HOME

TheInfoList



OR:

The Sydney Coordinated Adaptive Traffic System, abbreviated SCATS, is an intelligent transportation system that manages the dynamic (on-line, real-time) timing of signal phases at
traffic signal Traffic lights, traffic signals, or stoplights – known also as robots in South Africa are signalling devices positioned at road intersections, pedestrian crossings, and other locations in order to control flows of traffic. Traffic light ...
s, meaning that it tries to find the best phasing (i.e. cycle times, phase splits and offsets) for a traffic situation (for individual intersections as well as for the whole network). SCATS is based on the automatic plan selection from a library in response to the data derived from loop detectors or other road traffic sensors. SCATS uses sensors at each traffic signal to detect vehicle presence in each lane and pedestrians waiting to cross at the local site. The vehicle sensors are generally inductive loops installed within the road pavement. The pedestrian sensors are usually push buttons. Various other types of sensors can be used for vehicle presence detection, provided that a similar and consistent output is achieved. Information collected from the vehicle sensors allows SCATS to calculate and adapt the timing of traffic signals in the network. SCATS is installed at about 55,000 intersections in over 180 cities in 28 countries. In Australia, where the system was first developed, the majority of signalised intersections are SCATS operated (around 11,000). The SCATS system is owned by the
Australia Australia, officially the Commonwealth of Australia, is a Sovereign state, sovereign country comprising the mainland of the Australia (continent), Australian continent, the island of Tasmania, and numerous List of islands of Australia, sma ...
n state of
New South Wales ) , nickname = , image_map = New South Wales in Australia.svg , map_caption = Location of New South Wales in AustraliaCoordinates: , subdivision_type = Country , subdivision_name = Australia , established_title = Before federation , es ...
, whose state capital is
Sydney Sydney ( ) is the capital city of the state of New South Wales, and the most populous city in both Australia and Oceania. Located on Australia's east coast, the metropolis surrounds Sydney Harbour and extends about towards the Blue Mountain ...
. In December 2019,
Transport for NSW Transport for NSW, sometimes abbreviated to TfNSW, and pronounced as Transport for New South Wales, is an agency of the New South Wales Government established on 1 November 2011, and is the leading transport and roads agency in New South Wales, ...
, the transport and road agency in New South Wales, began to look into commercialising the SCATS system.


Features


Default operation

The architecture of SCATS is at two basic levels, LOCAL and MASTER. The LOCAL is the control cabinet at the roadside, which provides the normal signal control as well as processing of traffic information deduced from the vehicle detectors. The MASTER is a remote computer which provides area based traffic control, i.e. area traffic control (ATC) or urban traffic control (UTC). Detailed traffic signal and hardware diagnostics are passed from the LOCAL to the MASTER, with the ability to notify staff when a traffic signal has a fault. SCATS is able to operate over PAPL,
ADSL Asymmetric digital subscriber line (ADSL) is a type of digital subscriber line (DSL) technology, a data communications technology that enables faster data transmission over copper telephone lines than a conventional voiceband modem can provide. ...
,
PSTN The public switched telephone network (PSTN) provides infrastructure and services for public telecommunication. The PSTN is the aggregate of the world's circuit-switched telephone networks that are operated by national, regional, or local teleph ...
and 3G IP network connections to each intersection. SCATS can also operate on a network of private cables not requiring third party telecommunications support and large parts of inner Sydney have always operated this way.


Priority levels

Public vehicle priority in SCATS (using data provided from PTIPS) caters for both buses and trams. SCATS has a facility to provide three levels of priority: * High – In the high priority mode the "hurry call" facility is used. (i.e. the phase needed by a bus, tram or emergency vehicle is called immediately, skipping other phases if necessary) * Medium (''Flexible window'') – Phases can be shortened to allow the bus/tram phase to be brought in early. The bus/tram phase can occur at more than one place in the cycle. * Low – takes its turn. Trams would normally be given high priority, the aim of which is to get the tram through without it stopping. Buses would normally expect to receive a medium level of priority.


Instant fault detection and quick repair

The ATC system is equipped with the function of fault detection and logging the fault detected in order to facilitate repair and maintenance. Should there be a telecommunication breakdown, the ATC junction controller concerned will switch to standalone mode and continue to function.


Traffic Adaptive Operation

ATC systems provide advanced method of traffic signal control called Traffic Adaptive Control where the operational timing plans including cycle length, splits and offsets are continuously reviewed and modified in small increment, almost on a cycle-by-cycle basis, to match with the prevailing demand measured by the detectors connected to the on-street traffic controllers.


SCATS Ramp Metering System

The SCATS Ramp Metering System (SRMS)Aydos J.C., O'Brien A. ''SCATS Ramp Metering: Strategies, Arterial Integration and Results'', Proceedings of the 17th International IEEE Conference on Intelligent Transportation Systems, Qingdao, 2014 is a SCATS subsystem and controls traffic signals at the entries of motorways and integrates with SCATS intersection control for promoting integrated real-time management of the traffic corridor as a whole. The objective of SRMS, based on current traffic conditions, is to efficiently determine: * When ramp metering signals start and end ramp metering operation * The metering flow rates of the operating ramp metering signals * Which actions shall be taken to signalised intersections of the corridor to promote network-wide benefits. SRMS achieves these objectives by implementing a collection of pre-configured adaptive intelligent strategies either automatically or manually. In manual mode, the SRMS operator can create new or manipulate existing rules in order to adjust the ramp metering system for effective operation during any planned or unplanned events (e.g. incidents). SRMS is a distributed control system that operates on a central control server and road-side traffic controllers. The central control server is a component of SCATS and inherently provide integrated motorway and arterial real-time management. The road-side controllers are installed on motorway on-ramps and are used to: * Set the traffic signal times * Set the state of on-ramp changeable signs * Manage the sequences start and end ramp metering operation; and * Measure traffic states using vehicle detectors. Metering rates are determined by the local traffic signal controller or by the central control server. Metering rates can be determined in two ways: * adaptive operation, or * time-of-day-based operation typically when a communications failure or critical vehicle detector failures take place The adaptive operation optimises mainline traffic state by using real-time data from vehicle detector stations installed at several mainline locations, ramps and optionally at arterial roads. The adaptive operation determines control actions at 10 seconds intervals and applies some or all of the following strategies simultaneously: * Coordinated ramp metering * Ramp queue management * Automatic begin and end of ramp metering operation * Variation routines for integration with SCATS intersection control * Variation routines for automated incident responses and unusual circumstances * Manual controls for incident responses and unusual circumstances * Critical lane occupancy calibration * Fault-tolerant strategies * Data logging for performance reporting and off-line analysis SRMS is currently used as the Auckland ramp metering system.


Simulation

SCATS can be simulated in-the-loop (SCATSIM) using third party traffic simulation tools. SCATSIM offers an interface supported by
Aimsun Aimsun is a software company that provides simulation software and services for transportation planning and traffic management. Overview Aimsun was founded in 1997 and developed Aimsun Next traffic modeling software, which simulates mobility in ...
,
PTV VISSIM PTV Vissim is a microscopic multi-modal traffic flow simulation software package developed by PTV Planung Transport Verkehr AG in Karlsruhe, Germany. The name is derived from "Verkehr In Städten - SIMulationsmodell" (German for "Traffic in citi ...
,
Quadstone Paramics Paramics is traffic microsimulation software, originally developed by Quadstone Ltd. There is a related pedestrian microsimulation product called the Urban Analytics Framework. Background The Paramics project was originally established in the ea ...
and Commuter. SCATSIM offers kerb-side hardware and firmware emulation that interfaces seamless to the SCATS Region and Central Manager offering the same control strategies used in field deployments for both intersections and ramp metering (
SRMS Canadarm or Canadarm1 (officially Shuttle Remote Manipulator System or SRMS, also SSRMS) is a series of robotic arms that were used on the Space Shuttle orbiters to deploy, manoeuvre, and capture payloads. After the Space Shuttle ''Columbia'' ...
). The configuration files prepared by authorities for the Central Manager, Region,
SRMS Canadarm or Canadarm1 (officially Shuttle Remote Manipulator System or SRMS, also SSRMS) is a series of robotic arms that were used on the Space Shuttle orbiters to deploy, manoeuvre, and capture payloads. After the Space Shuttle ''Columbia'' ...
and kerb-side controllers can be re-used without modification by SCATSIM. When Commuter software was acquired by Autodesk, Azalient Ltd support for the Commuter interface was deprecated. Azalient Ltd also developed a plugin that enabled the
Quadstone Paramics Paramics is traffic microsimulation software, originally developed by Quadstone Ltd. There is a related pedestrian microsimulation product called the Urban Analytics Framework. Background The Paramics project was originally established in the ea ...
interface to SCATSIM. This plugin is also deprecated.


History

SCATS was developed in
Sydney Sydney ( ) is the capital city of the state of New South Wales, and the most populous city in both Australia and Oceania. Located on Australia's east coast, the metropolis surrounds Sydney Harbour and extends about towards the Blue Mountain ...
,
Australia Australia, officially the Commonwealth of Australia, is a Sovereign state, sovereign country comprising the mainland of the Australia (continent), Australian continent, the island of Tasmania, and numerous List of islands of Australia, sma ...
by the New South Wales Department of Main Roads (a predecessor of
Transport for NSW Transport for NSW, sometimes abbreviated to TfNSW, and pronounced as Transport for New South Wales, is an agency of the New South Wales Government established on 1 November 2011, and is the leading transport and roads agency in New South Wales, ...
) in the 1970s. It began to be used in
Melbourne Melbourne ( ; Boonwurrung/Woiwurrung: ''Narrm'' or ''Naarm'') is the capital and most populous city of the Australian state of Victoria, and the second-most populous city in both Australia and Oceania. Its name generally refers to a met ...
in 1982, Adelaide, South Australia in 1982 and
Western Australia Western Australia (commonly abbreviated as WA) is a state of Australia occupying the western percent of the land area of Australia excluding external territories. It is bounded by the Indian Ocean to the north and west, the Southern Ocean to th ...
in 1983. It is also used in
New Zealand New Zealand ( mi, Aotearoa ) is an island country in the southwestern Pacific Ocean. It consists of two main landmasses—the North Island () and the South Island ()—and over 700 smaller islands. It is the sixth-largest island count ...
,
Hong Kong Hong Kong ( (US) or (UK); , ), officially the Hong Kong Special Administrative Region of the People's Republic of China ( abbr. Hong Kong SAR or HKSAR), is a city and special administrative region of China on the eastern Pearl River Delt ...
,
Shanghai Shanghai (; , , Standard Mandarin pronunciation: ) is one of the four direct-administered municipalities of the People's Republic of China (PRC). The city is located on the southern estuary of the Yangtze River, with the Huangpu River flow ...
,
Guangzhou Guangzhou (, ; ; or ; ), also known as Canton () and alternatively romanized as Kwongchow or Kwangchow, is the capital and largest city of Guangdong province in southern China. Located on the Pearl River about north-northwest of Hong Kon ...
,
Amman Amman (; ar, عَمَّان, ' ; Ammonite language, Ammonite: 𐤓𐤁𐤕 𐤏𐤌𐤍 ''Rabat ʻAmān'') is the capital and largest city of Jordan, and the country's economic, political, and cultural center. With a population of 4,061,150 a ...
,
Tehran Tehran (; fa, تهران ) is the largest city in Tehran Province and the capital of Iran. With a population of around 9 million in the city and around 16 million in the larger metropolitan area of Greater Tehran, Tehran is the most popul ...
,
Dublin Dublin (; , or ) is the capital and largest city of Republic of Ireland, Ireland. On a bay at the mouth of the River Liffey, it is in the Provinces of Ireland, province of Leinster, bordered on the south by the Dublin Mountains, a part of th ...
,
Rzeszów Rzeszów ( , ; la, Resovia; yi, ריישא ''Raisha'')) is the largest city in southeastern Poland. It is located on both sides of the Wisłok River in the heartland of the Sandomierz Basin. Rzeszów has been the capital of the Subcarpathian Vo ...
,
Gdynia Gdynia ( ; ; german: Gdingen (currently), (1939–1945); csb, Gdiniô, , , ) is a city in northern Poland and a seaport on the Baltic Sea coast. With a population of 243,918, it is the List of cities in Poland, 12th-largest city in Poland and ...
,
Central Central is an adjective usually referring to being in the center of some place or (mathematical) object. Central may also refer to: Directions and generalised locations * Central Africa, a region in the centre of Africa continent, also known as ...
New Jersey New Jersey is a state in the Mid-Atlantic and Northeastern regions of the United States. It is bordered on the north and east by the state of New York; on the east, southeast, and south by the Atlantic Ocean; on the west by the Delaware ...
, and in part of
Metro Atlanta Metro Atlanta, designated by the United States Office of Management and Budget as the Atlanta–Sandy Springs–Alpharetta, GA Metropolitan Statistical Area, is the most populous metropolitan statistical area in the U.S. state of Georgia and the ...
,ATCS being implemented in Metro Atlanta
/ref> among several other places. In Hong Kong, SCATS is currently adopted in the area traffic control systems at Hong Kong Island, Kowloon, Tsuen Wan and Shatin. The system may be referred to by an alternative name in a specific installation. However, since deployment outside Australia, New Zealand and Singapore, localised names do not appear to be commonly used. The following are some local alternative names that have been or are in use: *
Canberra Canberra ( ) is the capital city of Australia. Founded following the federation of the colonies of Australia as the seat of government for the new nation, it is Australia's largest inland city and the eighth-largest city overall. The ci ...
"CATSS" (Canberra Automated Traffic Signal System) *
Melbourne Melbourne ( ; Boonwurrung/Woiwurrung: ''Narrm'' or ''Naarm'') is the capital and most populous city of the Australian state of Victoria, and the second-most populous city in both Australia and Oceania. Its name generally refers to a met ...
"SCRAM" (Signal Co-ordination for Regional Areas of Melbourne) *
Adelaide Adelaide ( ) is the capital city of South Australia, the state's largest city and the fifth-most populous city in Australia. "Adelaide" may refer to either Greater Adelaide (including the Adelaide Hills) or the Adelaide city centre. The dem ...
"ACTS" (Adelaide Co-ordinated Traffic Signals) *
Perth Perth is the capital and largest city of the Australian state of Western Australia. It is the fourth most populous city in Australia and Oceania, with a population of 2.1 million (80% of the state) living in Greater Perth in 2020. Perth is ...
"PCATS" *
Singapore Singapore (), officially the Republic of Singapore, is a sovereign island country and city-state in maritime Southeast Asia. It lies about one degree of latitude () north of the equator, off the southern tip of the Malay Peninsula, borde ...
"GLIDE" *
Northern Territory The Northern Territory (commonly abbreviated as NT; formally the Northern Territory of Australia) is an states and territories of Australia, Australian territory in the central and central northern regions of Australia. The Northern Territory ...
"DARTS" SCATS is a recognised worldwide market leader in intelligent transport systems.
Transport for NSW Transport for NSW, sometimes abbreviated to TfNSW, and pronounced as Transport for New South Wales, is an agency of the New South Wales Government established on 1 November 2011, and is the leading transport and roads agency in New South Wales, ...
is continuing to develop SCATS to meet emerging technological, user and traffic demands.


See also

* PTIPS - works together with SCATS to provide transport vehicles with priority at traffic signals Other Intelligent Transportation Systems include: *
STREAMS A stream is a continuous body of water, body of surface water Current (stream), flowing within the stream bed, bed and bank (geography), banks of a channel (geography), channel. Depending on its location or certain characteristics, a stream ...
*
BLISS BLISS is a system programming language developed at Carnegie Mellon University (CMU) by W. A. Wulf, D. B. Russell, and A. N. Habermann around 1970. It was perhaps the best known system language until C debuted a few years later. Since then, C b ...
* Inductive loop vehicle detection


References

{{Reflist


External links


Roads ACTRoads and Maritime Services, NSWSCATS - Sydney Coordinated Adaptive Traffic System WebsiteSCATS - Main Roads Western AustraliaReview of Bus Priority at Traffic Signals around the World
Intelligent transportation systems Traffic signals