Tips, Trips, and Trapsof TransCAD Modeling LSA Associates, Inc. September 2001 North Carolina MPO Conference Agenda 2 Why Model? Why Jurisdictions Convert to TransCAD? The Transportation Model GIS Developer’s Kit Applications Why Model? Why do we model the transportation network? Why Model? 4 To consider the effects of land use, transportation, and air quality To determine infrastructure needs, costs, and timing as growth occurs To analyze land use and transportation alternatives To provide a consistent platform for travel forecasting Required by the federal government for metropolitan areas The History of Travel Forecasting Aggregate Models 50’s 60’s and 70’s 80’s and 90’s 00’s 5 Few zones Major highway planning only Computers available to large agencies Computer chip technology advances Federal government sponsorship Travel behavior surveys widespread Basic transit capability Shift to microcomputers More zones Detailed transit and HOV models Windows-based More disaggregation and detail GIS-based models Microsimulation . 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 required Limited capabilities in 7 Graphics Memory GIS Network size Number of TAZs . TransCAD Users There are many states in America that currently use TransCAD 8 . dbd Files .Geographic Information Systems A GIS-based transportation model Compatible with other GIS tools Spatial Analysis ArcView Shape Files 9 TransCAD *. Why TransCAD? 10 A powerful modeling software that can enhance the modeling process Windows-based menus that are intuitive to manipulate A GIS software with transportation modeling capabilities No internal size limitations Scenario manager for easy file management Ability to easily analyze intermediate results Mapping and visualization tools designed for GIS and transportation applications TIP: Choose a powerful computer! . The Transportation Model What is involved with a travel demand model? . Modeling Process Socioeconomic Data Trip Generation How many trips? Roadway Network Trip Distribution Where will they go? Transit Network Mode Analysis Traffic Assignment 12 Roadway Volumes What mode? Transit Assignment Performance Report What route? Transit Ridership Identify needs Alternatives analysis . etc. created in GISDK . File names are easy to change in the model structure with the scenario manager. locations.TransCAD Inputs Easy to understand file structure 13 No restrictions on file names. TransCAD Outputs 14 Checking intermediate modeling results is easy in TransCAD Identifying results from an individual project area allows detailed study of the project Performance module allows consistent reporting of results . Data and Databases Geographic data Network data Attribute data TransCAD model data 15 Socioeconomic data US Census data Jurisdictional boundaries Zip codes Railroads Water Features Tiger Streets Files . 16 . 17 . and any other data Multi-year network capability TIP: Keep raw count data and adjustments in traffic count database . transit. performance.Networks 18 Networks are GIS databases Conflation to GIS distances and shapes Foundation for traffic counts. Networks Transit Routes Traffic Counts Roadway System GIS Networks Performance Air Quality Project Selection (TIP/RTP) 19 Time of Day Volumes . 20 . 21 . Traffic Analysis Zone Data 22 Zonal areas used in modeling trips Ability to incorporate census data Used for summaries and reports Used for visually verifying data . Socioeconomic Data 23 Interface with popular GIS platforms Land use to socioeconomic conversion using TransCAD’s GIS tools Visual representation of land use and socioeconomic data TAZ coverage provides foundation for areabased data and is easily modified TIP: Socioeconomic sub-model can use a Fratar process coded in GISDK . Socioeconomic Data and TAZ Structure 1998 Socioeconomi c Data Area Type 2020 Socioeconomi c Data GIS TAZ Structure Performance and Air Quality Area based Indexes Terminal Penalties 24 K Factors . 25 . without compromising model structure. This ensures a full running model from start to finish. .Trip Generation 26 Robust cross classification production model Unlimited trip purposes Production allocation and attraction allocation models TIP: Include all modeling steps in TransCAD using GISDK. Trip Generation Incorporate land use data Detailed trip purposes Distance-based allocation models Special generators 27 Universities Hospitals Amusement parks Event centers Malls Government installations . 28 . 6 Friction factors – calibrated curves versus lookup table .Trip Distribution 29 TIP: Geocode survey data in house to determine trip lengths Desire lines between TAZs and districts TRIP: GISDK standard gravity evaluation procedure does not correctly apply K factors in version 3. Mode Analysis 30 Customized nested logit and multinomial logit models TIP: Don’t be limited to standard TransCAD procedures. create exactly what you want with GISDK Distance-based bike and pedestrian equations . Nested Logit Structure Person Trips Motorized Non-Motorized Drive Alone DA Non Toll Non HOV Non Toll DA Toll Shared Ride SR2 Non HOV SR2 HOV Auto Passenger SR3 Non HOV SR3 HOV Non HOV Toll Auto Express Express Non HOV Non Toll HOV Non Toll Transit Urban Rail Auto Local Walk Local Urban Rail Commuter Rail Commuter Rail Non HOV Toll HOV Toll Express HOV Non Toll 31 Walk Express HOV Toll . Traffic Assignment Time of day User defined volume-delay equations Speed post-processing Speed feedback 32 AM peak – congested speeds Off peak – freeflow speeds All or nothing. capacity constrained assignments with comparison . TransCAD Transit Capabilities 33 Walk access vs drive access Unlimited number of modes Unlimited number of variables Stops dependent upon individual routes . or by mode Drive or walk access assignment Transit flows by link Transit line volumes . by route.Transit Assignment 34 Transit boardings by stop. Validation 35 Screenlines – GIS line layer created quickly TRIP: One way links confuse the built-in screenline analysis functions . 36 . TRIP: Need to adjust for software differences.Model Conversion Process Existing Model TRIP: 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. Performance Reporting Initial Model Conversion (Caliper or LSA) Network Conflation and Model Replication Model Enhancements Calibration / Validation 37 . GIS Developer’s Kit The endless possibilities with the TransCAD programming language . TransCAD Scripting Capability 39 GISDK is the TransCAD programming language Allows for complete automation of the modeling process unique to each model Eliminates user error by programming all steps and variables in a model run Similar to programming in C++ (with different syntax and commands) Use the programming editor of your choice to create and edit the GISDK script TIP: Boxer Software is a good (and inexpensive) programming editor . Model User Interface 40 The dialog boxes that run the whole model Reduce errors by eliminating point/click/type commands GISDK is the key to programming the model . and summary reports TIP: These really help the consistency and accuracy of the model! .TransCAD Dialog Boxes 41 Custom user interfaces created using GISDK Fully automates the model procedures – including file names. variables. Scenario Manager 42 Created using GISDK Manages all files related to each alternative . GIS Developer’s Kit (GISDK) 43 Program exactly what we want TransCAD to do Allows for any mathematically sound method or procedure Not confined to standard TransCAD procedures Full dialog box customization . Performance Reporting The possibilities available for performance reporting . Performance Module 45 Provides consistent and convenient summary reports Created with GISDK Customized to the client’s needs Analysis tool for troubleshooting model runs Facilitates calibration and validation TIP: Create EARLY in modeling process! . including… 46 Facility Type and Area Type Capacity Analysis Congestion Delay Air Quality Emissions Results .Summary Reports The summaries are customized using GISDK and summarize the model data in many ways. Applications TransCAD applications for the transportation planning and analysis process . Land Use and TAZ Overlay Land Use Map TAZ Map 48 Land Use and TAZ Overlay . I-25 Socioeconomic Data Analysis 49 1998 Data 2020 Data Land Use Data . I-25 Corridor Analysis 50 1998 Data 2020 Data Land Use Data . Supply and Demand Analysis 51 Demand Supply Difference . Colorado Springs Alternatives Analysis 52 . Buffer Analysis Mile Buffer 53 Travel Time Buffers . Traffic Impact Analysis 54 Trip Distribution for a proposed development . Traffic Impact Analysis 55 . Site Selection / Geocoding 56 Fire stations School sites Park locations . Site Selection / Geocoding 57 . Travel Sheds / Critical Link Analysis 58 Identify users of a specific facility Analysis for Adequate Community Facilities Ordinances and road fee programs . GIS-Based Transportation Improvement Programs Agency 59 Project Fundin g Amoun t Anaheim Lincoln Avenue Signal Coordination $52.910 Anaheim State College Blvd @ SR-91 $150.795 Costa Mesa Fairview Road $29.000 Buena Park Artesia Blvd @ 1-5 Interchange $132.200 .846 Irvine Bicycle Program $67. Transit Planning and Operations 60 Strategic transit planning University transportation planning Corridor planning Market identification and productivity Management and placement of capital assets . VMT growth Air quality and emissions inventory On-road mobile emissions estimation 61 Stationary and mobile sources Mobile5 Nonattainment area Energy and fuel consumption .Land Use / Transportation / Air Conceptual level analysis of LUTRAQ Quality relationship Comprehensive plan updates Triggers – population vs. evaporate VOCs.Air Quality Analysis 62 Link-based emissions Zone-based emissions (i. cold starts.e.) Air quality conformity determinations Redesignation and classification issues Integration with gridded urban airshed modeling Integration with Mobile5 . etc. Land Use / Transportation / Air Quality 63 Available from the performance summary report for the Fort Collins Nonattainment area . time of day. vehicle miles of travel. emission factors. …) Emission Factor (grams per mile) TransCAD Travel Demand Model 80 70 60 50 40 30 20 10 0 3 9 15 21 27 33 39 45 51 57 63 69 75 Speed (mph) Emissions from On-Road Vehicles 64 . fuel characteristics. …) (temperatures.Integrated Air Quality Modeling EPA Mobile/Part Emissions Models (speeds. GIS-Based Emissions Inventories Link-based emissions Gridded Overlay for Region Zonebased 65 emissions . Intersection Analysis Intersection Flow Diagram Volumes from TransCAD Traffic Counts NCHRP 255 Process Synchro Intersection Analysis 66 SimTraffic 2D Animation VISSIM 3D Animation . TransCAD Turn Movement Forecasts 67 . 68 . SimTraffic MicroSimulation 69 . VISSIM Micro-Simulation 70 . VISSIM Micro-Simulation 71 . VISSIM Micro-Simulation 72 VISSIM Micro-Simulation 73 VISSIM Micro-Simulation 74 VISSIM Micro-Simulation 75 VISSIM Micro-Simulation 76 . VISSIM Micro-Simulation 77 . Construction Management 78 Modify signal timing in response to construction closures . Future TransCAD Applications 79 Interactive MPO Project Prioritization and Funding Allocations Traffic Impact Studies: Cumulative improvements and impacts. time of day project distributions FHWA TDM Model Mixed Use Activity Center Trip Generation & Distribution Bicycle Assignments Transportation Corridors Pavement Management . com .ftcollins@lsaassoc. CO 80524 970.494. Inc.LSA Associates.1568 lsa. 132 West Mountain Avenue Fort Collins. Tips. NC . Trips. Inc. September 2001 North Carolina MPO Conference Fayetteville. and Traps of TransCAD Modeling Presented by LSA Associates.