Travel Demand Modeling - Michigan Demand Modeling Don Mayle Jennifer Osborne Karen Faussett Michigan Department of Transportation Statewide and Urban Travel Analysis Section ... Military

Travel Demand ModelingTravel Demand Modeling

Don Don MayleMayleJennifer OsborneJennifer OsborneKaren Karen FaussettFaussett

Michigan Department of TransportationMichigan Department of TransportationStatewide and Urban Travel Analysis SectionStatewide and Urban Travel Analysis Section

December 3, 2008December 3, 2008

Presentation GoalPresentation Goal

Improve the utilization of travel demand Improve the utilization of travel demand models for Project level analysismodels for Project level analysisDescribe how travel demand models work Describe how travel demand models work Interpreting model outputs Interpreting model outputs Different types of analysis available Different types of analysis available

Presentation OverviewPresentation Overview

BackgroundBackgroundWhy we make modelsWhy we make modelsPrimary usesPrimary uses

NetworksNetworksStructure Structure AttributionAttribution

Traffic Analysis ZonesTraffic Analysis ZonesStructure Structure DataData


Trip generationTrip generationNumber of person trips by Traffic Analysis Number of person trips by Traffic Analysis Zone (TAZ)Zone (TAZ)

Trip distributionTrip distributionTAZ to TAZ TAZ to TAZ

Mode SplitMode SplitConvert person trips to different modes of Convert person trips to different modes of traveltravel

AssignmentAssignmentAssign the route for the vehicle tripsAssign the route for the vehicle trips

Presentation OverviewPresentation OverviewCalibration and Validation Calibration and Validation

Standards for performanceStandards for performance

Different capabilities of different urban Different capabilities of different urban modelsmodels

All model utilize different techniques All model utilize different techniques depending on the model areadepending on the model area

Statewide model Statewide model General model assumptionsGeneral model assumptions

The basis for equations The basis for equations


Model applications Model applications Uses of the model Uses of the model

Discussion on using travel demand models Discussion on using travel demand models for project level analysisfor project level analysis

Information request processInformation request processLevels and types of analysis Levels and types of analysis Working together to enhance the final productWorking together to enhance the final product

Why Urban Models are Why Urban Models are DevelopedDeveloped

Metropolitan Planning Organizations (MPOs) are Metropolitan Planning Organizations (MPOs) are required to have an objective method to required to have an objective method to evaluate the federal aid road system as part of evaluate the federal aid road system as part of their Long Range Plan (LRP)their Long Range Plan (LRP)MDOT holds the models for Small MDOT holds the models for Small MPOsMPOs

50,000 50,000 –– 200,000200,000

Transportation Management Areas (Transportation Management Areas (TMAsTMAs) are ) are required to have a model and staff that are required to have a model and staff that are knowledgeable in modelingknowledgeable in modeling

Over 200,000Over 200,000

MPO Model BoundariesMPO Model Boundaries

Primary Uses of ModelPrimary Uses of Model

Forecasts Forecasts How changes in SocioHow changes in Socio--Economic data (SEEconomic data (SE--data) affect traffic flows data) affect traffic flows Predict future traffic congestionPredict future traffic congestionTest solutionsTest solutions

System wide analysis System wide analysis How changes in the network affect traffic How changes in the network affect traffic flowsflows

Primary Uses of ModelPrimary Uses of ModelDevelopment of Development of MPOsMPOs LRP Project list LRP Project list Test alternative methods for alleviating Test alternative methods for alleviating congestioncongestion

Not just widening roadsNot just widening roadsParallel corridorParallel corridorConnectivity improvements Connectivity improvements

Congestion management Congestion management Use a volume over capacity (V/C) ratio to Use a volume over capacity (V/C) ratio to identify deficiencies or congestionidentify deficiencies or congestionHierarchy of congestion Hierarchy of congestion

Air QualityAir Quality

Travel demand model outputs provide the Travel demand model outputs provide the inputs for air quality modelsinputs for air quality models

Vehicle Miles Traveled (VMT) Vehicle Miles Traveled (VMT) Vehicle Hours Traveled (VHT) Vehicle Hours Traveled (VHT) congested speedcongested speed

What is ModeledWhat is Modeled

Collectors and aboveCollectors and aboveAll capacity projects need to be in the LRP All capacity projects need to be in the LRP and the Transportation Improvement and the Transportation Improvement Program (TIP)Program (TIP)

LRP has at least a 20 year horizonLRP has at least a 20 year horizonTIP has a four year horizonTIP has a four year horizon

All future capacity projects identified in All future capacity projects identified in the LRP need to be modeled in forecaststhe LRP need to be modeled in forecasts

What is ModeledWhat is Modeled

A build network represents all of the A build network represents all of the capacity projects to be completed by the capacity projects to be completed by the year of the networkyear of the networkA noA no--build network represents the existing build network represents the existing road system road system A TIP or Existing plus Committed (E + C) A TIP or Existing plus Committed (E + C) network represents current conditions and network represents current conditions and the capacity projects in the TIPthe capacity projects in the TIP

Model UpdatesModel Updates

The model inputs are developed, reviewed The model inputs are developed, reviewed and approved by the MPO committee as and approved by the MPO committee as part of their LRP processpart of their LRP processUrban models are updated for each LRP Urban models are updated for each LRP

Air quality nonAir quality non--attainment or maintenance attainment or maintenance areas every 4 years areas every 4 years Air quality attainment areas every 5 years Air quality attainment areas every 5 years

Model UpdatesModel Updates

Updates can range from developing new Updates can range from developing new SESE--data to a complete rebuilddata to a complete rebuildInterim updatesInterim updatesTip amendments involving capacity Tip amendments involving capacity projects require new air quality conformity projects require new air quality conformity analysisanalysis

What is a Travel Demand ModelWhat is a Travel Demand Model

A travel demand model is a series of A travel demand model is a series of mathematical equations which are used to mathematical equations which are used to estimate traffic conditionsestimate traffic conditions

NetworksNetworks

Network StructureNetwork StructureBase Year Road NetworkBase Year Road Network

Michigan Geographic FrameworkMichigan Geographic FrameworkFederal Aid Roads (Collector and above)Federal Aid Roads (Collector and above)Add Local roads as neededAdd Local roads as needed

Framework “all roads” fileFramework “all roads” file

Framework with model networkFramework with model network

Network AttributesNetwork Attributes

Number of Thru LanesNumber of Thru LanesPosted SpeedPosted SpeedLane WidthLane WidthParking AllowedParking AllowedCenter Turn Lane PresentCenter Turn Lane PresentArea Type Area Type -- Urban, Rural, etc.Urban, Rural, etc.Percent Commercial TrafficPercent Commercial TrafficTraffic CountsTraffic Counts

Network AttributesNetwork Attributes

Purpose of AttributesPurpose of AttributesEstablish capacityEstablish capacityEstablish network speedEstablish network speedCreate turn prohibitions & penaltiesCreate turn prohibitions & penaltiesValidate with traffic countsValidate with traffic counts

CapacityCapacityMain uses:Main uses:

Equilibrium AssignmentEquilibrium AssignmentVolume to Capacity Ratio (VC Ratio)Volume to Capacity Ratio (VC Ratio)

Base Capacities are Level of Service (LOS) Base Capacities are Level of Service (LOS) D or E not Design CapacityD or E not Design Capacity

Daily CapacityDaily Capacity

CapacityCapacity

LookLook--up table up table Based on area typeBased on area typeNational Functional ClassificationNational Functional Classification

ModelsModelsGrand RapidsGrand RapidsSEMCOGSEMCOG

Capacity LookCapacity Look--up Tableup Table

7700770044Divided Divided ArterialArterial

CBDCBD

7500750022Divided Divided ArterialArterial

CBDCBD

187001870044FreewayFreewayResidentialResidential

179001790022FreewayFreewayCBDCBD

Capacity Per Capacity Per LaneLane

Number of Number of LanesLanes

Facility TypeFacility TypeArea TypeArea Type

CapacityCapacity

All other Models use:All other Models use:Capacity CalculatorCapacity Calculator

Developed by Lansing TMADeveloped by Lansing TMAUses 2000 and 1997 Highway Capacity Uses 2000 and 1997 Highway Capacity ManualManualUpdated in 2006 to 2000 HCMUpdated in 2006 to 2000 HCM

Some Model Capacities adjusted by Some Model Capacities adjusted by localslocals

CapacityCapacity

Attributes used in Calculating CapacityAttributes used in Calculating CapacityArea typeArea typeLink typeLink typeTraffic Operation CodeTraffic Operation CodeNumber of thru lanesNumber of thru lanesLane widthLane width-- Travel LaneTravel LaneOne or Two Way TrafficOne or Two Way TrafficPercentage CommercialPercentage CommercialTrunklineTrunklineParking AllowedParking Allowed

CapacityCapacity

Uses default green time based on Area Uses default green time based on Area Type and Facility TypeType and Facility Type

Adjustments to base capacity based on Adjustments to base capacity based on each attributeeach attribute

CapacityCapacity

102311001100110017050852510230.12Pulaski

67076080016001118255916710.12Chicago

63571980016001058252916350.12Chicago

62071980016001035051756210.12Dayton

65576080016001091654586550.12Dayton

67876080016001131656586790.12Dayton

102311001100110017050852510230.12Pulaski

67876080016001131656586790.12Dayton

66371980016001105055256630.12Dayton

65276080016001086654336520.12Dayton

102311001100110017050852510230.12Pulaski

Cap_4Cap_3Cap_2BASECAP24HrCap_2w24HrCap_1wCAPACITY_2006PK_HR_FNAME

SpeedSpeedUsed as a measure of time (how fast you Used as a measure of time (how fast you can travel)can travel)Important for Network PathsImportant for Network PathsReflects roadway conditions without the Reflects roadway conditions without the effect of congestioneffect of congestion

SpeedSpeed

Determining SpeedsDetermining SpeedsPosted speed limitPosted speed limit

Limit set by a jurisdictionLimit set by a jurisdiction

LookLook--up tablesup tablesBased on area type, facility type, number of lanes, Based on area type, facility type, number of lanes, posted speedposted speed

Speed Table (Holland)Speed Table (Holland)

202022202099993535223535191949.5349.534445456661.5961.594455555563.8563.8544555522505022454522757522707011

Model Model SpeedSpeed

Thru LanesThru LanesPosted Posted SpeedSpeed

Functional Functional ClassClass

Speed Table (Relative)Speed Table (Relative)

1 MPH added based on number of lanes, including center turn lane1 MPH added based on number of lanes, including center turn laneform default of 2.form default of 2.

42423535303025252020AllAll66CollColl--ectorector

494945453737303025253344Major Major ArtArt

535349494141343429292233Trunk Trunk lineline

656565656060555550501111FreeFree--wayway

RuralRuralFringeFringeSubSubUrbanUrbanCBDCBDRoadRoadLinkLinkFacilityFacility

Turning MovementsTurning Movements

No Intersection right and left turn lanesNo Intersection right and left turn lanesNo Traffic lightsNo Traffic lightsTurns ProhibitedTurns Prohibited

Added to rampsAdded to rampsIntersectionsIntersections

Turn Penalties (sometimes used)Turn Penalties (sometimes used)GlobalGlobalSpecificSpecific

Turning MovementsTurning Movements

Traffic Analysis Zones (TAZ)Traffic Analysis Zones (TAZ)

What Are Traffic Analysis Zones What Are Traffic Analysis Zones (TAZs)(TAZs)

Small geographic subdivisions of the study Small geographic subdivisions of the study areaareaBuilt from adjacent census blocks that Built from adjacent census blocks that have similar land use have similar land use

Allows the aggregation of census block data Allows the aggregation of census block data for households and populationfor households and population

Merged Census BlocksMerged Census Blocks

CentroidsCentroids

A point or node in the network A point or node in the network Corresponding to a TAZCorresponding to a TAZTrips loaded from Trips loaded from centroidscentroidsTrips travel from Trips travel from centroidscentroids to to centroidcentroidGenerally placed at center of TAZ activityGenerally placed at center of TAZ activity

Merged Census BlocksMerged Census Blocks

CentroidCentroid ConnectorsConnectors

Connectors represent the local roads not Connectors represent the local roads not in the network and all driveway cuts along in the network and all driveway cuts along a road segmenta road segment

Loading points Loading points Statewide model utilizes single point loadingStatewide model utilizes single point loading

Developing Developing TAZsTAZs

TAZsTAZs are developed before the are developed before the centroidcentroidconnectorsconnectors

designed so that the connectors can be designed so that the connectors can be properly createdproperly created

Building ConnectorsBuilding ConnectorsNo intersectionsNo intersectionsNo connections where physical barrierNo connections where physical barrierConnect where road isConnect where road is


Constrained by the networkConstrained by the networkThis facilitates the loading of trips to the This facilitates the loading of trips to the network network

Developing TAZsDeveloping TAZs

Constrained by natural featuresConstrained by natural featuresThis helps prevent impossible loadingsThis helps prevent impossible loadings


Constrained by political boundariesConstrained by political boundariesThis aids in developing the socioThis aids in developing the socio--economic economic data data TAZ data for a jurisdiction can be added up TAZ data for a jurisdiction can be added up and compared to control totals and compared to control totals

SocioSocio--Economic Data (SEEconomic Data (SE--Data)Data)Households and PopulationHouseholds and Population

Households and populationHouseholds and populationStart with census block dataStart with census block dataAdjust to base year Adjust to base year Forecast to future yearsForecast to future years

Demographics specialist Garth Demographics specialist Garth BanningaBanninga creates creates growth rates or control totals utilizing REMI, growth rates or control totals utilizing REMI, Woods and Poole and other sources that most Woods and Poole and other sources that most small small MPOsMPOs utilizeutilizeSpecific information on the area is requested from Specific information on the area is requested from local agencies and incorporated local agencies and incorporated

SocioSocio--Economic Data (SEEconomic Data (SE--Data)Data)Employment DataEmployment Data

Employment data usually comes from Employment data usually comes from ClaritasClaritas and MESA and MESA

The data is cleaned in house and then The data is cleaned in house and then reviewed by local road agencies and officialsreviewed by local road agencies and officials

It is in the form of a point fileIt is in the form of a point fileEach record is tagged with a TAZ numberEach record is tagged with a TAZ number

SocioSocio--Economic Data (SEEconomic Data (SE--Data)Data)Employment DataEmployment Data

The number of employees for each The number of employees for each business are aggregated by the type of business are aggregated by the type of employment (retail, nonemployment (retail, non--retail, service and retail, service and other) to TAZ totalsother) to TAZ totals

Average Autos AvailableAverage Autos Available

Start with Block Group dataStart with Block Group dataAverage number of autos available per Average number of autos available per household methodhousehold methodCategories autos methodCategories autos method

Number of 0, 1, 2, 3+ car householdsNumber of 0, 1, 2, 3+ car households

IncomeIncome

Start with census block dataStart with census block dataCan use average or categories Can use average or categories

TAZ Level SETAZ Level SE--DataData

Aggregated dataAggregated dataPopulationPopulationNumber of occupied householdsNumber of occupied householdsPersons per householdPersons per household

Average or categorized Average or categorized

Number of employees by business typeNumber of employees by business typeNumber of autos per householdNumber of autos per household

Average or categorizedAverage or categorized

Some models use household incomeSome models use household incomeAverage or categorizedAverage or categorized

SocioSocio--Economic Data (SEEconomic Data (SE--Data)Data)

The base and future years SEThe base and future years SE--Data is Data is reviewed and approved through the MPO reviewed and approved through the MPO committee structurecommittee structure

Trip GenerationTrip Generation

Trip GenerationTrip Generation

Estimation of person trips produced by or Estimation of person trips produced by or attracted to a TAZattracted to a TAZCalculated by Household & Employment Calculated by Household & Employment datadata

Data SourcesData Sources

National Cooperative Highway Research National Cooperative Highway Research Program (NCHRP)Program (NCHRP)

NCHRP 365 Report NCHRP 365 Report ––Travel Estimation Travel Estimation Techniques for Urban PlanningTechniques for Urban Planning

MI Travel CountsMI Travel CountsMichigan statewide household travel survey Michigan statewide household travel survey

2004/20052004/2005

PurposesPurposesHomeHome--Based & NonBased & Non--Home Based WorkHome Based WorkHomeHome--Based & NonBased & Non--Home Based OtherHome Based OtherHomeHome--Based School & NonBased School & Non--Home Based Home Based SchoolSchoolHomeHome--Based Shopping & NonBased Shopping & Non--Home Based Home Based ShoppingShoppingHomeHome--Based University & NonBased University & Non--Home Based Home Based UniversityUniversity

Trip Purpose Trip Purpose

Trip Production & Trip AttractionTrip Production & Trip Attraction

Trip production is where the trip is Trip production is where the trip is generatedgeneratedTrip attraction is where the trip is Trip attraction is where the trip is attractedattractedFor HomeFor Home--based trips the home end is based trips the home end is always the production endalways the production end

Trip PurposeTrip Purpose

HomeW ork

Home Based Work Home Based Other

Non-Home Based

Retail Mall

Cross Classification TableCross Classification TableBased on Autos and HH Size forBased on Autos and HH Size for

HomeHome--Based Other Daily Trip PurposeBased Other Daily Trip Purpose

9.216.613.610.67.63.7Avg

13.218.015.111.98.44.03+

10.616.713.310.68.14.026.313.711.59.26.74.01

3.911.29.27.44.82.60Autos Per

House hold

Avg5+4321

Persons Per Household

ProductionsProductionsNumber of HouseholdsNumber of Households

8533+

2812162821321

121290Autos Per

House hold

Total5+4321

Persons Per HouseholdTAZ 2156 HH

ProductionsProductionsHouseholds *Trip RateHouseholds *Trip Rate

Total Productions =

5*11.93*8.43+

12*13.3

16*8.12

2*13.71*11.53*6.72*4.01

1*7.42*4.89*2.60Autos Per

House hold

Total5+4321


ProductionsProductionsDaily HBO TripsDaily HBO Trips

Total Productions = 481.3

84.759.525.23+

289.2159.6129.62

6727.411.520.18.01

40.47.49.623.40Autos Per

House hold

Total5+4321


Trip ProductionTrip Production

Cross Classification MethodCross Classification MethodTotal Households Total Households Autos per household Autos per household Household size Household size Students per householdStudents per householdIncome ClassIncome Class

Trip AttractionTrip Attraction

Regression equationsRegression equationsTotal occupied householdsTotal occupied householdsTotal employmentTotal employmentRetail employmentRetail employmentService employmentService employmentOther (non retail or service) employmentOther (non retail or service) employmentArea typeArea type

Trip AttractionTrip AttractionExampleExample

HBO= (9.0*RE)+(1.7*SE)+(0.5*OE)+(0.9*HH)HBO= (9.0*RE)+(1.7*SE)+(0.5*OE)+(0.9*HH)HBO= (9.0*25)+(1.7*68)+(0.5*10)+(0.9*56) = HBO= (9.0*25)+(1.7*68)+(0.5*10)+(0.9*56) =

396 396 HomeHome--Based Other Person Trip AttractionsBased Other Person Trip Attractions

TAZ 12TAZ 12Households = 56Households = 56Retail Employment = 25Retail Employment = 25Service Employment = 68Service Employment = 68Other Employment = 10Other Employment = 10

Special GeneratorSpecial Generator

Special GeneratorsSpecial GeneratorsLand use with unusually high or low generation Land use with unusually high or low generation characteristicscharacteristics

AirportAirportUniversityUniversityMilitary baseMilitary baseHospitalsHospitals

Trip Generation HandbookTrip Generation HandbookMethods for IncludingMethods for Including

Add to TAZAdd to TAZReplace TAZ Productions & AttractionsReplace TAZ Productions & Attractions

Special GeneratorSpecial Generator

Models with Special GeneratorsModels with Special GeneratorsLansingLansingTriTri--City (BayCity (Bay--MidlandMidland--Saginaw)Saginaw)KalamazooKalamazooMuskegonMuskegonJacksonJacksonFlintFlintSEMCOGSEMCOGAnn ArborAnn Arbor


78078089089016381638201420141307130715921592TotalTotal

22227537535355351585158532532513671367205205

654654121278078015156986981111204204

88909011112162161515156156203203

969635353123121981982692695858202202

NHBANHBANHBPNHBPHBOAHBOAHBOPHBOPHBWAHBWAHBWPHBWPTAZTAZ

BalancingBalancing

Total Productions & Attractions need to be equalTotal Productions & Attractions need to be equalIf a trip is made to work, there needs to be a return If a trip is made to work, there needs to be a return trip.trip.

Balance by Productions for HomeBalance by Productions for Home--based Purposebased PurposeBalance by Attractions for NonBalance by Attractions for Non--Home PurposeHome Purpose


7807802014201415921592

7808901638201413071592Total

22753*% or Replace

535*%1585325*%1367205

65412*% or Replace

780 *%15698*%11204

890*% or Replace

11*%21615*%156203

9635*% or Replace

312*%198269*%58202

NHBANHBPHBOAHBOPHBWAHBWPTAZ


7807802014 (+376)

20141592 (+285)

1592Total

2222658 (+123)

1585396 (+71)

1367205

654654959 (+179)

15850 (+152)

11204

8814 (+3)21618 (+3)156203

9696383 (+71)

198 328 (+59)

58202

NHBANHBPHBOAHBOPHBWAHBWPTAZ

Trip DistributionTrip Distribution

Trip DistributionTrip DistributionTrip distribution joins the productions to Trip distribution joins the productions to the attractionsthe attractionsGravity model Gravity model

Interaction between two Interaction between two TAZsTAZsThe relative size of the TAZThe relative size of the TAZTravel time on the network and friction Travel time on the network and friction factors measure the distance between factors measure the distance between TAZsTAZs

Friction Factor CurveFriction Factor Curve

0

50000

100000

150000

200000

250000

1 3 5 7 9 11 13 15 17 19 21 23 25 27 29

Travel Time

Fric

tion

Fact

ors

HBWHBONHB

400 HBW P

350 HBW A

150 HBW A

100 HBW A

250 HBW

50 HBW

100 HBW

Distribution MatrixDistribution Matrix

Mode ChoiceMode Choice


What is Mode Choice?What is Mode Choice?Assigning Person Trips to mode of travelAssigning Person Trips to mode of travelWhat models have Mode Choice?What models have Mode Choice?

TMA ModelsTMA Models

LogitLogit ModelModel


Example Different Modes used:Example Different Modes used:Drive AloneDrive Alone2 Person shared ride2 Person shared ride3+ Person shared ride3+ Person shared rideTransitTransitNonNon--motorizedmotorized

Nested Nested LogitLogit

Person TripMode Choice

Auto Transit Non-motorized

SingleOccupancy Bus TrainCarpool

Auto OccupancyAuto OccupancyAuto Occupancy Auto Occupancy

Trip Distribution = Person TripsTrip Distribution = Person TripsAuto Occupancy factors are applied by trip Auto Occupancy factors are applied by trip purposepurpose

Different Rates for Different ModelsDifferent Rates for Different Models

Person Trips Person Trips →→ Vehicle Trips (HBW, HBO, NHB)Vehicle Trips (HBW, HBO, NHB)Source Data:Source Data:

NCHRP 365NCHRP 365MI Travel CountsMI Travel CountsArea Specific StudiesArea Specific Studies

Auto Occupancy RatesAuto Occupancy Rates

NCHRP 365NCHRP 365

1.661.66NHBNHB

1.671.67HBOHBO

1.111.11HBWHBW

Auto OccupancyAuto Occupancy

22.422.484.384.3444.5444.564.364.353.753.755

118.5118.519.819.814.614.6222.9222.933.933.944

156.8156.875.475.410.310.389.989.914.314.333

43.943.955.955.9864.5864.512.612.622.222.222

146.8146.812.512.589.489.453.953.921.221.211

5544332211TAZTAZHome-Based Other Person Trips


22.422.484.384.3444.5444.564.364.353.753.755

118.5118.519.819.814.614.6222.9222.933.933.944

156.8156.875.475.410.310.389.989.914.314.333

43.943.955.955.9864.5864.512.612.622.222.222

146.8146.812.512.589.489.453.9/1.6753.9/1.6721.2/1.6721.2/1.6711

5544332211TAZTAZHome-Based Other Person Trips to Vehicle Trips-1.67


P 22.4V 13.4

P 84.3V 50.5

P 444.5V 266.2

P 64.3V 38.5

P 53.7V 32.2

5

P 118.5V 71.0

P 19.8V 11.9

P 14.6V 8.7

P 222.9V 133.5

P 33.9V 76.5

4

P 156.8V 93.9

P 75.4V 45.2

P 10.3V 6.2

P 89.9V 53.8

P 14.3V 8.6

3

P 43.9V 26.3

P 55.9V 33.5

P 864.5V 517.7

P 12.6V 7.5

P 22.2V 13.3

2

P 146.8V 87.9

P 12.5V 7.5

P 89.4V 53.5

P 53.9V 32.3

P 21.2V 12.7

1

54321TAZHome-Based Other Person Trips to Vehicle Trips

PA to OD ConversionPA to OD Conversion

Trips are distributed as Productions and Trips are distributed as Productions and AttractionsAttractionsNeed to transpose to Origins & Need to transpose to Origins & DestinationsDestinations

HomeHome--Based TripsBased Trips

Home-Based Other Person Trips to Vehicle Trips

PA to OD ConversionPA to OD Conversion

Home

Work

Production

Attraction

Destination

Origin

AssignmentAssignment

Delay function Delay function -- BPR CurveBPR Curve

An equation that tells the model how to An equation that tells the model how to adjust the speed of a link depending on adjust the speed of a link depending on the V/C ratiothe V/C ratioC_timeC_time = F_time(1 + = F_time(1 + a(v/c)a(v/c)bb))Can be adjusted globally and/or on an Can be adjusted globally and/or on an individual link basis individual link basis

BPR curveBPR curve

Traffic AssignmentTraffic Assignment

Inputs: Inputs: Final Total O&D Matrix of Vehicle TripsFinal Total O&D Matrix of Vehicle Trips

Road Network Road Network Travel TimeTravel Time11--Way CapacityWay CapacityOptional specific Alpha and Beta valuesOptional specific Alpha and Beta valuesTurn prohibition/penalty file Turn prohibition/penalty file

MethodsMethodsAll or NothingAll or Nothing –– assigns all trips to shortest assigns all trips to shortest path (capacity is not a factor)path (capacity is not a factor)

Statewide Model uses All or NothingStatewide Model uses All or Nothing

User EquilibriumUser EquilibriumAssigns all trips to shortest path until traffic Assigns all trips to shortest path until traffic volumes become congested then assigns the volumes become congested then assigns the remainder to the new shortest pathremainder to the new shortest pathGoes through a series of iterations until it reaches Goes through a series of iterations until it reaches a level of convergencea level of convergence

Traffic AssignmentTraffic Assignment

Time of DayTime of Day


Assignment volumes available for 24Assignment volumes available for 24--hour hour daily time perioddaily time periodSome models have assignments by Peak Some models have assignments by Peak PeriodPeriod

Peak Period assignment volumes added to get Peak Period assignment volumes added to get 2424--hour dailyhour daily


Models with Peak Period assignmentModels with Peak Period assignmentHollandHollandLansingLansingSEMCOGSEMCOGFlint Flint Ann ArborAnn Arbor


Peak PeriodsPeak PeriodsAM Peak AM Peak -- 7am7am--9am, 6am9am, 6am--9am (Flint)9am (Flint)PM Peak PM Peak -- 3pm3pm--6pm6pmOff Peak Off Peak -- all other hours (Lansing, Holland)all other hours (Lansing, Holland)MidMid--Day Day –– 9am9am--3pm (SEMCOG, AA, Flint)3pm (SEMCOG, AA, Flint)EveningEvening--7pm7pm--6am (SEMCOG, AA)6am (SEMCOG, AA)EveningEvening--6pm6pm--6am (Flint)6am (Flint)

Calibration & ValidationCalibration & Validation

CalibrationCalibration

CalibrationCalibrationAdjustments made to achieve desired resultsAdjustments made to achieve desired results

ValidationValidationHow well the results match the criteria at How well the results match the criteria at each stepeach step

Calibration Flow ChartCalibration Flow ChartModel Inputs

Validation

Trip Generation

Validation

Trip Distribution

Validation

Mode Choice

Validation

Trip Assignment

Validation


Adjustments at each stepAdjustments at each stepTrip GenerationTrip Generation

Adjust Trip rate tablesAdjust Trip rate tablesUse Area TypesUse Area TypesUse different variablesUse different variables

WorkersWorkersAverages or CategoriesAverages or Categories

Adjust Attraction EquationsAdjust Attraction Equations


Adjustments at each stepAdjustments at each stepTrip DistributionTrip Distribution

Adjust Friction FactorsAdjust Friction FactorsAdjust method of applying friction factorsAdjust method of applying friction factors

AssignmentAssignmentAdjust the BPR CurveAdjust the BPR Curve


Adjustments at each stepAdjustments at each stepVehicle TripsVehicle Trips

Auto Occupancy ratesAuto Occupancy rates

Network pathsNetwork pathsTurn penaltiesTurn penaltiesSpeedsSpeeds

Network PathsNetwork PathsReasonable PathsReasonable Paths

Use Shortest Path toolsUse Shortest Path toolsShortest PathShortest PathK Shortest PathK Shortest Path

WhyWhyConnectivityConnectivityTravel TimesTravel TimesIllogical travel patternsIllogical travel patterns

Network PathsNetwork Paths

Traffic CountsTraffic Counts

Traffic counts for base yearTraffic counts for base yearModified raw countsModified raw counts

Seasonal VariationSeasonal Variation

Average annual daily traffic (AADT)Average annual daily traffic (AADT)TrunklineTrunkline & local roads& local roads

CountsCounts+/+/-- 2 years from Base Year.2 years from Base Year.

Traffic CountsTraffic Counts

Where counts come fromWhere counts come fromMDOTMDOTLocal Road CommissionsLocal Road CommissionsPlanning AgenciesPlanning Agencies

MDOT Assignment Validation MDOT Assignment Validation StandardsStandards

Area wide VMT: +/Area wide VMT: +/-- 5% 5% (Assignment/count)(Assignment/count)Area Type +/Area Type +/--10%10%

CBD, Urban, Suburban, Fringe, RuralCBD, Urban, Suburban, Fringe, RuralScreenline: +/Screenline: +/-- 5% 5% Cutline: +/Cutline: +/-- 10% 10%

LINK TYPE LINK TYPE Validation StandardsValidation Standards

+/+/-- 25%25%+/+/-- 20%20%CollectorCollector

+/+/-- 20%20%+/+/-- 10%10%Minor Arterial Minor Arterial

+/+/-- 10%10%+/+/-- 7%7%Major Arterial Major Arterial

NO STANDARDNO STANDARD+/+/-- 6%6%TrunklineTrunkline

NO STANDARDNO STANDARDNO STANDARDNO STANDARDRampsRamps

+/+/-- 7%7%+/+/-- 6%6%FreewayFreeway

FHWA FHWA StandardsStandards

MDOT MDOT Standards Standards

LINK TYPELINK TYPE

VOLUME GROUP VOLUME GROUP Validation StandardsValidation Standards

Individual link targets (percent deviation of Individual link targets (percent deviation of assignment/count volumes on a linkassignment/count volumes on a link--byby--link basis) link basis)

+/+/-- 47%47%+/+/-- 100%100%1,000 1,000 –– 2,5002,500

+/+/-- 60%60%+/+/-- 200%200%< 1,000 < 1,000

+/+/-- 36%36%+/+/-- 50%50%2,500 2,500 –– 5,0005,000

+/+/-- 29%29%+/+/-- 25%25%5,000 to 10,0005,000 to 10,000

+/+/-- 25%25%+/+/-- 20%20%10,000 to 25,00010,000 to 25,000

+/+/-- 22%22%+/+/-- 15%15%25,000 25,000 –– 50,00050,000

+/+/-- 21%21%+/+/-- 10%10%> 50,000> 50,000

FHWA StandardsFHWA StandardsMDOT StandardsMDOT StandardsVolume GroupVolume Group

ValidationValidation

Only calculate validation criteria using Only calculate validation criteria using links with countslinks with countsPercent of links validated to volume group Percent of links validated to volume group

Should be above 80%Should be above 80%

Model DifferencesModel Differences


Years AvailableYears AvailableDifferent Base YearsDifferent Base YearsDifferent Horizon YearsDifferent Horizon YearsDifferent Air Quality Years Different Air Quality Years

Projects are group by these yearsProjects are group by these years

Model YearsModel Years

1998 Base Year1998 Base YearKalamazoo (updating to 2008)Kalamazoo (updating to 2008)

2000 Base Year2000 Base YearHolland (updating to 2009)Holland (updating to 2009)GVMC (updating to 2009)GVMC (updating to 2009)Traverse CityTraverse City

2002 Base Year2002 Base YearMuskegon (updating to 2009)Muskegon (updating to 2009)Battle Creek Battle Creek

2004 Base Year2004 Base YearJacksonJackson


2005 Base Year2005 Base YearStatewideStatewideLansing Lansing TriTri--City Regional ModelCity Regional ModelFlintFlintAnn ArborAnn ArborSEMCOGSEMCOG

2006 Base Year2006 Base YearBenton Harbor/St. JosephBenton Harbor/St. JosephNilesNiles


2030 Horizon Year2030 Horizon YearAnn ArborAnn ArborSEMCOGSEMCOGKalamazooKalamazooBattle CreekBattle Creek

2035 Horizon Year2035 Horizon YearAll other modelsAll other models


Update CyclesUpdate CyclesLRP Cycle LRP Cycle -- 4 or 5 year cycle4 or 5 year cycle

Jackson & TriJackson & Tri--city on 5 Yearcity on 5 Year

Interim UpdatesInterim UpdatesProject plan updatesProject plan updates

Project plan updatesProject plan updatesAny year that is not the base yearAny year that is not the base yearWhenever there is a capacity project Whenever there is a capacity project amendment to the TIP or LRPamendment to the TIP or LRP

Model DifferencesModel DifferencesWho builds and holds modelWho builds and holds model

MDOTMDOT

TMAsTMAs have their own models, MDOT holds copyhave their own models, MDOT holds copy

SEMCOGSEMCOGFlintFlintAnn ArborAnn ArborLansingLansingGrand RapidsGrand Rapids

StatewideStatewideNilesNiles

KalamazooKalamazoo

Traverse CityTraverse CityMuskegonMuskegonBattle CreekBattle CreekBenton Harbor/St. JosephBenton Harbor/St. JosephHollandHolland

JacksonJacksonTriTri--City ModelCity Model


Peak Period CapabilitiesPeak Period CapabilitiesTransit ModelsTransit Models

Lansing Lansing -- integratedintegratedFlint Flint -- integratedintegratedSEMCOG SEMCOG -- integrated integrated Grand Rapids Grand Rapids –– stand alonestand alone

Capacity DifferencesCapacity Differences


Model DesignModel DesignData SourcesData SourcesChanges made during CalibrationChanges made during Calibration

Statewide ModelStatewide Model

Statewide Model NetworkStatewide Model Network

Network ComparisonNetwork ComparisonStatewide Model TriStatewide Model Tri--County ModelCounty Model

Zones and Loadings ComparisonZones and Loadings ComparisonStatewide Model TriStatewide Model Tri--County ModelCounty Model

Urban Models:Urban Models: Statewide Model:Statewide Model:

Home Based WorkHome Based Work Home Based Work/BusinessHome Based Work/BusinessHome Based OtherHome Based Other Home Based Social RecreationHome Based Social Recreation

Home Based OtherHome Based Other

NonNon--Home BasedHome Based NonNon--Home Based Work/BusinessHome Based Work/BusinessNonNon--Home Based OtherHome Based Other

Trip PurposesTrip Purposes

Urban Models:Urban Models: Statewide Model:Statewide Model:

Households (Households (avgavg or by cat)or by cat) Households by Size (1Households by Size (1--5+ persons)5+ persons)Autos per Household Autos per Household Households by IncomeHouseholds by IncomeIncomeIncome per Household per Household (low, medium, high)(low, medium, high)

Total EmploymentTotal Employment Manufacturing EmploymentManufacturing EmploymentRetail EmploymentRetail Employment Other Basic (farming, fishing, mining) Other Basic (farming, fishing, mining) Service Employment RetailService Employment RetailOther Employment WholesaleOther Employment Wholesale

ServiceServiceOther (insurance, real estate, finance)Other (insurance, real estate, finance)

Data RequirementsData Requirements

Statewide Model:Statewide Model:AllAll--OrOr--Nothing Traffic AssignmentNothing Traffic Assignment

All the traffic traveling between two zonesAll the traffic traveling between two zonesuses the shortest path between the zones.uses the shortest path between the zones.

Traffic traveling between two zones uses the shortest path untilTraffic traveling between two zones uses the shortest path until congestion congestion causes the speed to drop, at which time it diverts to another facauses the speed to drop, at which time it diverts to another faster path.ster path.

Urban Models:Urban Models:Equilibrium Traffic AssignmentEquilibrium Traffic Assignment

Why not use an Equilibrium Assignment Why not use an Equilibrium Assignment with the Statewide Model?with the Statewide Model?

The Statewide Model is mainly concerned The Statewide Model is mainly concerned with rural areas and freeway corridors in with rural areas and freeway corridors in which congestion is not as much of a which congestion is not as much of a problem as in urban areasproblem as in urban areas

The Statewide Model network is sparse The Statewide Model network is sparse and does not offer many opportunities for and does not offer many opportunities for traffic to divert in the event of congestion traffic to divert in the event of congestion

When should theWhen should theStatewide Model be used?Statewide Model be used?

When the analysis area is outside the urban When the analysis area is outside the urban model areasmodel areas

When a project may have significant impacts When a project may have significant impacts beyond the boundaries of an urban modelbeyond the boundaries of an urban model

When comparing two or more areas that would When comparing two or more areas that would fall in different urban modelsfall in different urban models

SUTA staff can recommend which model should SUTA staff can recommend which model should be used for a given analysisbe used for a given analysis

What are we doing toWhat are we doing toimprove the models?improve the models?

Models are currently being developedModels are currently being developedfrom the MI Travel Counts survey datafrom the MI Travel Counts survey data

Socioeconomic data has recently been Socioeconomic data has recently been updated with the latest REMI forecastsupdated with the latest REMI forecasts

A statewide truck model for commercial A statewide truck model for commercial traffic is under developmenttraffic is under development

AssumptionsAssumptions


Everyone has perfect knowledge of Everyone has perfect knowledge of networknetworkEveryone wants to minimize travel timeEveryone wants to minimize travel timeEveryone wants to go to closest Everyone wants to go to closest destinationdestination


Not ConsideredNot ConsideredTraffic SignalsTraffic SignalsAccess ManagementAccess ManagementGeometricsGeometricsHuman Behavior/PreferencesHuman Behavior/Preferences

Model Outputs & ApplicationsModel Outputs & Applications

Model OutputsModel Outputs

Travel demand models were designed for Travel demand models were designed for system wide analysissystem wide analysisPatterns and Changes not necessarily Patterns and Changes not necessarily specific numbersspecific numbers


VolumesVolumesTotal VolumesTotal VolumesVolume ChangesVolume ChangesGrowth FactorsGrowth Factors

Congested SpeedsCongested SpeedsUrban only Urban only

Vehicle Miles TraveledVehicle Miles TraveledVehicle Hours TraveledVehicle Hours Traveled


Volume to Capacity RatiosVolume to Capacity RatiosPost processing for StatewidePost processing for Statewide

Statewide model can post process for Statewide model can post process for commercial traffic utilizing the percent commercial traffic utilizing the percent commercial from Sufficiency commercial from Sufficiency

Types of AnalysisTypes of Analysis

Alternative TestingAlternative TestingProject SelectionProject Selection

Detour AnalysisDetour AnalysisAssignment differences based on temporary change Assignment differences based on temporary change in networkin networkDistribution remains the sameDistribution remains the same

Permanent Network ChangePermanent Network ChangeAssignment differences based on permanent change Assignment differences based on permanent change in networkin networkDistribution ChangesDistribution Changes


Project AnalysisProject AnalysisExpand/Decrease CapacityExpand/Decrease CapacityNew RoadsNew RoadsOneOne--Way ChangesWay ChangesSpeed ChangesSpeed ChangesChanges in ConnectivityChanges in Connectivity

Select Link AnalysisSelect Link AnalysisAll the trips that pass thru that link All the trips that pass thru that link Flows to and from a specific linkFlows to and from a specific link


Major Land Use ChangesMajor Land Use ChangesNew MallNew MallMajor Housing DevelopmentMajor Housing Development

SubSub--Area AnalysisArea AnalysisCorridorsCorridorsSmall Communities/AreasSmall Communities/Areas

Questions about Questions about Travel Demand Travel Demand

Models?Models?

Discussion Discussion Where do we go from here Where do we go from here

Presentation from Project Planning Presentation from Project Planning Cross divisional team Cross divisional team

Review of NCHRP Report 255Review of NCHRP Report 255Highway Traffic Data for Urbanized Area Project Highway Traffic Data for Urbanized Area Project Planning and DesignPlanning and Design

Review methods of other DOTSReview methods of other DOTSSet standards for requests and levels of Set standards for requests and levels of analysisanalysis

Thank you for participating! Thank you for participating!

Documents

Travel Demand Modeling - Michigan Demand Modeling Don Mayle Jennifer Osborne Karen Faussett Michigan Department of Transportation Statewide and Urban Travel Analysis Section ... Military