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    KA6423 P57600 Assignment 4 KA6423 P57600 Assignment 4 Document Transcript

    • Page 1 of 19 Intelligent Urban Transport Management System Assignment 4Name Muhammad bin RamlanMatrix No. P57600Subject KA 6423Session 2012/2013Lecturer Prof Ir Dr Riza Atiq O.K. Rahmat
    • Page 2 of 19QuestionYour hometown administrator wants to install an Urban Traffic Management System.You are given a task to evaluate the following systems:SCATsSCOOTITACAMAXBANDUTOPIA-SPOTBALANCERONDO (Rolling horizoN based Dynamic Optimization of signal)
    • Page 3 of 19Answer1. SCATsIntroductionIn 2010, As of December 2010, SCATS has been distributed to 145 cities in 24countries worldwide controlling more than 33,500 intersections.Aldridge TrafficControllers (ATC) are an RTA authorised Distributor of the world leading SCATS™Urban Traffic Management Control (UTMC) System.ATC have a large team ofSCATS™ Urban Traffic Management System qualified technical personnel tosupport customers in the design, deployment and implementation of the SCATS™system including the supply of its own Traffic Signal Controllers giving clients a totalsystem solution.The SCATS™ Urban Traffic Management System is a MS-Windows based softwaresolution that works in a tiered fashion via 1 or more Regional Controllers (RC) thatmeans traffic authorities are getting a highly redundant and therefore resilient systemfor maximum visibility and control of traffic.ATC have designed its latest generationof Traffic Signal Controller to be compatible with SCATS™ to provide trafficauthorities with a single supplier solution for complete Urban Traffic ManagementSystems.
    • Page 4 of 19ApplicationMost of Highway operator in Malaysia using SCATS to control their traffic lights inurban area. These very popular SCATS are an area wide traffic management systemthat operates under the Windows environment. It controls the cycle time, green splitsand offsets for traffic control intersections and mid-block pedestrian crossings. Withthe inclusion of vehicle detectors, it can adaptively modify these values to optimizethe operation to suit the prevailing traffic. Alternatively, it can manage intersections infixed-time mode where it can change plans by time of day, day of week. It isdesigned to coordinate traffic signals for networks or for arterial roads.Intersection connections to a regional traffic control computer can be permanent ormay be on-demand using dial-in or dial-out facilities. Each regional computer canmanage up to 250 intersections. A SCATS system can have up to 64 regionalcomputers.Monitoring is provided by a graphical user interface. Up to 100 users can connect toa SCATS central manager at the same time. Up to 30 users can connect to a singleregional computer simultaneously. Performance monitoring, alarm conditionnotification and data configuration facilities are included. SCATS automaticallycollect alarm and event information, operational and performance data and historicaldata. SCATS operate automatically but operation intervention is provided for use inemergencies.BenefitThe popular concept is that coordinating traffic signals is simply to provide green-wave progression whereby a motorist travelling along a road receives successivegreen signals. While this is one of the aims, the principal purpose of the controlsystem is to minimise overall stops and delay and, when traffic demand is at or nearthe capacity of the system, to maximise that capacity (throughput) and minimise thepossibility of traffic jams by controlling the formation of queues.Can be upgraded or expanded to meet changing requirements, other applicationscan be integrated into the system and provides details/reports of traffic flows forother planning purposes.SCATS enable a hierarchical system of fall back operationin the event of temporary communications failure. Such equipment faults aremonitored by the system
    • Page 5 of 192. ScootIntroductionSCOOT is the worlds leading adaptive traffic control system. It coordinates the aoperation of all the traffic signals in an area to give good progression t vehicles tothrough the network. Whilst coordinating all the signals, it responds intelligently andcontinuously as traffic flow changes and fluctuates throughout the day. It removesthe dependence of less sophisticated systems on signal plans, which have to beexpensively updated.
    • Page 6 of 19ApplicationInformation on the physical layout of the road network and how the traffic signalscontrol the individual traffic streams are stored in the SCOOT database. Anyadaptive traffic control system relies upon good detection of the current conditions inreal-time to allow a quick and effective response to any changes in the current trafficsituation.SCOOT detects vehicles at the start of each approach to every controlledintersection. It models the progression of the traffic from the detector through thestop 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 thenetwork delay.
    • Page 7 of 19The operation of the SCOOT model is summarized in the diagram above. SCOOTobtains information on traffic flows from detectors. As an adaptive system, SCOOTdepends on good traffic data so that it can respond to changes in flow. Detectors arenormally required on every link. Their location is important and they are usuallypositioned at the upstream end of the approach link. Inductive loops are normallyused, but other methods are also available.When vehicles pass the detector, SCOOT receives the information and converts thedata into its internal units and uses them to construct "Cyclic flow profiles" for eachlink. The sample profile shown in the diagram is color coded green and redaccording to the state of the traffic signals when the vehicles will arrive at the stopline at normal cruise speed. Vehicles are modeled down the link at cruise speed andjoin the back of the queue (if present). During the green, vehicles discharge from thestop line at the validated saturation flow rate.The data from the model is then used by SCOOT in three optimizers which arecontinuously adapting three key traffic control parameters - the amount of green foreach approach (Split), the time between adjacent signals (Offset) and the timeallowed for all approaches to a signaled intersection (Cycle time). These threeoptimizers are used to continuously adapt these parameters for all intersections inthe SCOOT controlled area, minimizing wasted green time at intersections andreducing stops and delays by synchronizing adjacent sets of signals. This meansthat signal timings evolve as the traffic situation changes without any of the harmfuldisruption caused by changing fixed time plans on more traditional urban trafficcontrol systems.BenefitThroughout its life SCOOT has been enhanced, particularly to offer an ever widerrange of traffic management tools. The traffic manager has many tools availablewithin 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 optimisation of the signal timings to minimise emissions and also provide estimations of harmful emissions within the controlled area
    • Page 8 of 193. ITACAIntroductionITACA - An Intelligent Traffic Area Control Agent. It has an Adaptive Subsystem thatoperates with a traffic model and produces Cycle Split and Offset times for acentralized area of traffic control. These times minimize delay and stops of trafficmoving in the area.ITACA provides real time urban traffic control by computing thebest solution for every intersection and continuously adapting signal sequences tomatch traffic demand.The ITACA Intelligent Adaptive Traffic Control System uses real time traffic flowdata, obtained from detectors located in the field, to model traffic line-ups at everystop line. It then continuously adjusts traffic signal parameters (cycle, split and offset)at every intersection in order to minimize the number of stops and delays throughoutthe street network within the ITACA systems control.The system produces small and frequent changes in traffic control parameters thatsmoothly adapt the traffic control plan to evolving changes in traffic demand. In thisway, the negative effects on the network that otherwise would be caused by planchanges - such as flow disturbances and time delays in re-establishing flow - areavoided.
    • Page 9 of 19ApplicationCurrently (as per 2011) there are 150 numbers of junctions that had been installedwith traffic signals in Putrajaya. There are junctions that are fully operated, whilesome were operated in ‘Flashing Amber and a few others are still under construction(ducting and cabling works in progress).An the latest news in Malaysia for greater KL done by Special Task Force toFacilitate Business (Pemudah) said the initiatives included enforcing the towing ofvehicles of traffic offenders and implementing traffic monitoring using SydneysCoordinated Area Traffic System (SCATS) and Intelligent Traffic Adaptive ControlArea (ITACA) to further enhance traffic flow.In opposite to the traditional system, the ITACA introduce enhancement to every 5seconds on carry on a time of collection and processing to the transportation data.All produces the corresponding parameter to each street intersection to distinguishthe treatment. (In system has each street intersection in entire network accurateposition, therefore system all collects information from each street intersection allneighbors street intersection). Each several cycles on have carried on a time ofadjustment according to the system computed result to each stature region cyclicallength, namely cyclical adjustment.Each cycle all carries on the assignment adjustment according to the systemcomputed result to each street intersection different green light time, namely thegreen letter compares the adjustment. Each cycle all starts the time according to thesystem computed result to each street intersection cycle to carry on the adjustmentnamely phase adjustment. It may act according to the transportation expertsexperience and carries on the optimization to the system. Under this condition, it willintroduce the ITACA system from following several aspects. Firstly, the systemstructure systems control divides into three ranks: The first level is the control center,it and the street intersection machine connects through the region controller. Thesecond level is region controller CMY. The third level is street intersection controllerRMY. The system structure following chart shows:ITACA is the intellectualized auto-adapted transportation control system, this systemby the real-time control way work, and can most greatly expand to 4,800 streetintersections controls.
    • Page 10 of 19Center 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 and function, the software start and software stops the function. The Central computer system is connected 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 stepstart. After ITACA software stops the movement, all street intersections machine canautomatically degrade to locally control the pattern, according to in advance the localtransportation control plan automatic movement which compiles in various streetintersections machine. After ITACA software restarts, it can automatically succeedwith the central computer connected all equipment connects the system, beforecannot because starts in ITACA software some equipment already add the electricitywork but to need them to restart. After ITACA software starts successfully, the entiretransportation control system will be able automatically local to control the patternfrom the street intersection machine to cut to the ITACA software control pattern, willsafeguard the entire transportation network to be at the optimizing control conditionas necessary.
    • Page 11 of 19BenefitHas included the auto-adapted traffic signal control system in the existing newtechnical method, it is the intelligent transportation control system core. It uses theauto-adapted traffic signal control system, may reduce the transportation in theexisting path to support stops up with the driving delays, reduces the traffic accidentthe formation rate and the mortality rate, simultaneously may cause the energy theconsumption reduction, reduces the pollution degree.TelventTráfico y Transporte (original SaincoTrafico) took is engaged in thetransportation control for a long time the well-known company and the SpanishOviedo university cooperation, in summarizes in the foundation which thepredecessor experiences, developed in 1990 has developed set of auto-adaptedtraffic signals control system ITACA (Intelligent Traffic Adaptive Control of Areas) thesystem. This system is based on the coil real-time collection data, in the computermodule the simulation real-time optimization movement, and real-time issues thetransportation control command, achieves the best transportation control effect theadvanced system. The ITACA system in the world many cities success movement,the performance is outstanding, in domestic city and so on Beijing, Wuhan has thesmall scale application, in the near future also in other city large-scale uses.
    • Page 12 of 194. MAXBANDIntroductionMaxband is a bandwidth optimization program that calculates signal timing plans onarterials and triangular networks. MAXBAND produce cycle lengths,offset, speedsand phased sequences to maximize a weighted sum of bandwidths. The primaryadvantage of MAXBAND is the freedom to provide a range for the cycle time andspeed. The lack of incorporated bus flows and limited field tests are disadvantagesof MAXBAND
    • Page 13 of 195. UTOPIA-SPOTIntroductionThe increasing traffic volume requires an integrated and balanced approach to trafficmanagement. The aim is to improve traffic over the whole area by minimizing traveltime for private traffic, while giving priority to public transport. In creating a better flowof vehicles, it leads to energy savings, a reduction of emissions and a welcomeincrease in safety. Urban Traffic Optimization by Integrated Automation (UTOPIA) iswidely regarded as one of the most advanced adaptive traffic signal control systemsavailable worldwide that has been successfully deployed in many places in Europe.UTOPIA operates on distributed intelligence. The processing capabilities atintersection level enable a swift response to the traffic volumes at the intersections.This makes UTOPIA ideal for flexible traffic control and priority to specific identifiedtraffic, like public service vehicles.ApplicationThe power of UTOPIA is prediction. UTOPIA estimates how the traffic situation willdevelop and calculates the best possible strategy. The ‘best strategy’ is based on aso-called ‘cost function’ method. The cost function weighs issues such as delay time,the number of stops and specific priority requirements. Taking into account the effecton adjacent intersections, the distributed control is optimised for each intersection inthe network. All intersections communicate the expected traffic flow to neighbouringintersections, allowing for a long prediction horizon. E
    • Page 14 of 19Benefit 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.
    • Page 15 of 196. BALANCETraffic Computer BaselBasel, the third-largest city in Switzerland, is an important European hub. Morethan 700.000 people live in the metropolitan area. Many enterprises are based inBasel, the city is a center for trade and culture and an intersection of the trafficroutes between Switzerland, Germany and France. Consequently, there is a lot oftraffic on Basels roads and the highways around the city.Basels traffic computer, however, was built in 1979. Its technology is out-of-date anddoes no longer meet todays demands. GEVAS software thus built up a new OCIT-compatible traffic center in Basel together with Bergauer AG. The new trafficcomputer communicates with the light signal systems via standardized OCITinterfaces. As well, remote recording of light signal states and remote supply of thecontrol units are possible. In addition, the new center is connected to a superordinatecontrol system, which is a central window to the electronically facilities of the Swissnational streets.Traffic-Adaptive Network Control BALANCEGEVAS-Roadshow in Düsseldorf, Berlin, Frankfurt and MunichIn a series of roadshows, GEVAS software presented traffic adaptive network controlBALANCE to experts and professionals from Germany and Austria. The events tookplace in Düsseldorf, Berlin, Frankfurt and Munich.Traffic-adaptive network control currently is a topic of many discussions in circles ofexperts. New model-based methods like BALANCE offer optimal Green Waves andare able to adapt signal programs to different traffic situations in an anticipatory way.The traffic flow is therefore improved significantly. It wanted to give first-handinformation on the potential of traffic-adaptive network control BALANCE and on howit can be integrated into existing systems. Out-of-date or overstrained signalprograms cause overall economic damage each day. With network control,constantly increasing traffic in metropolitan areas can be handled. Air pollution andtraffic noise are reduced as well. Theirpilot project in Hamburg and theimplementation of BALANCE in the TRAVOLUTION project in Ingolstadt havealready shown how good traffic-adaptive network control works in practice. It isimportant to stress that network control BALANCE can be integrated into existinginfrastructure without any problemand clearly reduces the users expenses.
    • Page 16 of 197. RONDOIntroductionFigure above shows a typical scenario that arises in Rondo when using destinationrouting based on finding the shortest path. Traffic from nodes A to C and from nodesB to C flows along a common set of network segments. With explicit routing throughMPLS tunnels, the data from node B to C can be rerouted to a longer but more lightlycongested path. The ability to monitor the global state of the network coupled withthe fine control afforded by MPLS makes congestion control possible in Rondo.ApplicationRondo uses a feedback loop to govern the behavior of traffic in the network core. Itmanages the flows that originate and terminate between various PoPs (Points ofPresence) in the network by directing these flows into the multiple pathways that arecreated using MPLS Label Switched Paths. These LSPs serve as conduits throughthe network that are unaffected by the local optimization strategy of shortest pathrouting. Rather, Rondo optimizes performance based on global traffic considerationsin the network.
    • Page 17 of 19System ComponentsRondo is composed of the major parts shown in Figure 2 above.In the remainder of this paper, we will describe each element with emphasis on thedata collection subsystem and the analysis engine.1) Physical NetworkThe experimental network is a set of 10 MPLS-enabled counters andinterconnections patterned after a much-scaleddown representation of a majorservice provider’s network backbone as depicted on their web site. We note that theprovider has 2500 PoPs worldwide so our model has only rough equivalence toreality. However, even with only ten routers, our network exhibits complex and oftenfascinating behaviors. Routers are connected with 10-megabit links, which makespossible the creation of realistic overloadconditions. 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. Therelease of Cisco’s IOS (Internet Operating System) available on our routers allowsonly destination - based selection of MPLS tunnels. -Cisco is a registered trademarkof Cisco Systems, Inc. Upgrades will ultimately allow selection of the tunnels basedon other parameters in the IP packet.2) Programmable Load Generators and Loading StrategyWe use a collection of PCs programmed to generate time-varying loads similar tothose expected in an operational network. Background network traffic on the network
    • Page 18 of 19is 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 anoverall steady state solution, and are designed to stress the given physical topology.3) Data-Collection SystemThe data-collection system uses a variety of devices and techniques to monitor theconditions in the network. These include both active and passive methodologies thatcapture such characteristics as throughput, loss, delay and jitter. Data collection, akey part of Rondo, uses an extensible architecture to provide rapid processing ofdata under time constraints for its collection, reduction and transmission. Data flowfrom the network probes through the collection system to the analysis engine withlittle latency and to archival storage at a lower priority. Data are retained in adatabase system for other applications such as service-level management that donot require rapid data processing. We describe this part of the system in detailbelow.4) Data Model and DatabaseRondo uses the database for a variety of classes of information including physicaland logical network topology, configuration information and archived measurementdata. The algorithms, displays and other components are driven by the informationdescribed by this model, and as such, the organization of this model is crucial to theeffectiveness of Rondo. The model, which is important for other applications, isrealized in a relational database. The most important function of the database is tohold the state of the network topology, which changes as the system reroutes LSPsto alleviate congestion. The analysis and reroute engine periodically updates thetopology as the network is reconfigured.5) Analysis and Rerouting EngineThis element of the system contains techniques for detecting congestion in anetwork and altering the existing traffic flows to eliminate an overload condition. Theengine is designed to focus on more than link utilization, which is the most basicmetric of network performance. Utilization indicates the level of activity betweennetwork elements and is often viewed as a measure of network congestion. Thisview is too simple when one considers the classes of traffic that flow over an IPnetwork. High utilization of a link is one form of congestion, but others might includeexcessive delay, jitter or high packet loss, all of which could happen at relatively lowlevels of link utilization. These are measures of congestion that seriously affectproposed services in next-generation IP networks, including voice and video. Theengine is designed use any measurable quantity as an indication of a networkproblem that needs correction.6) MPLS Configuration and ControlRondo relies on MPLS to form explicit paths through the core network. Explicit pathsallow precise control over the placement of traffic flows within the routed domain of
    • Page 19 of 19Rondo. All traffic in Rondo flows through explicitly routed MPLS tunnels, whichspecify each node along a path from the ingress to egress routers. The networkconfiguration is initially optimal in the sense that all tunnels travel via the shortestpath in the network. Once established, packets enter the MPLS tunnels as a functionof their destination address and are delivered to the egress router.Rondo thus uses MPLS as a mechanism for packet forwarding that is not directlyaware of quality of service. Mixing packets with different levels of quality of service inan LSP is possible though but limits the effectiveness of available controls. Once theinitial explicit paths are established, the analysis and reroute engine operates toreroute packets through a path established by a new MPLS tunnel, which may nolonger be the shortest path. This action currently takes place via IOS commands thatare issued from the controller. When MPLS traffic-engineering MIBs becomeavailable, the controller will use SNMP to establish the new routes.System OperationThe analysis and rerouting engine is in overall control of the system. The enginecommunicates with the data collection system to establish a schedule of networkmeasurements. As the data collection system takes each measurement, it notifiesthe analysis and rerouting engine of the presence of new data. The engine combinesthe new data with the current system configuration and previous data to decide onthe appropriateness of rerouting an MPLS tunnel. If a move is appropriate, theanalysis engine reconfigures the network through the LSP configuration control andupdates the network state in the database.As we discuss in the following, the route of the new MPLS tunnel does notnecessarily preserve overall network optimality. Rather our goal is to reroute trafficas quickly as possible to minimize the congestion at the expense of achieving atheoretical optimum over the whole network. Global optimization might imply movingmany or even all the routes in the network. The strategy in Rondo is to move fromone to a few MPLS tunnels over a period of a few minutes with minimal disruption tonetwork traffic.