Tips, Trips, and Traps of TransCAD ModelingLSA Associates, Inc.September 2001North Carolina MPO Conference

AgendaWhy Model?Why Jurisdictions Convert to TransCAD?The Transportation ModelGIS Developers KitApplications

Why Model?Why do we model the transportation network?

Why Model?To consider the effects of land use, transportation, and air quality To determine infrastructure needs, costs, and timing as growth occursTo analyze land use and transportation alternativesTo provide a consistent platform for travel forecastingRequired by the federal government for metropolitan areas

The History of Travel ForecastingAggregate ModelsFew zonesMajor highway planning onlyComputers available to large agencies50s80s and 90s00s60s and 70sShift to microcomputersMore zonesDetailed transit and HOV modelsComputer chip technology advancesFederal government sponsorshipTravel behavior surveys widespreadBasic transit capabilityWindows-basedMore disaggregation and detailGIS-based modelsMicrosimulation

Why Jurisdictions Convert to TransCAD?Why are agencies converting their travel models to TransCAD?

Why Convert?Some widely-used older modeling software are no longer being supported a new modeling platform is requiredLimited capabilities inGraphicsMemoryGISNetwork sizeNumber of TAZs

TransCAD UsersThere are many states in America that currently use TransCAD

Geographic Information SystemsA GIS-based transportation modelCompatible with other GIS toolsSpatial AnalysisArcView Shape FilesTransCAD *.dbd Files

Why TransCAD?A powerful modeling software that can enhance the modeling process Windows-based menus that are intuitive to manipulateA GIS software with transportation modeling capabilitiesNo internal size limitationsScenario manager for easy file managementAbility to easily analyze intermediate resultsMapping and visualization tools designed for GIS and transportation applicationsTIP: Choose a powerful computer!

The Transportation ModelWhat is involved with a travel demand model?

Modeling Process

TransCAD InputsEasy to understand file structureNo restrictions on file names, locations, etc.File names are easy to change in the model structure with the scenario manager, created in GISDK

TransCAD OutputsChecking intermediate modeling results is easy in TransCADIdentifying results from an individual project area allows detailed study of the projectPerformance module allows consistent reporting of results

Data and DatabasesGeographic dataNetwork dataAttribute dataTransCAD model dataSocioeconomic dataUS Census dataJurisdictional boundariesZip codesRailroadsWater FeaturesTiger Streets Files

NetworksNetworks are GIS databasesConflation to GIS distances and shapesFoundation for traffic counts, performance, transit, and any other dataMulti-year network capabilityTIP: Keep raw count data and adjustments in traffic count database

Networks

Traffic Analysis Zone DataZonal areas used in modeling tripsAbility to incorporate census dataUsed for summaries and reportsUsed for visually verifying data

Socioeconomic DataInterface with popular GIS platformsLand use to socioeconomic conversion using TransCADs GIS toolsVisual representation of land use and socioeconomic dataTAZ coverage provides foundation for area-based data and is easily modifiedTIP: Socioeconomic sub-model can use a Fratar process coded in GISDK

Socioeconomic Data and TAZ Structure

Trip GenerationRobust cross classification production modelUnlimited trip purposes Production allocation and attraction allocation modelsTIP: Include all modeling steps in TransCAD using GISDK, without compromising model structure. This ensures a full running model from start to finish.

Trip GenerationIncorporate land use dataDetailed trip purposesDistance-based allocation modelsSpecial generatorsUniversitiesHospitalsAmusement parksEvent centersMallsGovernment installations

Trip DistributionTIP: Geocode survey data in house to determine trip lengthsDesire lines between TAZs and districtsTRIP: GISDK standard gravity evaluation procedure does not correctly apply K factors in version 3.6Friction factors calibrated curves versus lookup table

Mode AnalysisCustomized nested logit and multinomial logit modelsTIP: Dont be limited to standard TransCAD procedures, create exactly what you want with GISDKDistance-based bike and pedestrian equations

Nested Logit StructurePerson TripsMotorizedNon-MotorizedDrive AloneShared RideAuto PassengerTransitDA Non TollDA TollSR2 Non HOVSR2 HOVSR3 Non HOVSR3 HOVAuto ExpressAuto LocalWalk ExpressWalk LocalNon HOV Non TollHOV Non TollNon HOV TollHOV TollNon HOV Non TollNon HOV TollHOV Non TollHOV TollExpressUrban RailCommuter RailExpressUrban RailCommuter Rail

Traffic AssignmentTime of dayUser defined volume-delay equationsSpeed post-processingSpeed feedbackAM peak congested speedsOff peak freeflow speedsAll or nothing, capacity constrained assignments with comparison

TransCAD Transit CapabilitiesWalk access vs drive accessUnlimited number of modesUnlimited number of variablesStops dependent upon individual routes

Transit AssignmentTransit boardings by stop, by route, or by modeDrive or walk access assignmentTransit flows by linkTransit line volumes

ValidationScreenlines GIS line layer created quicklyTRIP: One way links confuse the built-in screenline analysis functions

Model Conversion ProcessTRIP: The base converted model is not ready to go!TIP: Develop performance reporting capabilities early.TRIP: TransCAD uses different distances this may affect model results.TRIP: Need to adjust for software differences.Existing ModelInitial Model Conversion(Caliper or LSA)Network Conflation and Model ReplicationModel EnhancementsCalibration / ValidationPerformance Reporting

GIS Developers KitThe endless possibilities with the TransCAD programming language

TransCAD Scripting CapabilityGISDK is the TransCAD programming languageAllows for complete automation of the modeling process unique to each modelEliminates user error by programming all steps and variables in a model runSimilar to programming in C++ (with different syntax and commands)Use the programming editor of your choice to create and edit the GISDK scriptTIP: Boxer Software is a good (and inexpensive) programming editor

Model User InterfaceThe dialog boxes that run the whole modelReduce errors by eliminating point/click/type commandsGISDK is the key to programming the model

TransCAD Dialog BoxesCustom user interfaces created using GISDKFully automates the model procedures including file names, variables, and summary reportsTIP: These really help the consistency and accuracy of the model!

Scenario ManagerCreated using GISDKManages all files related to each alternative

GIS Developers Kit (GISDK)Program exactly what we want TransCAD to doAllows for any mathematically sound method or procedureNot confined to standard TransCAD proceduresFull dialog box customization

Performance ReportingThe possibilities available for performance reporting

Performance ModuleProvides consistent and convenient summary reportsCreated with GISDKCustomized to the clients needs

Analysis tool for troubleshooting model runsFacilitates calibration and validationTIP: Create EARLY in modeling process!

Summary ReportsThe summaries are customized using GISDK and summarize the model data in many ways, includingFacility Type and Area TypeCapacity AnalysisCongestion DelayAir Quality Emissions Results

ApplicationsTransCAD applications for the transportation planning and analysis process

Land Use and TAZ OverlayLand Use MapTAZ MapLand Use and TAZ Overlay

I-25 Socioeconomic Data Analysis1998 Data2020 DataLand Use Data

I-25 Corridor Analysis1998 Data2020 DataLand Use Data

Supply and Demand AnalysisDemandSupplyDifference

Colorado Springs Alternatives Analysis

Buffer AnalysisMile BufferTravel Time Buffers

Traffic Impact AnalysisTrip Distribution for a proposed development

Traffic Impact Analysis

Site Selection / GeocodingFire stationsSchool sitesPark locations

Site Selection / Geocoding

Travel Sheds / Critical Link AnalysisIdentify users of a specific facilityAnalysis for Adequate Community Facilities Ordinances and road fee programs

GIS-Based Transportation Improvement Programs

AgencyProjectFunding AmountAnaheimLincoln Avenue Signal Coordination$52,910AnaheimState College Blvd @ SR-91$150,000Buena ParkArtesia Blvd @ 1-5 Interchange$132,795Costa MesaFairview Road$29,846IrvineBicycle Program$67,200

Transit Planning and OperationsStrategic transit planningUniversity transportation planningCorridor planningMarket identification and productivityManagement and placement of capital assets

Land Use / Transportation / Air QualityConceptual level analysis of LUTRAQ relationshipComprehensive plan updatesTriggers population vs. VMT growthAir quality and emissions inventoryStationary and mobile sourcesOn-road mobile emissions estimationMobile5Nonattainment areaEnergy and fuel consumption

Air Quality AnalysisLink-based emissionsZone-based emissions (i.e. cold starts, evaporate VOCs, etc.)Air quality conformity determinationsRedesignation and classification issuesIntegration with gridded urban airshed modelingIntegration with Mobile5

Land Use / Transportation / Air QualityAvailable from the performance summary report for the Fort Collins Nonattainment area

Integrated Air Quality ModelingTransCAD Travel Demand Model(speeds, vehicle miles of travel, time of day, )EPA Mobile/Part Emissions Models(temperatures, fuel characteristics, emission factors, )Emissions from On-Road Vehicles

GIS-Based Emissions Inventories

Intersection AnalysisSynchro Intersection AnalysisIntersection Flow Diagram Volumes from TransCADTraffic CountsNCHRP 255 ProcessVISSIM 3D AnimationSimTraffic 2D Animation

TransCAD Turn Movement Forecasts

SimTraffic Micro-Simulation

VISSIM Micro-Simulation

VISSIM Micro-Simulation

VISSIM Micro-Simulation

VISSIM Micro-Simulation

VISSIM Micro-Simulation

VISSIM Micro-Simulation

VISSIM Micro-Simulation

VISSIM Micro-Simulation

Construction ManagementModify signal timing in response to construction closures

Future TransCAD ApplicationsInteractive MPO Project Prioritization and Funding AllocationsTraffic Impact Studies: Cumulative improvements and impacts, time of day project distributionsFHWA TDM ModelMixed Use Activity Center Trip Generation & DistributionBicycle AssignmentsTransportation CorridorsPavement Management

LSA Associates, Inc.132 West Mountain AvenueFort Collins, CO 80524970.494.1568lsa.ftcollins@lsa-assoc.com

Tips, Trips, and Traps of TransCAD ModelingPresented by LSA Associates, Inc.September 2001North Carolina MPO ConferenceFayetteville, NC

Many states in America are using TransCAD. Some are just beginning, some have full running models. This map is not an exhaustive list.Ask the questionsWorking with TransCAD is very flexible and easy to understand. The scenario manager is a key.AVI Opens up the Lake Elsinore model dialog box. This dialog box runs the entire model from start to finish with one click of the button.AVI An example of a scenario manager. This is used to manage all model alternatives with the file names and a few parameters.AVI There is a LOT of information stored within the network. This avi shows the info tool and how the user can add data, change data, etc. The network includes a place for Accidents, Bicycle Information, etc.AVI This movie shows two conflation examples as well as a copy/paste example. The thin yellow lines are the city centerline streets, the thick lines are the model roadway network, color coded by facility type (the dotted green lines are centroid connectors). Most jurisdictions have current centerline files, and if not, TIGER files are available for the entire United States.AVI This shows a color map of household density. This is useful in verifying and correcting input data.AVI this shows a dot-density of different land use acreages in Lake Elsinore.AVI This shows a map with volume bandwidth. The movie displays the screenlines.GISDK is a very important tool when using TransCAD for running models. With GISDK, everything is programmed to do the exact same thing with the same variables each time it is run. File names can change easily within a scenario manager to create a new model run. One option to run the model is to go through the menus and use standard TransCAD procedures manually. This can produce many errors and can easily have consistency errors. The best option is to run the model through a dialog box such as this one. Every model run will perform the exact same procedures in the same order with the same parameters! These provide consistency between model users, so more than one person/department can correctly run models.Dialog boxes created with GISDK allow a user friendly environment to run the models.An example of the Mason Street model scenario manager. All input and output files are chosen with this dialog box. It uses typical Windows file open and file save as dialog boxes to find the correct files. Since file names can be named in a logical manner, it is easy to find the correct files.Scripting allows for full customization.A VERY important step!Summary reports allow the data to be summarized in the same way for each model run. This gives a great comparison tool between several model runs. You can be assured that the reports are summarizing the data in the exact same way no place for user error.AVI This is a geocoding example from Poudre High School. There were no zip codes available in the data, but we can just use the city to locate the addresses. TransCAD is very flexible in the way it geocodes.There has always been a concern about getting future intersection levels of service from a link based travel demand forecasting model. We have created an add-in for TransCAD which expedites getting the intersection levels of service into 3d animation.AVI a short video with the Turn movements programThe ending slide