Presentation on theme: "Agenda Why Model? Why Jurisdictions Convert to TransCAD?"— Presentation transcript:
0 Tips, Trips, and Traps of TransCAD Modeling LSA Associates, Inc.September 2001North Carolina MPO Conference
1 Agenda Why Model? Why Jurisdictions Convert to TransCAD? The Transportation ModelGIS Developer’s KitApplications
2 Why do we model the transportation network? Why Model?Why do we model the transportation network?
3 Why Model?To consider the effects of land use, transportation, and air qualityTo 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
4 The History of Travel Forecasting Aggregate ModelsFew zonesMajor highway planning onlyComputers available to large agencies50’sComputer chip technology advancesFederal government sponsorshipTravel behavior surveys widespreadBasic transit capability60’s and 70’s80’s and 90’sShift to microcomputersMore zonesDetailed transit and HOV modelsWindows-basedMore disaggregation and detailGIS-based modelsMicrosimulation00’s
5 Why Jurisdictions Convert to TransCAD? Why are agencies converting their travel models to TransCAD?
6 Why Convert?Some widely-used older modeling software are no longer being supported – a new modeling platform is requiredLimited capabilities inGraphicsMemoryGISNetwork sizeNumber of TAZs
7 There are many states in America that currently use TransCAD TransCAD UsersThere are many states in America that currently use TransCADMany states in America are using TransCAD. Some are just beginning, some have full running models. This map is not an exhaustive list.
8 Geographic Information Systems A GIS-based transportation modelCompatible with other GIS toolsSpatial AnalysisArcViewShape FilesTransCAD*.dbd Files
9 Why TransCAD?A powerful modeling software that can enhance the modeling processWindows-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!
10 The Transportation Model What is involved with a travel demand model?
11 Modeling Process Trip Generation Trip Distribution Mode Analysis Traffic AssignmentSocioeconomic DataRoadway NetworkTransit NetworkTransit RidershipTransit AssignmentRoadway VolumesPerformance ReportHow many trips?Where will they go?What mode?What route?Identify needsAlternatives analysisAsk the questions…
12 TransCAD Inputs Easy to understand file structure No restrictions on file names, locations, etc.File names are easy to change in the model structure with the scenario manager, created in GISDKWorking with TransCAD is very flexible and easy to understand. The scenario manager is a key.
13 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
14 Data and Databases Geographic data Network data Attribute data TransCAD model dataSocioeconomic dataUS Census dataJurisdictional boundariesZip codesRailroadsWater FeaturesTiger Streets Files
15 AVI – Opens up the Lake Elsinore model dialog box 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.
16 AVI – An example of a scenario manager AVI – An example of a scenario manager. This is used to manage all model alternatives with the file names and a few parameters.
17 Networks Networks are GIS databases Conflation 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
18 Project Selection (TIP/RTP) NetworksGIS NetworksRoadway SystemTransit RoutesAir QualityPerformanceTime of Day VolumesProject Selection (TIP/RTP)Traffic Counts
19 AVI – There is a LOT of information stored within the network 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.
20 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.
21 Traffic Analysis Zone Data Zonal areas used in modeling tripsAbility to incorporate census dataUsed for summaries and reportsUsed for visually verifying data
22 Socioeconomic Data Interface with popular GIS platforms Land use to socioeconomic conversion using TransCAD’s 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
23 Socioeconomic Data and TAZ Structure GIS TAZ StructureArea Type2020 Socioeconomic DataPerformance and Air QualityArea based IndexesK FactorsTerminal Penalties1998 Socioeconomic Data
24 AVI – This shows a color map of household density AVI – This shows a color map of household density. This is useful in verifying and correcting input data.
25 Trip Generation Robust cross classification production model Unlimited trip purposesProduction 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.
26 Trip Generation Incorporate land use data Detailed trip purposes Distance-based allocation modelsSpecial generatorsUniversitiesHospitalsAmusement parksEvent centersMallsGovernment installations
27 AVI – this shows a dot-density of different land use acreages in Lake Elsinore.
28 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
29 Mode Analysis Customized nested logit and multinomial logit models TIP: Don’t be limited to standard TransCAD procedures, create exactly what you want with GISDKDistance-based bike and pedestrian equations
30 Nested Logit Structure Person TripsMotorizedNon-MotorizedDrive AloneShared RideAuto PassengerTransitDA Non TollDA TollSR2 Non HOVSR2 HOVSR3 Non HOVSR3 HOVAuto ExpressAuto LocalWalk ExpressWalk LocalNon HOV Non TollNon HOV TollExpressUrban RailCommuter RailNon HOV Non TollNon HOV TollHOV Non TollHOV TollExpressUrban RailCommuter RailHOV Non TollHOV Toll
31 Traffic Assignment Time of day User defined volume-delay equations Speed post-processingSpeed feedbackAM peak – congested speedsOff peak – freeflow speedsAll or nothing, capacity constrained assignments with comparison
32 TransCAD Transit Capabilities Walk access vs drive accessUnlimited number of modesUnlimited number of variablesStops dependent upon individual routes
33 Transit Assignment Transit boardings by stop, by route, or by mode Drive or walk access assignmentTransit flows by linkTransit line volumes
34 Validation Screenlines – GIS line layer created quickly TRIP: One way links confuse the built-in screenline analysis functions
35 AVI – This shows a map with volume bandwidth AVI – This shows a map with volume bandwidth. The movie displays the screenlines.
36 Model Conversion Process Existing ModelTRIP: 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.Initial Model Conversion(Caliper or LSA)Network Conflation and Model ReplicationPerformance ReportingModel EnhancementsCalibration / Validation
37 The endless possibilities with the TransCAD programming language GIS Developer’s KitThe endless possibilities with the TransCAD programming language
38 TransCAD Scripting Capability GISDK 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 editorGISDK 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.
39 Model User Interface The dialog boxes that run the whole model Reduce errors by eliminating point/click/type commandsGISDK is the key to programming the modelOne 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.
40 TransCAD Dialog Boxes Custom user interfaces created using GISDK Fully automates the model procedures – including file names, variables, and summary reportsTIP: These really help the consistency and accuracy of the model!Dialog boxes created with GISDK allow a user friendly environment to run the models.
41 Scenario Manager Created using GISDK Manages all files related to each alternativeAn 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.
42 GIS Developer’s Kit (GISDK) Program exactly what we want TransCAD to doAllows for any mathematically sound method or procedureNot confined to standard TransCAD proceduresFull dialog box customizationScripting allows for full customization.
43 Performance Reporting The possibilities available for performance reporting
44 Performance Module Provides consistent and convenient summary reports Created with GISDKCustomized to the client’s needsAnalysis tool for troubleshooting model runsFacilitates calibration and validationTIP: Create EARLY in modeling process!A VERY important step!
45 Summary ReportsThe summaries are customized using GISDK and summarize the model data in many ways, including…Facility Type and Area TypeCapacity AnalysisCongestion DelayAir Quality Emissions ResultsSummary 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.
46 ApplicationsTransCAD applications for the transportation planning and analysis process
47 Land Use and TAZ Overlay Land Use MapLand Use and TAZ OverlayTAZ Map
55 Site Selection / Geocoding Fire stationsSchool sitesPark locationsAVI – 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.
57 Travel Sheds / Critical Link Analysis Identify users of a specific facilityAnalysis for Adequate Community Facilities Ordinances and road fee programs
58 GIS-Based Transportation Improvement Programs AgencyProjectFunding AmountAnaheimLincoln Avenue Signal Coordination$52,910State College SR-91$150,000Buena ParkArtesia 1-5 Interchange$132,795Costa MesaFairview Road$29,846IrvineBicycle Program$67,200
59 Transit Planning and Operations Strategic transit planningUniversity transportation planningCorridor planningMarket identification and productivityManagement and placement of capital assets
60 Land Use / Transportation / Air Quality Conceptual 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
61 Air Quality Analysis Link-based emissions Zone-based emissions (i.e. cold starts, evaporate VOCs, etc.)Air quality conformity determinationsRedesignation and classification issuesIntegration with gridded urban airshed modelingIntegration with Mobile5
62 Land Use / Transportation / Air Quality Available from the performance summary report for the Fort Collins Nonattainment area
63 Integrated Air Quality Modeling TransCAD 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
64 GIS-Based Emissions Inventories Link-based emissionsGridded Overlay for RegionZone-based emissions
65 Intersection Analysis Intersection Flow Diagram Volumes from TransCADTraffic CountsNCHRP 255 ProcessSynchro Intersection AnalysisThere 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.SimTraffic 2D AnimationVISSIM 3D Animation
77 Construction Management Modify signal timing in response to construction closures
78 Future TransCAD Applications Interactive 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
79 LSA Associates, Inc. 132 West Mountain Avenue Fort Collins, CO 80524 The ending slide
80 Tips, Trips, and Traps of TransCAD Modeling Presented by LSA Associates, Inc.September 2001North Carolina MPO ConferenceFayetteville, NC