task 2 urban traffic management system

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FACULTY OF ENGINEERING

DEPARTMENT OF CIVIL AND STRUCTURAL

ENGINEERING

KKKA 6424

INTELLIGENT URBAN TRAFFIC CONTROL SYSTEM

Ir. Dr. Riza Atiq Abdullah O.K. Rahmat

ASSIGNMENT (2)

PREPARED BY:

1- HAIDER FARHAN P65405

2- MUSTAFA TALIB P60915

3-- SAHAR ABD ALI P65295

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1- MAXBAND

1.1 Overview

MAXBAND model of bandwidth optimization assumes that all the vehicles have the

same speed. But there is traffic flow dispersion because of different vehicle

performance. Traffic flow dispersion has been described by Normal Distribution and

Geometric Distribution.

MAXBAND is the only operational traffic signal program that allows progression

bandwidth optimization in multiarterial, closed-loop traffic signal networks. The program

formulates the problem as a mixed integer linear program and is capable of optimizing

network-wide cycle length, signal offsets, and signal phasing sequences. However,

hours of computer time may be required to optimize a medium-sized network problem,

even on a mainframe computer. This computational inefficiency of MAXBAND makes it

impractical for use by the traffic engineering community.

1.2 MAXBAND photos

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1.3 Features and Evaluation

MAXBAND has two heuristic methods efficiently optimize network signal timing

problems modeled. The experimental results demonstrate that these heuristic methods

produce tremendous savings in the computer time required to solve optimization

problems in traffic network signal timing. In addition, computational benefits are

achieved by explicitly modeling one-way arterials in a network rather than as two-way

arterials.

In MAXBAND, vehicles are loaded on an arterial and traffic signals on that arterial are

coordinated to optimize a performance criterion, which often relates to the number of

stops.

2-SCATS System

2.1 Overview

The Sydney Coordinated Adaptive Traffic System (SCATS) is an innovative

computerized traffic management system developed and maintained by roads and

maritime services (RMS) . SCATS has been faced with the need to implement a large

area traffic control system in Sydney and mindful of the problems of "fixed-time"

systems, the NSW Department of Main Roads (now Roads and Maritime Services)

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.

Aldridge Traffic Controllers (ATC) are an RTA authorized Distributor of the world leading

SCATS™ Urban Traffic Management Control (UTMC) System.

Many years of research, testing and software coding have been invested in the

development of SCATS. As of February 2012, SCATS has been distributed to 258 cities

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in 26 countries worldwide controlling more than 34,943 intersections worldwide ,

including installations in Australia, Bangladesh, Brazil, Brunei, Chile, China, Ecuador,

Fiji, Indonesia, Iran, Ireland, Israel, Jordan, Laos, Malaysia, Mexico, New Zealand,

Philippines, Poland, Qatar, Singapore, South Africa, Thailand, USA and Vietnam.

2.2 SCATS photos

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SCATS uses anticipatory and adaptive techniques to increase the eefficiency of the

road network by minimizing the overall number of vehicular stops and delay .

The primary purpose of the SCATS system is to maximize the throughput of a roadway

by controlling queue formation . SCATS system has the ability to change the signal

phasing , timing stratiges and the signal coordination within a network to alleviate

congestion by automatically adjusting the signal parameters according to real time

traffic demand .

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SCATS operates at two basic levels known as the “upper level” which involves offset

plan selection and the “lower level” which involves optimisation of junction parameters.

The upper level generates offset plans by time of day from historic data while the lower

junction level optimizes green splits,cycle times and offsets between signalised

junctions using an increamental feedback processs based largely on detectors situated

at the stop lines . It calculates green splits based on the flow in the previous cycle and

so is not fully responsive to unpredictable arrival flows .

SCATS is basically a modular system largely run by regional computers capable of

handling a large number of intersections with significient intelligence within local

controllers and may be used to improve management function by central computer .

SCATS charactarised by the network manager has a more direct involvement than

other systems in setting up the system .

2.4 Application

Most of Highway operator in Malaysia using SCATS to control their traffic Lights in

urban area. These very popular SCATS is an area wide traffic management system that

operates under the Windows environment. It controls the cycle time, green splits and

offsets for traffic control intersections and mid - block pedestrian crossings. With the

inclusion of vehicle detectors, it can adaptively modify these values to optimize the

operation to suit the prevailing traffic. Alternatively, it can manage intersections in fixed-

time mode where it can change plans by time of day, day of week. It is designed to

coordinate traffic signals for networks or for arterial roads.

Intersection connections to a regional traffic control computer can be permanent or may

be on-demand using dial-in or dial-out facilities. Each regional computer can manage up

to 250 intersections. A SCATS system can have up to 64 regional computers.

Monitoring is provided by a graphical user interface. Up to 100 users can connect to a

SCATS central manager at the same time. Up to 30 users can connect to a single

regional computer simultaneously. Performance monitoring, alarm condition notification

and data configuration facilities are included. SCATS automatically collect alarm and

event information, operational and performance data and historical data. SCATS

operate automatically but operation intervention is provided for use in emergencies.

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2.5 Benefit

The popular concept is that coordinating traffic signals is simply to provide green-wave

progression whereby a motorist travelling along a road receives successive green

signals. While this is one of the aims, the principal purpose of the control system is to

minimize overall stops and delay and, when traffic demand is at or near the capacity of

the system, to maximize that capacity (throughput) and minimize the possibility of traffic

jams by controlling the formation of queues. Can be upgraded or expanded to meet

changing requirements, other applications can be integrated into the system and

provides details/reports of traffic flows for other planning purposes. SCATS enable a

hierarchical system of fall back operation in the event of temporary communications

failure. Such equipment faults are monitored by the system

3-SCOOT

3.1 Overview

SCOOT (Split Cycle Offset Optimisation Technique) was developed in the United

Kingdom by Transport Research Laboratory (TRL) . SCOOT has proved to be an

effective and efficient tool for managing traffic on signalised road networks and is now

used in over 130 towns and cities in UK and overseas world wide.

It coordinates the operation of all the traffic signals in an area to give good progression

to vehicles through the network. Any adaptive traffic control system relies upon good

detection of the current conditions in real-time to allow a quick and effective response to

any changes in the current traffic situation. SCOOTS has a substantial data base facility

for storing , manipulating and presenting traffic data including flows , journey times and

queues . . It has three optimisation procedures by which it adjusts signal timings these

are the cycle time, green splits, and offsets , each optimised using a differenet

procedure at different frequences

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3.2 SCOOT Photos


SCOOT uses detectors at the upstream end of links to measure demand and cyclic flow

in real time and the operation has considerable flexibility to override values and set

parameters for different regions and different times. Theoretically, the benefits of

SCOOT should be highest when traffic flow is heavy, complex and unpredictable.

SCOOT can prevent congestion by delaying it long enough to permit a short duration

overload to be completely overcome .

SCOOT evaluates the advisability of altering the cycle offset at the intersection with

respect to the master schedule by four seconds in either direction. Every five minutes it

explores the option of changing the cycle length for individual subareas, usually

consisting of three to four intersections. SCOOT makes about 10,000 decicions per

hour for every 100 intersection in the system all made by central computer. When

SCOOT detects that saturation levels are unacceptable , it reacts with actions at a

distance. SCOOT naturally reduces vehicle emissions by reducing delays and

congestion within the network and can be set to adjust the optimisation of the signal

timings to minimise emissions , also to provide estimations of harmful emissions within

the controlled area.

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3.4 Application

Information on the physical layout of the road network and how the traffic signals control

the individual traffic streams are stored in the SCOOT database. Any adaptive traffic

control system relies upon good detection of the current conditions in real-time to allow

a quick and effective response to any changes in the current traffic situation. SCOOT

detects vehicles at the start of each approach to every controlled Intersection. It models

the progression of the traffic from the detector through the stop line, taking due account

of the state of the signals and any consequent Queues. The information from the model

is used to optimize the signals to minimize the network delay.

The operation of the SCOOT model is summarized in the diagram above. SCOOT

obtains information on traffic flows from detectors. As an adaptive system, SCOOT

depends on good traffic data so that it can respond to changes in flow. Detectors are

normally required on every link. Their location is important and they are usually

positioned at the upstream end of the approach link. Inductive loops are normally used,

but other methods are also available. When vehicles pass the detector, SCOOT

receives the information and converts the data into its internal units and uses them to

construct "Cyclic flow profiles” for each link. The sample profile shown in the diagram is

color coded green and red according to the state of the traffic signals when the vehicles

will arrive at the stop line at normal cruise speed. Vehicles are modeled down the link at

cruise speed and join the back of the queue (if present). During the green, vehicles

discharge from the stop line at the validated saturation flow rate.

The data from the model is then used by SCOOT in three optimizers which are

continuously adapting three key traffic control parameters - the amount of green for

each approach (Split), the time between adjacent signals (Offset) and the time allowed

for all approaches to a signaled intersection (Cycle time). These three optimizers are

used to continuously adapt these parameters for all intersections in the SCOOT

controlled area, minimizing wasted green time at intersections and reducing stops and

delays by synchronizing adjacent sets of signals. This means that signal timings evolve

as the traffic situation changes without any of the harmful disruption caused by

changing fixed time plans on more traditional urban traffic control systems.

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3.5. Benefit

Throughout its life SCOOT has been enhanced, particularly to offer an ever wider range

of traffic management tools. The traffic manager has many tools available within

SCOOT to manage traffic and meet local policy objectives SCOOT detectors are

positioned where they will detect queues that are in danger of blocking upstream

junctions and causing congestion to spread through the network SCOOT will

continuously monitor the sensitive area and smoothly impose restraint to hold traffic in

the specified areas when necessary. SCOOT naturally reduces vehicle emissions by

reducing delays and congestion within the network. In addition it can be set to adjust the

optimization of the signal timings to minimize emissions and also provide estimations of

harmful emissions within the controlled area.

4- ITACA

4.1 Overview

ITACA ( Intelligent Traffic Area Control Agent) has an adaptive subsystem that operates

with a traffic model and produces cycle split and offset times for a centralized area of

traffic control. These times minimise delay and stops of traffic moving in the area

.ITACA provides real time urban traffic control by computing the best solution for every

intersection and continuously adapting signal sequences to match traffic demand.

The system produces small and frquent changes in traffic control parameters that

smoothly adapt the traffic control plan to evolving changes in traffic demand. In this way,

the negative effects on the network that otherwise would be caused by plan changes

such as, flow disturbances and time delays in establishing flow are avoided.

ITACA is an integral solution for traffic management in urban areas, providing the

capability to control traffic intelligently in real-time, while constantly adapting to changing

traffic needs. This system will help improve the quality of life for the more than 2.5

million inhabitants in the Cities worldwide , by increasing traffic flow efficiency, while

reducing congestion and air pollution.

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4.2 ITACA PHOTOS


ITACA is occupying of enhancement to every 5 seconds on carry on a time of collection

and processing to the transportation data. All produces the corresponding parameter to

each street intersection to distinguish the treatment . Each several cycles have carried

on a time of adjustment according to the system computed result to each region cyclical

length , namely cyclical adjustment. Each cycle carries on the assignment adjustment

according to the system computed result to each street intersection different green light

time , namely the green letter compares the adjustment. Each cycle starts the time

according to the system computed result to each street intersection cycle to carry on the

adjustment, namely phase adjustment.

ITACA is the intellectualised auto-adapted transportation control system ,this system by

the real-time control way work and can most greatly expand to more than 4500 street

intersections controls by center control level which is composed by a control server and

the client. The center control level installs ITACA software ,realizes the communication

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function ,the database handling dbh function , the software starts and software stops the

function .Through uses the auto-adapted traffic signal control system, may reduce the

transportation in the existing path to support stops up with the driving delays, reduces

the traffic accident, the formation rate and the mortality rate, simultaneously may cause

the energy the consumption reduction, and reduces the pollution degree.

4.4 Application

As example Currently there are 128 number of junctions that had been installed with

traffic signals in Putrajaya. There are junctions that are fully operated, while some were

operated in ‘Flashing Amber' and a few others are still under construction (ducting and

cabling works in progress). Refer Drawing1. An the latest news in Malaysia for greater

KL done by Special Task Force to Facilitate Business (Pemudah) said the initiatives

included enforcing the Towing of vehicles of traffic offenders and implementing traffic

monitoring Using Sydney’s Coordinated Area Traffic System (SCATS) and Intelligent

Traffic Adaptive Control Area (ITACA) to further enhance traffic flow. Is opposite to the

traditional system, the ITACA occupying of enhancement to Every 5 seconds on carry

on a time of collection and processing to the Transportation data. All produces the

corresponding parameter to each street intersection to distinguish the treatment. (In

system has each street Intersection in entire network accurate position, therefore

system all collects Information from each street intersection all neighbors street

intersection). Each several cycles on have carried on a time of adjustment according to

the System computed result to each stature region cyclical length, namely cyclical

Adjustment. Each cycle all carries on the assignment adjustment according to the

system Computed result to each street intersection different green light time, namely the

green letter compares the adjustment. Each cycle all starts the time According to the

system computed result to each street intersection cycle to carry on the adjustment

namely phase adjustment. May act according to the Transportation expert's experience,

carries on the optimization to the system. Under , will introduce the ITACA system from

following several aspects.

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First, system structure the systems control divides into three ranks: The first level is the

control center, it and the street intersection machine connect through the region

controller. The second level is region controller CMY. The third level is street

intersection controller RMY. The system structure following chart shows:

ITACA is the intellectualized auto-adapted transportation control system, this system by

the real-time control way work, and can most greatly expand to 4,800 street

intersections controls. Center control level the general center control level is composed

by a control server and the Client. The center control level installs ITACA software,

realizes the Communication function, the database handling dab function, the software

Start and software stops the function. Central computer system continuously with region

control machine maintenance communication, and then through region control machine

and street intersection machine maintenance communication. The region control

machine transmission and the receive data and the control command, the central

computer may in any time and the region control machine exchange information. ITACA

software gathers the Information involves:

The street intersection machine reports to the police starts to report to the police the

conclusion with the street intersection machine Street intersection machine active status

change The street intersection machine interior saves control form condition and

change situation The region control machine reports to the police starts to report to the

police the conclusion with the region control machine. Region control machine condition

change Vehicles detector condition and examination Data. When ITACA auto-adapted

pattern, the system inquires to the detector wheel with clear zero works every 5

seconds to carry on time To ITACA software may the manual start or the automatic

start. Under two methods, ITACA software all defers to the quite same not less than

step start. After ITACA software stops the movement, all street intersections machine

can automatically degrade to locally control the pattern, according to in advance the

local transportation control plan automatic movement which compiles in various street

intersections machine. After ITACA software restarts, can automatically succeed with

the central computer connected all equipment connects the system, before cannot

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because starts in ITACA software some equipment already add the electricity work but

to need them recto start. After ITACA software starts successfully, the entire

transportation control system will be able automatically local to control the pattern from

the street intersection machine to cut to the ITACA software control pattern, will

safeguard the entire transportation network to be at the optimizing control condition as

necessary.

4.5 Benefit

Has included the auto-adapted traffic signal control system in the existing new technical

method, it is the intelligent transportation control system core. Uses the benefit which

the advanced auto-adapted traffic signal control system produces to be most obvious.

Through uses the auto-adapted traffic signal control system, may reduce the

transportation in the existing path to support stops up with the driving delays, reduces

the traffic accident the formation rate and the mortality rate, simultaneously may cause

the energy the consumption reduction, reduces the pollution degree. Talent Traffic y

Transported (original Since Traffics) took is engaged in the transportation control for a

long time the well-known company and the Spanish Oviedo university cooperation, in

summarizes in the foundation Which the predecessor an experience, developed in 1990

has developed set of auto-adapted traffic signals control system ITACA (Intelligent

Traffic Adaptive Control of Areas ) the system. This system is based on the coil real-

time Collection data, in the computer module the simulation real-time Optimization

movement, and real-time issues the transportation control Command, achieves the best

transportation control effect the advanced system. The ITACA system in the world many

cities success movement, the Performance is outstanding, in domestic city and so on

Beijing, Wuhan has the Small scale application, in the near future also in other city

large-scale

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5-RONDO

5.1 Overview

RONDO (Rolling horizon based Dynamic Optimization of signal control) has been

developed that enables dynamic optimization of signal control parameters according to

traffic flow changes. A rolling-horizon algorithm is selected as an optimization method.

RONDO can apply to diverse traffic conditions from under-saturated to over-saturated.

RONDO also considers reducing traffic accidents. Some simulation tests have been

executed for the first step of evaluation of the system. Simulation experiments results

show that the system can manage unstable traffic flow well. It also shows the possible

application of the system.

5.2 RONDO Photos

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5.3 Features and Evaluations

RONDO has designed to optimize the signal timings of each signal every several

seconds according to the predicted cost expressed by the signal control performance

function with traffic efficiency indexes such as delay and stop number, which are

estimated based on the prediction of traffic flow changes in several minutes.

Consequently the signal timings are continuously updated. That enables RONDO to

manage the sudden changes of traffic flow.

RONDO control system has the following three features:

[1] Through terminal-terminal communication, oncoming traffic information is obtained

from signal controllers at upstream intersections; thereby the traffic flow approaching a

given intersection is predicted for time spans from the present to several minutes

ahead.

[2] Simulations are calculated for very short intervals for individual intelligent traffic

controllers to determine the optimal green time that minimizes vehicle delay (wait time

at stoplight).

[3] Two control modes are possible: a hybrid type in which signal control is performed in

coordination with central controller, and an autonomous type in which traffic signals

perform independently while coordinating with neighboring traffic controllers.

5.4 Application

Rondo uses a feedback loop to govern the behavior of traffic in the network core. It

manages the flows that originate and terminate between various PoPs (Points of

Presence) in the network by directing these flows into the multiple pathways that are

created using MPLS Label Switched Paths. These LSPs serve as conduits through the

network that are unaffected by the local optimization strategy of shortest path routing.

Rather, Rondo optimizes performance based on global traffic considerations in the

network.

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System Components

Rondo is composed of the major parts shown in Figure 2. In the remainder of this paper,

we will describe each element with emphasis on the data collection subsystem and the

analysis engine.

1) Physical Network

The experimental network is a set of 10 MPLS-enabled counters and Interconnections

patterned after a much-scaled down representation of a major Service provider’s

network backbone as depicted on their web site. We note that the provider has 2500

Pops worldwide so our model has only rough equivalence to reality. However, even with

only ten routers, our network exhibits complex and often fascinating behaviors. Routers

are connected with 10-megabit links, which makes possible the creation of realistic

overload Conditions. Each router models a Pop (Point of Presence) on the network

where customer nodes are attached. In Rondo, each node attached to a Pop is a PC

that sends and receives packets. The network uses a combination of Cisco® 3620 and

3640 series routers. The Release of Cisco’s IOS (Internet Operating System) available

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on our routers Allows only destination- based selection of MPLS tunnels. Upgrades will

ultimo- Cisco is a registered trademark of Cisco Systems, Inc. mutely allow selection

of the tunnels based on other parameters in the IP packet.

2) Programmable Load Generators and Loading Strategy

We use a collection of PCs programmed [1] to generate time-varying loads Similar to

those expected in an operational network. Background network Traffic on the network is

constant in time and is generated by commercially available packet generators. Loads

are carefully crafted to cause a buildup of Congestion that does not have an overall

steady state solution, and are designed to stress the given physical topology.

3) Data-Collection System

The data-collection system uses a variety of devices and techniques to monitor the

conditions in the network. These include both active and passive Methodologies that

capture such characteristics as throughput, loss, delay and jitter. Data collection, a key

part of Rondo, uses an extensible architecture to provide rapid processing of data under

time constraints for its collection, reduction and transmission. Data flow from the

network probes through the Collection system to the analysis engine with little latency

and to archival storage at a lower priority. Data are retained in a database system for

other Applications such as service-level management that do not require rapid data

Processing. We describe this part of the system in detail below.

4) Data Model and Database

Rondo uses the database for a variety of classes of information including Physical and

logical network topology, configuration information and archived measurement data.

The algorithms, displays and other components are driven by the information described

by this model, and as such, the Organization of this model is crucial to the effectiveness

of Rondo. The model, which is important for other applications, is realized in a relational

database. The most important function of the database is to hold the state of the

network topology, which changes as the system reroutes LSPs to alleviate congestion.

The analysis and reroute engine periodically updates the topology as the network is

reconfigured.

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5) Analysis and Rerouting Engine

This element of the system contains techniques for detecting congestion in a Network

and altering the existing traffic flows to eliminate an overload condition. The engine is

designed to focus on more than link utilization, which is the most basic metric of network

performance. Utilization indicates the level of activity between network elements and is

often viewed as a measure of network congestion. This view is too simple when one

considers the classes of traffic that flow over an IP network. High utilization of a link is

one form of congestion, but others might include excessive delay, jitter or high packet

loss, all of which could happen at relatively low levels of link utilization. These are

measures of congestion that seriously affect proposed services in Next-generation IP

networks, including voice and video. The engine is Designed use any measurable

quantity as an indication of a network problem That needs correction.

6) MPLS Configuration and Control

Rondo relies on MPLS to form explicit paths through the core network. Explicit paths

allow precise control over the placement of traffic flows within the routed domain of

Rondo. All traffic in Rondo flows through explicitly routed MPLS tunnels, which specify

each node along a path from the ingress to egress routers. The network configuration is

initially optimal in the sense that all tunnels travel via the shortest path in the network.

Once established, packets enter the MPLS tunnels as a function of their destination

address and are delivered to the egress router. Rondo thus uses MPLS as a

mechanism for packet forwarding that is not directly aware of quality of service. Mixing

packets with different levels of quality of service in an LSP is possible though but limits

the effectiveness of available controls. Once the initial explicit paths are established, the

analysis and reroute engine operates to reroute packets through a path established by a

new MPLS tunnel, which may no longer be the shortest path. This action currently takes

place via IOS commands that are issued from the controller. When MPLS traffic-

engineering MIBs become available, the controller will use SNMP to establish the new

routes.

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B. System Operation

The analysis and rerouting engine is in overall control of the system. The engine

communicates with the data collection system to establish a schedule of network

measurements. As the data collection system takes each measurement, it notifies the

analysis and rerouting engine of the presence of new data. The engine combines the

new data with the current system configuration and previous data to decide on the

appropriateness of rerouting an MPLS tunnel. If a move is appropriate, the analysis

engine reconfigures the network through the LSP configuration control and updates the

network state in the database. As we discuss in the following, the route of the new

MPLS tunnel does not necessarily preserve overall network optimality. Rather our goal

is to reroute traffic as quickly as possible to minimize the congestion at the expense of

achieving a theoretical optimum over the whole network. Global optimization might

imply moving many or even all the routes in the network. The strategy in Rondo is to

move from one to a few MPLS tunnels over a period of a few minutes with minimal

disruption to network traffic

6-UTOPIA

6.1 Overview

UTOPIA (Urban Traffic Optimization by Integrated Automation) / SPOT (System for

Priority and Optimization of Traffic) is the world’s most advanced adaptive traffic control

system and It ensures that optimal traffic control strategies are applied during all traffic .

UTOPIA-SPOT is an UTC system that produces co-ordination within an area without

neither a common nor a fixed cycle time for each intersection.

UTOPIA Spot helps to reduce congestion and traffic pollution in urban areas as it leads

to smoother flows of traffic even at peak times. UTOPIA Spot is installed in major cities

in Scandinavia, such as Oslo, Trondheim, Copenhagen and it is now used in several

cities in Italy and also in the Netherlands, USA, Norway, Finland and Denmark.

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UTOPIA Urban Traffic Control System offers a wide range of strategies designed to suit

any road network. In the fully adaptive mode, it constantly monitors and forecasts the

traffic status and optimizes the control strategy according to flow efficiency and/or

environmental criteria. This gives high performance even with unpredictable traffic

conditions.

6.2 UTOPIA Photos


UTOPIA/SPOT aims to minimize the total time lost by private vehicles during their trips,

subject to the constraint that public vehicles to be prioritized shall not be stopped at

signalized intersections. This is carried out by optimizing a cost function depending

upon various elements including: vehicle delays and stops, delays to public transport;

and deviation from the reference plan and previous signal settings. The optimization is

carried out at two levels: local and network. At the local level, the controller determines

the signal settings by optimizing a cost function adapted to the current intersection

traffic situation.

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Optimization is done on a ‘time horizon’ for the next 120 seconds and is repeated every

three seconds. At the network level, optimization is based on the cost function taking

account of the state of neighboring intersections to build dynamic signal co-ordination.

In UTOPIA/SPOT, bus priority is provided by shifting the ‘green window’ to match the

estimated arrival time of a bus at the stop line. This method uses bus location

information from well upstream of the junction and the signal timing is gradually adapted

to match the relevant green stage occurrence to the predicted arrival time of the bus.

This method has the potential advantage of a less abrupt impact on signal timings but

its efficiency is more dependent on accurate journey time forecasting. Information on all

vehicles is provided to the SPOT controllers by inductive loop vehicle detectors located

just downstream of the previous junction.

6.4 Application

The power of UTOPIA is prediction. UTOPIA estimates how the traffic Situation will

develop and calculates the best possible strategy. The ‘best Strategy’ is based on a so-

called ‘cost function’. The cost function weighs issues such as delay time, the number of

stops and specific priority Requirements. Taking into account the effect on adjacent

intersections, the Distributed control is optimized for each intersection in the network. All

intersections communicate the expected traffic flow to neighboring intersections,

allowing for a long prediction horizon.

6.5. Benefit

• Keeps the flow going?

• Manages timely public transport;

• Fully adaptive, adjusts to the traffic situation;

• Realizes strategic traffic policy objectives;

• Dynamic priority levels for public transport vehicles;

• Tuned and tested in lab situation before installation on-site;

• Open communication infrastructure