D2E Fe Calibration-SIMModels Ppt

8/13/2019 D2E Fe Calibration-SIMModels Ppt

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PTV Planung Transport Verkehr AG

76131 Karlsruhe

www.ptv.de

Abbildung/Foto

zum Projekt

Calibration ofVISSIM14th ptv vision User Group Meeting

Martin Fellendorf


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Fellendorf: VISSIM calibration; ptv vision UGM Oct 2004

Definition

> VerificationProcess of the software developer to assure the correctness of thesoftware implementation (the software should comply with the

specification and user manual)-> should be OK with potential of improvement in 4.0, service packs

> ValidationProcess of model developer to adjust model in order to match traffic

characteristics observed in the field in general (ex. Modeling oftactical lane changing maneouvers)-> PTV cooperation with research institutions; NGSIM participation

> Calibration

Process of software user to adjust model parameters in order toreproduce local driver behaviour and meet local field data (ex. Doesmodel match with measured discharge rates at traffic lights)-> user has to adjust behavioural parameters to match local

conditions; focus of this presentation

Workflow Simulation Calibration general Motorways Mixed traffic Urban Summary


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Objective of the study will effect workflow

Top Down

> Objective: overall volumes and travel times

> Method: calibrate VISUM model with one/several ODs;refine VISUM network including network topology andadjust hourly OD matricesexport VISSIM network and refine topology

> Application: Large scale feasibility studies with complex routing(> 10-20 intersections and alternative routes)

Bottom UP

> Objective: detailed operation with system performance ranking 2nd> Method: VISSIM model from scratch:

definition of network topology based on arials/CADdefinition of routes and/or DTA with multiple ODs

calibration of VISSIM parameters and input data> Application: detailed feasibility studies and traffic operations



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Tasks of simulation study: model setup

1. Scope of project

> Define project objective

> Identify area of investigation and are of influence> Select approach (top-down vs. bottom-up); actuated y/n

> Estimate resources

2. Data collection

> Traffic volumes (counts and/or O/D-matrices)

> Base maps, airials, CAD, GIS

> Traffic control (signals, VMS,...)

> Field observations (counts, speeds, gap times)

3. Coding of base model

4. Error checking

> Review animation (deadlocks, lane changing,...)> Check volumes and speed during simulation (use counters+VAP)



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Tasks of simulation study: calibration and application

4a.Capacity calibration, test simulation MOEs against field data:

> calibration of discharge rate at signals

> Link and lane speeds and volumes; flow-speed curves4b. Capacity calibration by generation of congestion

> No queues&congestion at areas or links where it is not observed

> Increase capacity at those bottlenecks by adding lanes or speed

> Estimate capacity by increasing flow rate in intervals of 5-15min

4c. Route choice calibration

> If dynamic assignment check sensibility of paths

> Floating Car Data; licence plate counting -> costly, rarely done

5. Result: Calibrated base case ,

then Test alternative scenarios



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Statistics used for calibration

> GEH index (UK) to test observed vs simulated link volumes

satisfactorily calibrated ifGEH < 5 for 85% of the links and

GEH < 4 for sum of all link counts

> Route Mean Square (RMS) to test flow rate / discharge rate

with Nsimulation runs with varying random seed;

change random seed and parameter sets -> VBA application

try to minimize RMS by parameter variation

SimValObsVal

SimValObsVal

GEH +

=

)(2

)(1 ObsValSimValN

RMS

n

=



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Calibration of VISSIM

Traffic volumes: important parameters

> Total link and turning volumes

> Path flows match Origin-Destination pairs and trip length distribution> Distribution of vehicles types (Composition)

Vehicle and driver types:

> Technical abilities of vehicles (check trucks, buses, trams)

> Associate driver behaviourvia link types and vehicle classes

> Desired speed distribution per link and vehicle type> Mean value (max throughput at 60 90 km/h)

> Increase capacity by decreasing variability of desired speedNetwork

> Type of signalization

> Gap times at unsignalized intersections (priority rules)> Visibility distance (Lane change at connectors)Workflow Simulation Calibration general Motorways Mixed traffic Urban Summary


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Network calibration: visibility distance

> Connectors Lane Change = visibility

> Visibility of connector 3 than 500m

> Problem for CarPurple as visibility < 500m

1

2

3

Calibration general

500 m

Workflow Simulation Motorways Mixed traffic Urban Summary


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CC-Parameters influence capacity of motorway

VISSIM 3.70

2 lane motorway

only left lane investigated

5% trucks (non-overtaking)

DesSpeed Car

110-140 km/h

SimDuration 3*4500s

VolumeIncrease every 300s by

200 veh/h

All CC default motorway except:

CC1: 0,9s Following distance

CC7: 0,4 m/s OscillationAccel.

CC1: 1,5s Following distance

CC7: 0,2 m/s OscillationAccel

0

20

40

60

80

100

120

140

0 500 1000 1500 2000 2500

Volume [veh/h/lane]

spe

ed

[km/h]



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Awareness on motorways

Typical values:

Duration: 1s 4s

Probability: 1% - 3%

(%: wrong unit for probability in 4.00)



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Capacity as function of awarenes

Conclusion: for motorways (W99) some Vissim-drivers are sleeping

VISSIM 4.00-11

3 lane motorway

0% trucks

DesSpeed110-120 km/h

SimDuration 6900s

VolumeIncrease every

300s by 100 veh/h

No breakdown with

0% sleepers



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Weaving sections on motorways

Calibration general Motorways Mixed traffic Urban Summary

> The closer the weavingvehicles comes to theend of the merging

zone, the more likelyhe will force the trailingvehicle on the majorlane to slow down

> Reduced capacity atAcceptDecel (trail) >0.75

Workflow Simulation


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Gradients on motorwayBrilon; Breler: Traffic Flow on Freeway Upgrades, TRB 2004

> Study conducted for the HBS(German HCM) by RuhrUniversity

> Field measurements at 5 sectionsof German Motorways

> VISSIM was enhanced bygradient dependent acceleration

> Simulated data fits fieldmeasurements

> Example: A8, 2 lanes, grade

5.6%, speed limit 100 km/h, notruck passing, truck rate 17%

Urban SummaryWorkflow Simulation Calibration general Motorways Mixed traffic


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Gradients on motorwayBrilon; Breler: Traffic Flow on Freeway Upgrades, TRB 2004

Urban Summary

> After calibration simulation modelwas employed for varying

> gradient,

> number of lanes> Volumes

> Truck percentage

> Generate capacity curves forHBS

> Example:top: avg. Speed in 5min intervals

over 2km on 3-lane upgrade with20% trucks

bottom:Capacities for 1h intervals

Workflow Simulation Calibration general Motorways Mixed traffic


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Calibration and mixed traffic comparison of animation

VISSIM models shared lane

> Several vehicle typesshare a lane; multiple

lanes; regular vehicles onlyone per lane-> bicyclist passed by car

> One single oversized lane

with multiple regularvehicles parallel-> regular vehicles parallelon a single lane

Calibration:

> Count vehicles per space

> Lateral distance as f(v)

Urban Summary

Hossain: Calibration of the Microscopic

Traffic Flow Simulation Model VISSIM for

Urban Conditions in Dhaka City; MsC KA 2004

Workflow Simulation Calibration general Motorways Mixed traffic


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Calibration and mixed traffic

> Vehicle position within lane and observation of adjacent lanes-> validation and calibration

> Lateral distance between vehicles as function of speed difference-> calibration

> More experience needed in countries with little lane discipline

s > s0 at v=0

s > s1 at v=50



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Comparison of Simulation and HCM

> TRB subcommitteeHCQS compared in2002 results of various

microsimulators withHCM results

> Each developerreceived artificial but

realistic input data andperformed simulationfor base and futurecase

> Developer calibratedhis own model

> HCQS membersstandarized and

compared results

Mixed traffic Urban SummaryWorkflow Simulation Calibration general Motorways


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Comparison of Simulation and HCM

Problem in task description

> Link counts given

> O/D unknown> Assumption on paths

> Results like VMT or VHTdepend on paths flows

Results of Comparison

> 13% diff of speeds in baseyear but 69% for future

> Calibration is important> Diff. in congestion modeling

> Diff. assumption on O/Ds-> same as in real world

..\Examples\Training\HCM2002 ??


F ll d f VISSIM lib ti t i i UGM O t 2004


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Calibration of urban roads

> Lane allocation-> trick: vehicle class specific dummy connectors

> Discharge rate at signals

Look-ahead distance for blue left

turning vehicles

Look-ahead distance for green

left turning vehicles


F ll d f VISSIM lib ti t i i UGM O t 2004


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Discharge rate at signalized junctions (manual 10.20)

Edit *.INP-FileEvaluation Type DISCHARGE SCJ 1 SIGNAL_GROUP 2

COLLECTION_POINT1 TIME FROM 0.0 UNITL 99999.0

For each measurement a separate file *.a00; *.a01; *.a02; .....

Evaluation table

Discharge at SCJ 1, Signal group 2 (measurement 1)31 0.85 2.58 1.61 1.61 1.59 ... 1.48 (16: 1.77) 1.57 1.54

91 0.97 2.42 2.21 1.92 1.71 ... 1.31 (16: 1.73) 2.01 1.64

...

1651 1.02 2.33 1.86 1.87 1.71 ...

----- 1 2 3 4 5 ... 17 18 19 20 21

----- 0.95 2.43 2.02 1.85 1.73 ... 1.64 1.80 1.65 1.87 1.04

----- 28 28 28 28 28 ... 27 25 16 6 2

[496: 1.74]Workflow Simulation Calibration general Motorways Mixed traffic Urban Summary



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References

Material borrowed without mentioning source at all ocurrences

> Dowling Associates; Cambridge Systematics: Volume III Guidelines forApplying Traffic Microsimulation Modeling Software; prepared for FHWA,

August 2003 www.ptvamerica.com/library

Further references

> Bloomberg, L.; Swenson, M.; Haldors, B.: Comparison of Simulation Modelsand the Highway Capacity Manual, Preprint, Annual Meeting Transportation

Research Board, Washington, D.C., 2003.

> Brilon, W.; Breler, A.: Traffic Flow on Freeway Upgrades. Preprint 04-2953, Annual Meeting Transportation Research Board, Washington, D.C.,

2004.

> Gomes, G.; May, A.; Horowitz, R.: A Microsimulation Model of a CongestedFreeway using VISSIM. Preprint, Annual Meeting Transportation Research

Board, Washington, D.C., 2004. www.ptvamerica.com/library

> Department of Transport: Highway Agency, Manual for Roads & Bridges,

Volume 12, London 1996www.official-documents.co.uk/document/deps/ha/dmrb/vol12/index.htm




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D2E Fe Calibration-SIMModels Ppt