 sets of traffic lights in NSW Sydney's first traffic lights were installed at the intersection of Market and Kent streets and switched on at 11am on Friday 13 October 1933. The first audio signals for blind pedestrians installed in 1967. Now there are over 3,700 sets of traffic lights across NSW.

Real-time traffic management

Sydney Co-ordinated Adaptive Traffic System (SCATS) was developed by Roads and Maritime Services (RMS) in the 1970s to enable RMS to control and co-ordinate traffic across NSW in real-time. SCATS now manages, monitors and co-ordinates over 3,700 intersections in NSW. RMS still owns, maintains and continually improves the SCATS software for the benefit of the NSW public and many SCATS users world wide.

SCATS is able to react to changing traffic conditions in real-time by adjusting the timing and co-ordination of each traffic light cycle. Traffic flow and volume are measured at each intersection by sensors embedded in the road, after which the SCATS computers analyse this information, calculate the best possible light timings, co-ordinate intersections and adjust the signal times accordingly.

SCATS can also operate in 'isolated' mode if necessary. In this mode, the system generates an automatic alert if problems occur. Operators are able to manually override the automatic operation when required.

SCATS has been recognised internationally as one of the best adaptive traffic systems and RMS sells the software to road agencies around the world. For information on the distribution of SCATS visit

Public Transport management

Public Transport Information and Priority System (PTIPS) was developed by RMS as part of the Bus Priority Strategy. It works with SCATS to manage traffic light timings and allow buses to run as close as possible to their timetables.

GPS and radio communications provide bus location information that can be used to forecast the arrival time of a bus at traffic lights. If a bus is running late, SCATS can alter traffic signal timing at approved non critical intersections to allow the bus to maintain its scheduled timetable, giving bus passengers a more reliable service and letting bus operators schedule their buses more efficiently.

PTIPS was initially trialled on the northern beaches run in 2008 and then rolled out across the whole of the State Transit Authority (STA) bus fleet in 2009/10.

Other trials using the SCATS priority feature were then trialled on three strategic bus corridors in Sydney including:

Currently all the STA buses are deployed with PTIPS and plans are under way to deploy PTIPS on other non Government buses.

Green Light CorridorsGreen light corridor to deliver baby giraffe to Taronga Zoo

In special situations the Transport Management Centre creates a Green Light Corridor - a synchronised traffic light system that allows a vehicle to proceed uninterrupted on its journey. Such corridors are usually arranged in advance but in emergency or life threatening situations (such as organ delivery), Green Light Corridors are set up immediately. Examples of recent Green Light Corridors include VIP visits such as the APEC conference, the Pope's visit for World Youth Day and a baby giraffe delivery to Taronga Zoo.


Sea Cliff Bridge on Lawrence Hargrave Drive

Management of regional and local roads

Regional roads provide a secondary network that, together with the State roads, link smaller towns and provides routes within major urban centres that don't require the use of main roads.

The maintenance of regional roads is generally the responsibility of Local Councils with funding provided by the State Government.

Local roads are also the responsibility of Local Councils with limited funding assistance from the State Government.

Private road management

M7/M4 Light horse interchange The State Government has partnered with several private companies to build and operate a number of motorways around Sydney, the Sydney Orbital Network, which comprises over 160 kilometres of roads.

The main benefit of these motorways, most of which include a toll, is that they avoid many sets of traffic lights, providing a faster way to move around the city. They include the: