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Transcript of 4 Interrupted flow HCM 2010 - ТФБ · PDF file16.4.2015 1 Traffic engineering Highway...

  • 16.4.2015

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    TrafficengineeringHighwayCapacityManual

    2010Interruptedtrafficflow

    Dr.DragoSever

    2

    Content

    Interruptedtrafficflow Intersections TwowaySTOPcontrolledintersections(TWSC) Roundabouts Signalizedintersection

    Examples urbanstreets (HCS2010)

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    OrganizationofHCMHCM2010

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    Volume1 ConceptsVolume2 UninterruptedFlowFacilities

    Freeways,ruralhighways,ruralroadsVolume3 InterruptedFlowFacilities

    Urbanarterials,intersections,roundaboutsSignalsatfreewayinterchanges,BicycleandPedestrianpaths

    Volume4 SupplementalMaterials(Website)http://www.hcm.trb.org

    NEW

    Urbanstreetsegmentsandfacilities Chapter16:Urbanstreetfacilities Chapter17:Urbanstreetsegments

    Intersections Chapter18:Signalizedintersection Chapter19:TWSCintersection Chapter20:AWSCintersection Chapter21:Roundabouts Chapter22:Interchangerampterminal

    Offstreetpedestriananbicyclefacilities Chapter23:OffstreetP&Bfacilities

    Volume3:InterruptedflowHCM2010

    4

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    HCM2010 TWSCintersections

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    TWSCintersections(Ch.19)

    Limitations:isolatednotrafficlightsintersectionwithoutaffectingadjacentintersectionsatadistanceofatleast400m

    HCM2010 TWSCintersections Theory

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    Gapacceptance Availabilityandusefulnessofgaps Relativepriorityofvariousmovementsattheintersection Measuresare: CriticalHeadway theminimumtimeintervalinthemajorstreettraffic

    streamthatallowsintersectionentryforoneminorstreetvehicle

    FollowupHeadway timebetweenthedepartureofonevehiclefromtheminorstreetandthedepartureofthenextvehicleusingthesamemajorstreetheadway

    Movementsofdifferenttrafficflowsattheintersection

    NEW

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    HCM2010 TWSCintersections

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    PriorityofwayRank1: throughandrightturnonMAS

    andpedestrianthroughMISRank2: leftandUon MASandrightfrom

    MISonMAS,pedestriansMASRank3: throughonMIS(+)andlefton

    MIS(T)Rank4: leftonMIS(+)

    MAS

    MIS

    MAS Major streetMIS Minor street

    NEW

    HCM2010 TWSCintersections

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    LOScriteria

    Automobiles

    Pedestrians

    BicyclemodeiscurrentlybeingpreparedbyHCM.

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    HCM2010 TWSCintersections Methodology(automobile)

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    NO

    YES

    1. Determine and label movement priorities

    2. Convert movement demand volumes to flow rates

    3. Determine conflicting flow rates

    4. Determine critical headways and follow-up headways

    Coordinated upstream signal present

    5b. Compute potential capacities adj. for effects of upstream signals

    5a. Compute potential capacities Chapter 17

    Next steps

    NEW

    HCM2010 TWSCintersections Methodology(automobile)

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    9. Compute Rank 4 movement capacities

    10. Final capacity adjustments

    11. Compute movement control delay

    12. Compute approach and intersection control delay (LOS)

    13. Compute 95th percentile queue lengths

    8. Compute Rank 3 movement capacities

    7. Compute Rank 2 movement capacities

    6. Compute Rank 1 movement capacities

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    HCM2010 TWSCintersections

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    3.Det.theconflictionflowratesRank4 movements7and10 leftfromMIS

    Phase I:

    Phase II:

    (veh/h)

    HCM2010 TWSCintersections

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    4.Criticalheadway x,ct

    Adjustmentfactors: forheavyvehicles

    1 1onelaneineachdirectionMAS2 2ormoreineachdirectionMAS

    forgrade0,1 movements9,120,2 movements7,8,10,11

    forgeometry0,7 leftturninthreelegintersection0,0 other

    (s)

    NEW

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    HCM2010 TWSCintersections

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    4.FollowupHeadway

    Adjustmentfactor: forheavyvehicles(s):

    0,9 1onelaneineachdirectionMAS1,0 2twoorthreelanesineachdirectionMAS

    (s)

    x,ft

    HCM2010 TWSCintersections

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    5.Computepotentialcap.ifnoupstreamsignaleffectsarepresent

    (veh/h)

    for each movement

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    (veh/h)

    HCM2010 TWSCintersections

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    6. 9.Computemovementcap.Rank2: LeftonMAS,rightonMIS: Other: Specialcase:

    (veh/h)

    (veh/h)

    HCM2010 TWSCintersections

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    10.Finalcap.adjustment Shared capacity on MIS approaches

    Compute flared MIS lanes effects

    (veh/h)

    (veh/h)

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    HCM2010 TWSCintersections

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    11.Computemov.controldelay

    (T=0,25 for 15 min)

    Rank 1:

    Rank 2 4:

    (s/veh)

    HCM2010 TWSCintersections

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    13.ComputeQueueLengths

    (veh)

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    HCM2010 TWSCintersections PedestrianMethology

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    1. Identify two stage crossing(raised pedestrian median island)

    2. Determine Critical Headway

    3. Estimate probability of a delayed crossing

    4. Calculate average delay to wait for adequate gap

    5. Estimate delay reduction due to yielding vehicles

    6. Calculate average pedestrian delay and determine LOS

    HCM2010 TWSCintersections Pedestrian

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    2.Determinecriticalheadway1 ft = 0,304 m- Single pedestrian

    (s)

    - Group of pedestrians

    spatial distribution of pedestrians (pedestrian)

    field observation: platoon size

    (s)

    (pedestrian)

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    HCM2010 TWSCintersections Pedestrian

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    3.Estimateprob.ofdelayedcrossing

    4.Calculate averagedelay

    Probability of a blocked lane

    Probability of a delayed crossing

    (s)

    Average pedestrian gap delay

    No vehicle STOP

    Average gap delay for pedestrian who incur nonzero delay

    (s)

    HCM2010 TWSCintersections Bicycles

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    NomethodologyspecifictobicyclisthasbeendevelopedBicyclistmaytraveleitherasamotorvehicleorapedestrianCriticalheadwaydistributionshavebeenidentifiedintheresearchforthebicyclecrossingtwolaneMSMultiplebicyclistoftenusethesamegapinthevehiculartrafficstream.

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    UsingHCS2010

    HCM2010 Roundabouts

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    Roundabouts(Ch.21)

    Intersection withgeneralcircularshape,characterizedbyyieldonentryandcounterclockwisecirculationaroundacentralisland.

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    HCM2010 Roundabout Theoreticalbasis

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    Flowsrequiredforanalysis: Entryflowrates, Conflictingflowrate Exitflowrate

    (pc/h)

    tfcriticalheadwaytcfollowupheadway

    NEW

    HCM2010 Roundabout Methodology Automobile

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    1. Convert movement demand volumes to flow rates

    2. Adjust flow rates for heavy vehicles

    3. Determine circulating and exiting flow rates

    5. Determine the capacity of each entry lane and bypass lane (pc/ln)

    6. Determine pedestrian impedance to vehicles

    4. Determine entry flow rates by lane

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    HCM2010 Roundabout Methodology Automobile

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    9. Compute the average control delay for each lane

    10. Determine LOS for each lane on each approach

    11. Compute control delay and determine LOS for each approach and the roundabout

    12. Compute 95th percentile queues for each lane

    8. Compute v/C ratio for each lane

    7. Convert lane flow rates and capacities into veh/h

    HCM2010 Roundabout

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    3.Determinecirculationflowrate

    (pc/h)

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    HCM2010 Roundabout

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    3.Determineexitflowrate

    (pc/h)

    HCM2010 Roundabout

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    4.Determineentryflowsforlanes

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    HCM2010 Roundabout Theoreticalbasis

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    (pc/h)

    5.Determinethecapacity

    HCM2010 Roundabout

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    2entrylanes 1circ.lane

    (pc/h)

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    HCM2010 Roundabout

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    1 entrylanes 2 circ.lane

    (pc/h)

    HCM2010 Roundabout

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    2 entrylanes 2 circ.lane

    (pc/h)

    (pc/h)

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    HCM2010 Roundabout

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    YieldingbypasslaneTerminatesatahighangleyieldingtoexitingtraffic

    Capacityapproximatedusingtheappropriatesingle lane(1x1)ormultilane(1x2)capacityformula

    Treattheexitingflowfromtheroundaboutastheconflictingflow

    (pc/h)

    HCM2010 Roundabout

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    NonyieldingbypasslaneMergesatalowanglewithexitingtrafficorformsanewlaneadjacenttoexitingtraffic

    Capacity isexpectedtoberelativelyhighduetoamergingoperationbetweentwotrafficstreamsatsimilarspeeds.

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    HCM2010 Roundabout

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    6.Pedestrianimpedancetovehicles

    For 1 lane entry:

    HCM2010 Roundabout

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    6.Pedestrianimpedancetovehicles

    Estimation for 2 lane entry:

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    HCM2010 Roundabout

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    7.Convertlaneflowratesintoveh/h

    (veh/h) (veh/h)

    heavy vehicleadjustmentfactor

    HCM2010 Roundabout

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    8.,9.v/Candcomputeaveragedelay

    (s/veh)

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    HCM2010 Roundabout

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    11.DelayandLOS approach,int.

    (s/veh)

    (s/veh)

    HCM2010 Roundabout

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    12.Queueslengthforeachlane

    (voz)

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    HCM2010 Roundabout

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    UsingHCS2010

    HCM2010 Signalizedintersections

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    Signalizedintersections(Ch.18)

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    HCM2010 Signalizedintersection Theoreticalbasis

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    Analysisboundaries

    1500 m

    1000 m

    300 m

    40 60 90 km/h

    Methodologyisvalidforisolatedsignalizedintersections.

    HCM2010 Signalizedintersection Theoreticalbasis

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    Drivingthroughsem.intersection

    Operational stateoftrafficisdefinedby: Volumesand flowra