Traffic lights

We use the Sydney Coordinated Adaptive Traffic System (SCATS) to:

• coordinate traffic signals
• record faults (such as blown lights)
• record data for performance monitoring (eg. traffic counts at intersections)
• manage traffic incidents and special events

You can report a problem with a traffic signal by calling the Traffic Signals Fault Line on 1300 139 933 or by emailing traffic.signals@stategrowth.tas.gov.au.

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:

• the location of the traffic signals – the 4 digit number on the controller box, or the street names
• details of the fault/concern
• when you noticed the fault
• any other information that you consider relevant.

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, please email: traffic.systems@stategrowth.tas.gov.au

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:

• to allow road users to safely move through an intersection
• to give priority to a particular direction or mode of travel at different times of the day
• to let large amounts of traffic to pass through the network with minimal delay by coordinating signals.

A standard set of traffic signals consists of:

• a traffic signal controller
• vehicle detector loops and pedestrian push buttons
• traffic signal lights
• posts, pits and underground electrical cables that connect all the components together.

The traffic signal controller

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

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

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.

• GREEN = Go if it is safe to do so.
• YELLOW = Stop if it is safe to do so
• RED = Stop.

Signal phases and cycles 

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.

The yellow light

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.

All-red time

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 pedestrian signal is displayed, pedestrians can begin to cross the road with care

The flashing red pedestrian signal means pedestrians who have already begun crossing during the green pedestrian signal can finish crossing.

Pedestrians must not begin crossing when the red pedestrian is flashing.

The steady red pedestrian signal means pedestrians should not begin crossing. Instead, pedestrians should press the button and wait for the green pedestrian 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:

• A common signal cycle time: The signal time is the time it takes to run through one complete sequence of all the vehicle and pedestrian movements (phases) at an intersection.
• A difference in time between the start of one intersection's main green movement and the next intersections main green movement so that vehicles travelling at the designated speed limit leave the first intersection on the green signal and reach the second intersection at the same time as its signal turns green.

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.

http://www.tmr.qld.gov.au/Travel-and-transport/Road-and-traffic-info/Traffic-Signals-Information#Coordination

This means you don’t need to press the button to trigger the green pedestrian signal.

We’ve added stickers on traffic poles to let you know which crossings will change automatically.

Intersections where some or all of the crossings operate automatically are also listed below.

Remember – you must wait for the green pedestrian signal before you cross the road.

Davey Street intersections

Davey Street, at the intersections of the Southern Outlet, Barrack Street, Harrington Street, Murray Street, Elizabeth Street, Argyle Street and Campbell Street.

Macquarie Street intersections

Macquarie Street, at the intersections of the Southern Outlet, Antill Street, Barrack Street, Molle Street, Harrington Street, Murray Street, Elizabeth Street, Argyle Street, and Campbell Street.

Collins Street intersections

Collins Street, at the intersections of Barrack Street, Harrington Street, Murray Street, Elizabeth Street, Campbell Street and Argyle Street.

Liverpool Street intersections

Liverpool Street, at the intersections of Barrack Street, Harrington Street, Murray Street, Elizabeth Street, Argyle Street, Campbell Street and Tasman Highway.

Bathurst Street intersections

Bathurst Street, at the intersections of Harrington Street, Murray Street, Elizabeth Street, Campbell Street, and Argyle Street.

Melville Street intersections

Melville Street, at the intersections of Harrington Street, Murray Street and Argyle Street.

Brisbane Street intersections

Brisbane Street, at the intersections of Murray Street, Harrington Street, Argyle Street and Campbell Street.

Brooker Highway intersections

Brooker Highway, at the intersections of Burnett Street, Risdon Road, Ashbolt Crescent and Bowen Road, and Derwent Park Road.

Additional crossings

Murray Street near Centrepoint Shopping Centre

Argyle Street near the Royal Hobart Hospital

Morrison Street at the intersection of Murray Street

Elizabeth Street intersections

Elizabeth Street, at the intersection of Wellington Street, St. John Street and Charles Street.

York Street intersections

York Street, at the intersections of Bathurst Street,  Wellington Street, Charles Street, St John Street, and George Street.

Brisbane Street intersections

Brisbane Street, at the intersections of Wellington Street, Charles Street, St. John Street and George Street.

Paterson Street intersections

Paterson Street, at the intersections of Wellington Street, Charles Street, St John Street and Margaret Street.

Cameron Street intersections

Cameron Street at the intersection of St. John Street and George Street.

Frederick Street intersections

Reiby Street, at the intersection of Victoria Street.

Cattley Street, at the intersections of Mount Street and Wilson Street

Mount Street, at the intersection of Wilmot Street

Wilmot Street at the intersection of Wilson Street

North Terrace at the intersection of Mount Street

Ladbrooke Street at the intersections of  Wilson Street and Mount Street

Alexander Street, at the intersection of Cattley Street

Why aren’t all crossings automated?

When deciding whether to automate a crossing, the number one consideration is pedestrian safety.

In order to be automated, the crossings also need to have the right technology to allow them to be managed remotely. Not all locations can be managed remotely due to equipment limitations.

Some crossings with low numbers of pedestrians may also not be automatic, especially if they have a red ‘right turn’ signal.

If the pedestrian crossing is triggered at these intersections it turns on the red right-turn traffic light for the designed time, holding up all people waiting to turn. If the pedestrian crossing is automatically triggered, it may hold up traffic even when no-one is crossing the road.

Why do only certain cities have automated crossings?

In order to be automated, the crossings need to have the right technology. We have been progressively upgrading the equipment at our traffic signals.

We have been prioritising areas that have more traffic and higher numbers of pedestrians, such as Hobart, Launceston and Burnie.

Now that a number of traffic signals in these areas have been upgraded, traffic signals in other locations may be upgraded progressively, as they need to be repaired, replaced or modified.

Can I request a crossing be automated?

When deciding whether to automate a crossing, the number one consideration is pedestrian safety.

If you believe a crossing should be automated, please send your request to info@stategrowth.tas.gov.au.

Will more crossings be automated?

We are progressively upgrading crossings, to allow them to be managed remotely.

Locations in Burnie and Ulverstone were reconfigured in April 2020 to allow them to be automated.

We will upgrade equipment through our annual programs to meet our operational requirements, manage older assets or through other projects.

Why the crossings only are automated between 7:00 am and 7:00 pm?

The crossings are not automatic between the hours of 7:00 pm and 7:00 am.

This is because there aren’t many pedestrians during the evening, and we don’t want to hold traffic up unnecessarily – especially at intersections with right-turn signals. It also reduces unnecessary noise during the night, from intersections with audio tactile buttons.

If crossings are automated, why do they still have buttons?

The crossings are not automatic between 7:00 pm and 7:00 am. The button needs to be pressed on these crossings after the automatic period ends.

The buttons are also valuable tools for vision impaired members of the community. The button emits faster ‘beeps’ to tell people when to cross, and the button vibrates in time with the beeps to assist hearing and vision impaired pedestrians. The buttons also have raised arrows, to guide people in which direction to cross.
Intersections where some or all of the crossings operate automatically are listed below.

A crossing didn’t change automatically for me

Not all crossings are automatic. A list of intersections where some or all of the crossings are automatic is included on this page.

Stickers have also been placed on automated crossings, to tell people not to press the button.

Automatic crossings are only automated between the hours of 7:00 am – 7:00 pm. From 7:00 pm – 7:00 am you will need to press the button to trigger the signal.

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.

When issues with traffic signals happen across Tasmania’s State Road network, we perform maintenance or modification works to fix the problem as soon as possible.

These works usually happen at night and may create short periods of noise due to heavy machinery and vehicles. We will try and minimise noise by doing the noisier works earlier in the night.

If you live or are based near one of our traffic signal worksites you may receive a postcard in the mail 1-4 business days before the work starts, with details about the type of work, the dates, times, traffic impacts and noise.

If you have any questions about the postcard mailing process or traffic signals work across Tasmania, you can contact the Traffic Signals Maintenance team by emailing: tsmnotifications@stategrowth.tas.gov.au.