Typical signal design used in the ACT until the early 90s, and still in use in Victoria, Northern Territory and South Australia. This signal was located on the junction of Canberra Avenue and National Circuit, Forrest, ACT, and has since been replaced with an LED lantern with a white-bordered target board. Image © Sam Laybutt (Ozroads)

General Information:

Traffic lights are installed to regulate traffic flow and make driving safer, and first started appearing in Australia in the early 20th century. There were various types and sequences, which will be covered in this section. This section features signal location and installation information and features a photo and video gallery of signals in operation.

Over the years, several different manufacturers have supplied signals to the various state and territory road authorities, these companies include, but are not limited to, ATS / Aldridge Traffic Systems, AWA (Amalgamated Wireless Australasia) / AWA Plessey, Bob Panich, Braums, Eagle Signal Company of Australia, Excelsior, Excel Technology Group, Gulf & Western, Marshalite, Philips, QTC Traffic Solutions and Siemens.

Australian traffic lantern sequences work as follows: red, green, amber, red. However in some states, although now officially phased out, the signal sequence was red, red-amber, green, amber, red. Well into the first decade of the 21st century, there were still some signals in suburban Melbourne using this configuration. The video gallery features a video of a set in operation as well as all the common signal types seen today.

Australia's First Traffic Signals:

The first ever traffic signals installed and operating in Australia were in Adelaide in South Australia. The list below explains when and where the first set of traffic lights were installed in each capital city:

Adelaide: King William Street, Hindley Street & Rundle Street, December 1927. They were a Swedish-made stop-go set with red and green lights. The three-colour system was not installed until April 1937. ¹ Adelaide's first suburban lights were installed a decade later at the intersection of South Road & Henley Beach Road, Torrensville. ²

Brisbane: Ann Street, Upper Street, Albert Street & Roma Street, 21 January 1936. At precisely 3 pm, Mr E M Hanlon, Minister for Health and Home Affairs, switched on the electro-matic vehicle activated, traffic control system. The traffic lights were set to operate each day between 7:30 am and midnight. ³ During the 1960s, the city's signals would switch from normal phasing to flashing amber overnight. ⁴

Canberra: Northbourne Avenue & London Circuit and Northbourne Avenue, Boldrewood Street (now Barry Drive) & Cooyong Street, 23rd October 1965. ⁵

Darwin: Daly Street & Mitchell Street, Daly Street & Smith Street, Daly Street & Cavenagh Street, Daly Street & Wood Street and Daly Street & McMinn Street, 22nd February 1973. ⁶

Hobart: Elizabeth Street and Liverpool Street, 26 January 1937. The system was fully automatic and was switched on by the then Premier (Mr A G Ogilvie), the then Hobart Lord Mayor (Mr J J Wignail), the then Minister of Agriculture (Mr R Cosgrove), and the then Commissioner of Police (Colonel J E C Lord). ⁷

Melbourne: Swanston Street & Flinders Street, 1928. These were manually operated and removed after one year. At Swanston and Collins Street, mechanically and manually operated signals were installed in 1929. ⁸

Sydney: Kent Street & Market Street, 13 October 1933. ⁹

Perth: Railway Parade & Sutherland Street, West Perth, 19 December 1953. ¹⁰ Until this time Western Australia had relied on police officers performing point duty to control traffic. ¹ Main Roads Commissioner John Leach decided in 1951 to examine the possibility of using traffic lights and asked Don Aitken (future Commissioner who was on leave in London at the time) to conduct investigations on the British use of traffic lights. Aitken recommended that traffic counts should be undertaken at all city intersections to ascertain where lights would be most appropriate. After university students had counted about 20 intersections in the CBD, the decision was made to put the first set of lights at the West Perth subway (intersection of Railway Parade & Sutherland Street) in December 1953. Soon afterwards four sets were installed on William St, all of them vehicle actuated to make traffic flows more efficient. ¹¹

How Traffic Signals Operate:

Several components make up a traffic signal set. A standard set of traffic signals consists of: ¹²

Traffic Signal Controller: This 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. It can operate in a 'standalone' way (known as isolation mode), or it can be programmed to coordinate with a series of nearby traffic signals (known as coordinated mode).

Vehicle Detector Loops and Pedestrian Push Buttons: Vehicle loop detectors and pedestrian push buttons (known as call buttons) make the controllers acknowledge someone is waiting for a green signal, 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. This loop tells controller 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 Lanterns: Traffic signal lights are how the controller directs traffic. They tell the road users when to go and when to stop. 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.

Posts, pits and underground electrical cables: These are all essential to connect all the components together.

Traffic Signal Video and Photo Gallery plus Signal Database:

To view each section, click or tap on a section name or preview image below.