The Sydney Coordinated Adaptive Traffic System (SCATS) is an intelligent transportation system that optimizes traffic signal timing to improve traffic flow and reduce congestion, pollution, and accidents. It has been implemented in various cities worldwide, including Sydney, Melbourne, and Amman, with reported benefits such as reduced travel times and emissions. The system utilizes real-time data and algorithms to adjust signal timings based on current traffic conditions, promoting a more efficient traffic management approach.

1. Jordan University of Science and Technology
Department of Civil Engineering
CE 345
Transportation engineering
Assignment 1: the Sydney Coordinated Adaptive
Traffic System (SCATS)
Dr. Bashar Hani Al-Omari
Student name: Anas Omar Ghawanmeh
Student no.: 123874
Section no. : 3

2. Introduction:
The Sydney Coordinated Adaptive Traffic System (SCATS) is a system that
connects the light signals in the city with each other through a single optical
signal under one system, so that it reduces traffic volumes and also reduces
environmental pollution and reduces traffic accidents. And increase the
carrying capacity of the road.
SCATS is a traffic control system designed to optimize traffic flow. Intelligent
algorithms process real-time data to adapt traffic signal timings that respond
to unexpected conditions, predict traffic patterns and keep traffic moving. The
result is a reduction in congestion, shorter journey times and increased safety
and productivity.
As the number of vehicle in urban areas is ever increasing, it has been a major
concern of city authorities to facilitate effective control of traffic flows in urban
areas .Especially in rush hours, even a poor control at traffic signals may result
in a long time traffic jam causing a chain of delays in traffic flows and also CO2
emission. Vehicle’s engine idling time consumes more fuels and releases more
CO2 than the vehicle in motion states. Thus if vehicle’s idling time can be
reduced, the amount of CO2 emission can be decreased. Also nobody likes to
stop at the intersection, Spending a lot of time at the intersection may lead to:
Driving pressure. In many cities, these demands are increasing It cannot be
met by extension the existing road infrastructure gives a special advantage the
importance of effective use of what is there Network. In this respect, traffic
lights are a vital factor because good control strategies are often able to
Optimize network traffic flows. To reduce the waiting time for vehicles at
traffic lights is Reducing fuel consumption and working hours, and thus it is
Important to effectively control traffic lights.
OBJECTIVE:
Describe the main characteristics of the Sydney Coordinated
Adaptive Traffic System (SCATS) and its use in 3 worldwide
cities. Clarification and explanation about the system and
making a comparison between three large cities that use
this system and detailing the advantages and
disadvantages of this system in each city that used it.

3. ABSTRACT:
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 signals, 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.
The Sydney Coordinated Adaptive Traffic System, abbreviated SCATS, is an
intelligent transportation system developed in Sydney, Australia by former
constituents of the Roads and Maritime Services in the 1970s, used in
Melbourne since 1982[1] and Western Australia since 1983.[2] It is also used in
New Zealand, Hong Kong, Shanghai, Guangzhou, Amman, Tehran, Dublin,
Rzeszów, Gdynia and soon in part of Metro Atlanta,[3] among several other
places. The system may be referred to by an alternative name in a specific
installation (except Sydney), although since deployment wider than Australia,
New Zealand and Singapore, these localised names do not appear to be
commonly used. The following are some local alternative names that have
been or are in use:
Canberra "CATSS" (Canberra Automated Traffic Signal System)
Melbourne "SCRAM"
Adelaide "ACATS"
Perth "PCATS"
Singapore "GLIDE" (1)
Literature review:
Amman (Jodan)
Following individual improvements made to a number of roundabouts and
intersections in Amman, Jordan, the decision was taken to improve traffic
management throughout the city by building a new traffic control centre and
implementing an ITS solution. Details are provided of the connection of
96intersections to the existing Sydney Coordinated Adaptive Traffic System
(SCATS) and the installation of CCTV surveillance. The system automatically
monitors traffic at approaches to intersections, adjusts cycle times, green splits
and offset cycles to suit the current conditions and provides an adaptive green

4. wave. A particular challenge was the communication system which was
originally to be based on the use of analog phone lines but had to be changed
to 512 Kb digital VPN lines. As well as improving traffic flow and travel times,
benefits of the scheme include reduced emissions, improvements to the
economy of the area, incident detection and the gathering of valuable traffic
data. (2)
Cities in Australia (Sydney)
The Department of Main Roads, New South Wales is currently installing a
tuck system of 1,000 sets of traffic signals in the Sydney metropolitan area
of 1500 km2. The system comprises 11 regional minicomputers which are
supervised by one centrally located minicomputer. All of the local
controllers are microcomputers. The system architecture is one of
distributed intelligence with a comprehensive and flexible communication
system. An important feature is its integral cable less link mode of
operation as a fall back option. The plans and schedules for this operation
are stored in the microcomputers from the regional computer and the local
clocks are regularly checked. The normal mode of coordination is the
dynamic method first developed for the Sydney CBD system of 150 sets of
signals. The method dynamically adjusts cycle, split and offsets in response
to variations in traffic demand and capacity. Sufficient evidence exists to
show that the method can produce significant improvements in delay
reduction when compared to the optimized fixed time methods preferred
by most other authorities. The system design incorporates facilities for
centralized volume counting, control of reversible lanes and variable
message signs (a). (3)
Park City, UT
This paper reports on the field evaluation of the Sydney Coordinated
Adaptive Traffic System (SCATS) that was installed in Park City (Utah) in
2005 on its network of 14 signalized intersections. Park City was selected as
a deployment site since it is a fast-growing area which often experiences
significant shifts in traffic demand due to its frequent recreational and
artistic events. SCATS uses information from vehicle detectors, located in
each lane immediately in advance of the stop line, to adjust signal timings in
response to variations in traffic demand and system capacity. The objective
of SCATS deployment was to reduce travel times, vehicle delays, and

5. number of stops in the network. The evaluation compared previous time-
of-day actuated-coordinated signal timings with those dynamically
computed by SCATS. Travel times, travel time stopped delay and number of
stops were collected by driving probe vehicles on the major routes. Travel
time stopped delay was measured as stopped time experienced during the
travel time runs, mostly due to waiting at traffic signals. Information on
intersection stopped delays was also collected to investigate traffic
performance on side streets. Overall, SCATS consistently reduced travel
times and travel time stopped delay, lessened the average number of stops,
and lowered intersection stopped delay for major and minor through
movements of traffic. In addition, the SCATS installation is expected to
reduce operational costs to maintain proper signal timings and coordination
on the Park City network. (4)
Discussion:
1 -THE HISTORY OF ITS DEVELOPMENT
Intelligent Transport Systems is a term which has entered the lexicon in
comparatively recent years, so we tend to forget that some systems have a
pedigree extending back several decades. This is the story of one such system -
the Sydney Coordinated Adaptive Traffic System (SCATS). The beginnings of
SCATS can be traced back to the installation of the first set of traffic signals at
the corner of Market and Kent Streets Sydney on Friday 13 October 1933. The
then Department of Road Transport and Tramways (later the Department of
Motor Transport) was charged with the responsibility for maintenance and
subsequent installation of additional signals, largely because it employed
people with electrical skills (for the tramways). This tiny seed, which can be
said to have led to the development of SCATS, was nurtured by the decision to
undertake maintenance in-house rather than leaving it to the equipment
suppliers. Another nutrient was that responsibility for signals was not
fragmented as in many other states where local councils often looked after
traffic signals. By the mid-fifties, the department had built a small team of
dedicated specialists in the arts of designing, installing and maintaining traffic
signals. Electrical, construction and traffic engineering skills were present and
this team continued to expand through the sixties. The real history of SCATS
begins at this time when the need for some type of coordination between
closely spaced traffic signals became apparent. This paper presents a history of
the development of SCATS.

6. 1 -Microsimulation Evaluation of Benefits of SCATS-
Coordinated Traffic Control Signals
The development of micro-simulation traffic modeling software over the last
decade has greatly contributed to the traffic engineer’s tools that are available
for analyzing complex traffic conditions and evaluating traffic management
solutions. This paper reports on just one application, the evaluation of an area
wide traffic control system using fixed time versus co-ordinated adaptive
timing strategy for traffic signals. The SCATS (Sydney Co-ordinated Adaptive
Traffic System) software is developed by the Roads and Traffic Authority (RTA)
of New South Wales, Australia and has recently been adapted to communicate
with vehicle-based simulation software. SCATS is not only used in Australia but
throughout the world including USA, Mexico, and Asia. The traffic simulation
model replaces the vehicles in the real world and transmits detector actuation
messages SCATS central computer. These messages (detector “on”, detector
“off”) are passed to the WinTraff software which emulates the personality
logic of the local signal controller. After WinTraff has pre-processed the
detector messages it passes data (traffic flow, non-occupancy etc.) to the
SCATS simulation version. This version is the same as the real world SCATS
except it runs faster than real time and has some house keeping processes. The
combined software of WinTraff and SCATS in simulation is referred to as
SCATSIM. Enabling SCATS to interface with micro-simulation models opens up
a whole new range of possibilities in system optimization and evaluation, ITS
application testing, and so on. The results reported in this paper demonstrate
significant traffic benefits gained from co-ordinated adaptive strategies

7. .
Conclusion:
This paper discuss a proposed systems for predicting the next intersection
timing and generating the required speed at current intersection to cross next
intersection without stopping at it. The system is speed module for next
Intersection prediction embedded in intelligent traffic light control system at
intersection. For efficiently predicting the time and speed required for crossing
next intersection without stopping at it centralized static approach is taken
into account, the distance between current intersection and next intersection
and traffic signal timings of next intersection are considered as input to the
system. The traffic signal timings are more on highway than on city road.
System then generates the required speed in range to cross next intersection
without stopping at it. Speed generated by the system is in specified range like
32Km/Hr to 40 Km/Hr. Also it can’t exceed the speed limit of road.
References:
1- http://dictionary.sensagent.com/sydney%20coordinated%20adaptive%2
0traffic%20system/en-en/#anchorWiki
2- https://trid.trb.org/view/981055
3- https://trid.trb.org/view/1206560
4- https://trid.trb.org/view/902224
5- https://trid.trb.org/Results?q=&serial=%228th%20World%20Congress%2
0on%20Intelligent%20Transport%20Systems%22