History of SCATS Development
Faced with the need to implement a large area traffic control system in Sydney and mindful of the problems of fixed-time systems, the Roads and Traffic Authority, New South Wales (RTA), embarked on the development of a traffic responsive system in the early 1970s when mini-computers became available at a cost comparable to purpose-built hardware which had been used up to that time. The early move into microprocessor local controllers in Australia (1975) provided additional impetus to the development because of the increased intelligence and flexibility available.
SCATS development was undertaken by the RTA for its own purposes (ie the control of traffic signals in NSW cities) but SCATS has since been implemented in many other cities in Australia, New Zealand and overseas. User authorities in Australia and New Zealand form a user group which meets annually to collectively discuss features, improvements, and local usage of SCATS. The Authority has arrangements to market SCATS through the rest of the world.
Many years of research, testing and software coding have been invested in the development of SCATS. Development to further improve SCATS continues to ensure that control of traffic is as efficient as possible and that the needs of new users continue to be met. Many useful improvements to SCATS have been inspired by feedback from the large group of users.
SCATS chronology
- • October 1933 - the first traffic lights were switched on in NSW
- • NSW decided that traffic signals were a State Government responsibility not a Local Government responsibility. This gave rise by the 1960's to an organisation of dedicated specialists with electrical, electronic, construction and traffic engineering skills in the arts of designing, installing and maintaining traffic signals called the DMR (Department of Main Roads).
- • 1963 - the first traffic control system installed in Sydney for 8 intersections using an obsolete IBM 604 rewired by My Arthur Sims who at that time worked for IBM but later became an employee of the DMR.
- • 1964 - a new version was installed capable of controlling 96 intersections.
- • 1965 - 25 intersections were connected to the new traffic control system.
- • DMT built their own intersection vehicle controller and by 1965/66 had a 6 phase controller on the streets.
- • 1967 - it became obvious that valves and relays should be replaced with semiconductors but still considered to expensive at that time. Eventually all 96 intersections were used up and to make more space two intersections were combined to make one thereby allowing more intersections to be connected.
- • 1967/68 - a new system was installed partly solid state to control six intersections in Broadway.
- • 1967 - the forerunner to Flexilink was developed called MASCOT. These MASCOT systems were installed to buy time for the development of SCATS. AWA and Philips Australia manufacture signal controllers with the MASCOT feature built in to the hardware and it is now called Flexilink.
- • 1969/70 - a new rack mount system was commissioned.
- • 1970's - a decision to use the PDP 11 computers for traffic control was made and Arthur Sims joined the DMT and software development stated for SCATS
- • 1976 - the new system developed on the PDP computers became known as SCATS.
- • 1970's - the move to a modern new control centre at No. 1 Oxford Street, Sydney which was to be the centre of SCATS development for over twenty years.
- • 1978 - the first Central Monitoring System (CMS) was installed addressing the need to centrally monitor geographically remote SCATS regions. Its functionality was expanded over subsequent years to provide some data file back up and management facilities.
- • 1981 - the first VAX computer, a VAX 11/780 was purchased, progressively taking over many of the development functions and providing a platform for SCATS management and support functions.
- • 1982 - the acquisition of a RAMTEK graphics display system provided the first graphical display of SCATS related data. Applications to create and display graphical data at the regional, subsystem and intersection levels were developed in-house.
- • 1980's - the first use of personal computers (PC) for the operator interface. Software, known as SCATTERM, was developed to enable these PCs, running Windows® 2.0, to emulate the VDU function and provide additional functions such as file handling and editing
- • 1989 – PC graphics capability was developed to replace the RAMTEK display system.
- • 1990 – version 5 of SCATS in use
- • Early 1990's – largely arising from the specified requirements for a SCATS 5 system to be supplied to Hong Kong further features were developed
- • 1996 – in response to a contract to install SCATS as part of a freeway/arterial integrated corridor project in Minneapolis, development of a traffic adaptive ramp metering function in SCATS which was shown to reduce delay and ramp queuing when compared to the existing MNDoT system.
- • 1998 – the first SCATS 6 was trialled after realising the operating platform for SCATS had to migrate from PDP 11 to PC based computers.
RTA has continually over the years expanded the features of SCATS and added ancillary support software to the SCATS suite. SCATS is now so successful it is sold internationally through distributors.
