Control unit, Pedestrian Group Type PX-2, metal / plastic / electronic components, made by the Department of Motor Transport, New South Wales, Australia, 1967
The relay-logic controller represents the most advanced state of automatic traffic control devices used in NSW prior to the introduction (in 1973-74) of the worlds first microprocessor based traffic controllers.
The first signalling devices to control street traffic were installed in London in 1868. A semaphore arm was employed to direct traffic during the day and red and green illuminated gas lamps were used at night. Both systems were manually operated by a police officer.
In NSW the state government persisted with the employment of a police officer on active traffic control duty, rejecting all other traffic control systems up until October 13th 1933. On this date the state government commissioned the first vehicle actuated traffic signal to be installed in central Sydney. Four more sets of signals were installed in central Sydney in 1937, and after these proved to be reliable and efficient the number of signals increased rapidly.
In January 1964 the department of Motor Transport commissioned the first stage of co-ordinated traffic control signals in the inner city of Sydney. The PX-2 (pedestrian controller) would have been used as an integral part of this new attempt to link all of the signalling systems of a designated area. The dials on the front display enable the 'walk' and flashing 'don't walk' signal timing to be automatically preset in relation to the size of the pedestrian crossing / intersection involved.
The PX-2 is a key component of a historically novel attempt to synchronise and co-ordinate a system of vehicle regulation, thus replacing a signal system which had been previously only capable of regulating a single un-connected site. The Dept. of Motor Transport developed a novel, interdependent traffic signal system that was under central control and supervised by means of closed-circuit television.
The PX-2 is representative of this historically novel system, features of which were unique in operation to Sydney; traffic engineering in its infancy at the time, Sydney adopts a system with greater flexibility built-in than other similar attempts overseas.
The PX-2 is an example of the continuous development and application of technologies that aim to ensure efficiency, safety, regulation and monitoring in relation to the management of large urban spaces.
Designed and made by the Roads & Traffic Authority, New South Wales, Australia.