Transportation operation and management review英文Word文档下载推荐.docx
《Transportation operation and management review英文Word文档下载推荐.docx》由会员分享,可在线阅读,更多相关《Transportation operation and management review英文Word文档下载推荐.docx(18页珍藏版)》请在冰点文库上搜索。
minimizecongestion(anditssideeffects),improvesafety,enhanceoverallmobility,andprovidesupporttootheragenciesduringemergencies.
5、ITS定义
IntelligentTransportationSystem(ITS)improvestransportationsafetyandmobilitythroughtheuseofadvancedinformationandcommunicationstechnologies.
6、ITS系统workflow
Architecture:
Theframeworkthatlogicallyconnectsthesystemelementstomeetrequirements.ForITS,thearchitecturewillintegratetheuserservices,allocatetheirsystemrequirementstophysicalelements,anddefinetheirinterconnections.Earlyresearchandtestsprovideinformationnecessarytodevelopanarchitecture.
Standards:
thearchitecturewillidentifyareaswherestandardsandprotocolsareneeded.Somewillalreadybedefined,otherswillbedevelopedthroughthevoluntarystandards-settingprocess.
7、TrafficParameters
TimeHeadway:
Theelapsedtimebetweenthepassageofanidenticalobservationpointbyconsecutivevehiclesinthetrafficstream.
Volume:
Generallyexpressedintermsofflowrate--Atemporalquantitymeasuredefinedasthenumberofvehiclespassingapointinagivenperiodoftime,usually1hour--Flowrateistheinverseoftheaverageofthetimeheadwaysmeasuredoverthesameperiodsuchthatq=3600/h
q=hourlyflowrate(vehiclesperhour),h=averagetimeheadway(secondspervehicle),and3600=numberofsecondsperhour.
Density:
thenumberofvehiclesoccupyingagivenamountofroadwayspace(generallyalane–mile).
Occupancy:
thepercentoftimethedetectionzoneofadetectorisoccupiedbysomevehicle.
Distanceheadway:
thedistancebetweenidenticalpointsonconsecutivevehiclesinsinglefile.
Demand:
theamountoftrafficvolume(orflowrate)thatoccursonafacilityundersomegivensetoftravelconditions.
Capacity:
Atrafficfacility’sabilitytoaccommodateamovingstreamofpeopleorvehiclesinagiventimeperiod.
Throughput:
Thevehicle–milesoftravelcarriedbyagivenlengthofroadwayforagivenperiodoftime.
SpotSpeed:
Thespeedofanindividualvehicleasitpassesanobservationpointofthetrafficstream.
Timemeanspeed:
Thearithmeticmeanofindividualspotspeedsthatarerecordedforvehiclespassinganobservationpointoveraselectedtimeperiod.
SpaceMeanSpeed:
Theaveragespeedofallvehiclesoveraknownlengthofhighwayataparticulartime.(Harmonicmeanofindividualvehiclespeeds)
8、车头时距Timeheadway
9、如何收集spotspeed
Usingaspeedtrapstation,apairofdetectorsisplacedonalengthofroadway.Speediscalculatedfromthetimeittakesvehiclestotransversethedistancebetweenthestartofthedetectionzonesofthetwodetectors.
Instantaneousspeedsofindividualvehiclescanbedeterminedfromtheslopeofthevehicletracesonaspace–timediagram.
10、Timemeanspeed
Anadequatelysizedsampleofspotspeedsisneededtoensurethatthetimemeanspeedapproximatesthepopulationmeantowithinthedesiredaccuracy(atleast50andpreferably100vehicles).
11、SpaceMeanSpeed
12、延误的分类
Delaymeasuresareusedforfreewaysandsignalizedintersectionstoevaluatethebenefitsofoperationalimprovementsandtoestimatecost-effectiveness
StoppedDelay:
Thesumofthestoppedtimes.
ApproachDelay:
thetotaltimerequiredtotraversetheapproachsectionunderstudy.Itisequaltotheapproachtimelessthetimerequiredforanunimpededvehicletotravelthroughthesamesectionunderfree-flowconditions.
TimeinQueueDelay:
thesumofstoppedtime,motiontime,andexittime.Itisequivalenttothetotalapproachtimeminusthejoiningtime.
13、Time-SpaceDiagramforDelayMeasures
14、单位换算
1mile=1.61kilometers,1feet=0.3048meters,1mile=5280feet
1mileperhour(mph)=1.47feetpersecond(fps)
15、TrafficSurveillanceandDataDetection为什么重要?
它可以应用于许多方面:
trafficmanagement,rampmetering,signalcontrol,freewaymonitoring,accidentdetection,parkingguidance,trafficguidance
16、各种信息采集技术
Inductiveloop
采集的数据
advantages
weakness
Count
Largeexperiencebase
Installationrequirespavementcut
Speed
Mature,wellunderstood
Improperinstallationdecreasespavementlife
Occupancy
Insensitivetoinclementweather
Wireloopssubjecttostressesoftrafficandtemperature
MicrowaveRadar
TrafficVolume
Typicallyinsensitivetoinclementweatherattherelativelyshortrangesencounteredintrafficmanagementapplication
ContinuouswaveDopplersensorscannotdetectstoppedvehicles
Directmeasurementofspeed
Multiplelaneoperationavailable
InfraredSensors
Transmitsmultiplebeamsforaccuratemeasurementofvehicleposition,speedandclass
Operationmaybeaffectedbyfogwhenvisibilityislessthan(约等于)20feetorblowingsnowispresent
Length,
Multiplelaneoperationavailable
Installationandmaintenance,includingperiodiclenscleaning,requirelaneclosure
Vehicleclassification
Multizonepassivesensorsmeasurespeed
Passivesensormayhavereducedvehiclesensitivityinheavyrain
UltrasonicDetector
count
Environmentalconditionssuchastemperaturechangeandextremeairturbulencecanaffectperformance
presence
Capableofoverheightvehicledetection
Largepulserepetitionperiodsmaydegradeoccupancymeasurementonfreewayswithvehiclestravelingatmoderatetohighspeeds
LargeJapaneseexperiencebase
VideoImageProcessors
volume
Monitorsmultiplelanesandmultipledetectionzones
Installationandmaintenancerequirelaneclosure
density
Easytoaddandmodifydetectionzones
Performanceaffectedbyinclementweather
incidentdetection
Richarrayofdataavailable
Reliablenighttimesignalactuationrequiresstreetlighting
17、Comparison(Fixedtrafficdetectors)
Volume
QueueLength
VehicleClass
Others
Loops
✔
○
Magnetics
Microwave
timeheadway
Ultrasonic
✘
Congestiontime
Infrared
Video
headway,incident
18、RawData的问题
Fromdifferentsensors(differentformats),multipletypes(numbers,text,video,image)
Toocomplicatedtobeunderstood
19、数据处理流程
20、DataScreening的主要任务
Identifysuspectorerroneousdatavalues,Identifymissingvalues,Identifyinaccuratedatavalues
21、Howtoidentifysuspectorerroneousdata?
Thresholdvalues,Trafficflowtheory-basedapproach,OtherQualitycheck,Clusteranalysis
22、
(1)Maximumvolumethreshold
Usedtodetectvolumesthatareinfeasiblebasedonexpectedhighwaycapacity.Forexample,17for20secondvolumes,25for30secondvolumes,250for5minvolumes,3000pvphplforanytimeperiodlength
23、
(2)Averageeffectivevehiclelength
Forexample,minimumvehiclelength:
9ft;
Maximumvehiclelength:
60ft.
24、(3)Maximumspeed
Empiricalevidencesuggeststhatactualspeedvaluesathighspeedlevelsareoftensuspected(e.g.,greaterthan80mphfor5minutes)
25、(4)Minimumspeed
Empiricalevidencesuggeststhatactualspeedvaluesatlowspeedlevelsaresometimesinaccurate(e.g.,lessthan3mph)
26、Datamissing
Causeofmissingdata
SpatialAttributes
TemporalAttributes
Constructionactivitythatdisruptsthetrafficmonitoringinstallation
Datamissingatasinglelocationorseveralconsecutivelocationsalongacorridor
Datamissingforextendedperiodoftime(i.e.severalmonths)
Failureoftrafficdetectors
Datamissingatasingleorseveralisolatedlocations
Datamissingforshortorlongperiodsoftime(i.e.severalminutestoseveralweeks)
DisruptionofcommunicationsbetweenfieldcontrollersandTMC
Datamissingforshortperiodsoftime(i.e.lessthanseveralminutes)
FailureofTMCordataarchivingsystemfailure
Datamissingatalllocations
Datatypicallymissingforshortperiodsoftime(severalhourstolessthanoneday)
27、DataFusion
28、DataMining
1)Anomalydetection
(Outlier/change/deviationdetection)–Theidentificationofunusualdatarecords,thatmightbeinterestingordataerrorsthatrequirefurtherinvestigation.
应用:
BeforeusingGPSdatatopredictbusarrivaltime,weneedidentifythenoisepoints.
2)Associationrulelearning
(Dependencymodelling)–Searchesforrelationshipsbetweenvariables.
Finddependencyandcorrelationamongvariousfactorsinaccidentresearch.Forexample,alcoholdrinkingmayhavedifferentimpactsoncrashrisk,dependingondrivergenderandage
3)Clustering
–isthetaskofdiscoveringgroupsandstructur