We install, manage and maintain traffic signals, commonly known as traffic lights.
You can report a problem with a traffic signal by calling the Traffic Signals Fault Line on 1300 139 933 or by emailing firstname.lastname@example.org.
If you are reporting a traffic signal fault that is causing a safety hazard, you must call our fault line. The fault line operates 24 hours a day, every day of the year. People are available at any time to fix safety issues.
The email address is only monitored during normal business hours, 9:00 am – 5:00 pm Monday – Friday.
When reporting a fault or concern it will help us fix the issue quickly if you can tell us:
We use the Sydney Coordinated Adaptive Traffic System (SCATS) to:
Many of the traffic signals throughout the state are connected to a central system which registers and logs faults as they occur.
We monitor these logs and organise the repair works.
There are many signals around the state that are not monitored by the central system. We rely on information from the public to find out about faults at these sites. Once we know about an issue, we will attend to it quickly.
If you would like a new set of traffic signals installed on a State road, you can send your request through to us at email@example.com.
If you would like a new set of traffic signals on a Council road, you should send your request through to the relevant council.
Find out which roads are State roads on the State road network map
The main reasons to have traffic signals are:
A standard set of traffic signals consists of:
The traffic signal controller is a computer controlled device that processes information received from the detector loops and pedestrian push buttons. It changes the lights based on its programming.
The controller sets how long the light is green for each traffic movement, and controls the change from one combination of lights (known as a phase) to the next.
It can operate in a 'standalone' way, or it can be programmed to coordinate with a series of nearby traffic signals.
Vehicle loop detectors and pedestrian push buttons make the controllers 'see' them, and change the signal to give them right of way.
Vehicle loop detectors are loops of wire that work as a metal detector, buried in the road near the stop line at the intersection. When a vehicle is passing over the loop the magnetic field (inductance) of the loop changes. The controller is told that a vehicle is waiting to go through the intersection.
When the pedestrian push button is pressed the controller knows that a pedestrian is waiting to cross.
Traffic signal lights are how the controller directs traffic. They tell the road users when to go and when to stop.
Tasmanian traffic signal lanterns follow universal traffic signal colour conventions.
Each combination of green, yellow and red lights is called a phase. Each phase has a programmed minimum time. Once the signals have entered a phase they can’t change again until the minimum time has ended.
One full sequence of all the vehicle and pedestrian movements (phases) at an intersection is known as the signal cycle. The cycle time varies by location and time of day.
Traffic lights change from green to yellow to warn people that the signal is about to turn red.
The length of the yellow light depends on the speed limit of the road.
The yellow light means stop if it is safe to do so. Any vehicle travelling at the speed limit toward a green signal that changes to yellow should have enough time to stop safely. If the driver has entered the intersection, they should have time to leave the intersection before the signal changes to red.
The all-red time is the time between the end of the yellow light on one phase and the start of the green light on the next phase.
All-red time provides a safe clearance for people that cross the stop line towards the end of the yellow light, as they may be in danger of colliding with vehicles or pedestrians starting in the following phase.
The all-red time is based upon the physical size of the intersections and speed limit of the road. Similar to the length of the yellow light, the all-red time does not change throughout the day.
When the green man (‘WALK’ signal) is displayed, pedestrians can begin to cross the road with care
The flashing red man (‘DON’T WALK’ signal) means pedestrians who have already begun crossing during the green ‘WALK’ signal can finish crossing.
Pedestrians must not begin crossing when the red man is flashing.
The steady red man (‘DON’T WALK’ signal) means pedestrians should not begin crossing. Instead, pedestrians should press the button and wait for the green WALK signal.
The traffic signals at each intersection can be programmed to work in an isolated mode or be coordinated with traffic signals at nearby intersections to let traffic move along the road in ‘platoons’.
In isolated mode, traffic light changes are caused by the vehicle loop detectors and pedestrian push buttons at the intersection. This mode works very well for intersections without much traffic, if there’s no major flow of traffic in one direction, or on intersections that are a long way from each other.
The other mode is 'coordinated'. For traffic signals to be coordinated they need two things:
The benefit of coordinating signals is that large volumes of traffic can pass through multiple intersections with short delays.
The disadvantage is that because the common cycle time is set to meet the needs of the largest and most complex intersection in a series, lights at smaller intersections in the series can appear to change too slowly.
When coordinating traffic signals, the Department works hard to strike a balance between allowing the progress of vehicles along the main road and keeping the wait times for side street vehicles to a minimum.
The following link on the Queensland Department of Transport and Main Roads website explains how signals can be coordinated. It also provides an insight into the complexities and challenges in coordinating signals, especially across a number of intersections.
The Department is also responsible for the control and maintenance of electronic school zone speed signs. However, the operating times for each school zone are nominated by the relevant school to reflect the peak periods of activity.
Attribution Statement: The content in this FAQ has been adapted from the Traffic Signals Information page on the website of the Queensland Department of Transport and Main Roads. The original content is available at http://www.tmr.qld.gov.au/Travel-and-transport/Road-and-traffic-info/Traffic-Signals-Information. Licensed under Creative Commons Attribution 3.0 Australia.