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Development of The Tennessee Statewide Travel Demand Model. G. P. L. A. N. o. D. T. T. A Long-Range Multimodal Strategy. Presented By:. Presentation Agenda. General Model Design. Highway Network/Traffic Analysis Zones (TAZs). Review. Development of Synthetic Trip Tables.
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Development of The Tennessee Statewide Travel Demand Model G P L A N o . D T T A Long-Range Multimodal Strategy Presented By:
Presentation Agenda General Model Design Highway Network/Traffic Analysis Zones (TAZs) Review Development of Synthetic Trip Tables Validation Procedures & Results Model Application (2003 & 2030)
General Model Design Model Characteristics • Address Major Corridor Movements • Relatively Easy to Maintain and Update • Uses Existing Data Resources • Uses Existing Software for Application • Links to Existing GIS Databases/Software • Sensitive to Shifts in Socioeconomic/Land Use Patterns • Assess Impacts of Shifts in Travel Modes • Assess Freight Movements
General Model Design Potential Methodologies • Traditional Four Step TDM Procedures • Trip Generation • Trip Distribution • Mode Choice • Traffic Assignment • Trip Table Expansion (FRATAR) • Preparation of Base Trip Table(s) • Development of Expansion Factors
General Model Design Steps In Model Development • Development of Highway Network & TAZs • Selection of Detail for Highway Network • Definition of TAZs • TAZ/Network Compatibility • Synthetic Matrix Estimation (SME) • Development of Seed Matrices • Matrix Estimation • Traffic Assignment
Highway Network/TAZs Network/TAZ Definition • Incorporate All Roadways in TRIMS • 1,283 Miles of Interstate/Freeways • 4,300 Miles of Principal Arterials • 8,271 Miles of Other • Subset of TRIMS • Interstate and Freeways • Principal Arterials
Highway Network/TAZs TRIMS/Model Comparison
TAZ Boundary Highway Network/TAZs REGION 1 Network/TAZs
TAZ Boundary Highway Network/TAZs REGION 2 Network/TAZs
TAZ Boundary Highway Network/TAZs REGION 3 Network/TAZs
TAZ Boundary Highway Network/TAZs REGION 4 Network/TAZs
Highway Network/TAZs National Network
Synthetic Trip Table Development Background • Trip Tables Are One of the Basic Elements of Travel Demand Models • Origin-Destination (O-D) Surveys Traditional Method for Trip Table Development • Developing Trip Tables Using Traffic Counts has been Source of Research for Past 30 Years
Synthetic Trip Table Development Required Inputs • Traffic Counts • Traffic Assignment Network • Seed Trip Table
Synthetic Trip Table Development Required Inputs – Traffic Counts • Sample should come from widely dispersed parts of the network • Counts on Selected Links and on Screenlines/Cutlines • Counts Need to be Directional
Synthetic Trip Table Development Required Inputs – Traffic Assignment Network • Traffic Assignment Network MUST Produce Realistic Results • Equilibrium Assignment Process
Synthetic Trip Table Development Required Inputs – Seed Matrix Potential Sources of Seed Matrix • Default matrix • Prior estimate based on survey measurements • Synthetically generated (e.g., from a doubly-constrained trip distribution model)
Synthetic Trip Table Development Seed Matrix • Serves Two Purposes • Set the dimensions for the output matrix • Provide initial values for the estimated trip table • O-D Matrix Estimation only accounts for trips between zones (diagonal cells will be ignored – trips within a zone) • Every cell that is expected to have a positive flow must have a positive number in the base matrix
Synthetic Trip Table Development Seed Matrix • Three Trip Purposes Used • Work • Other • Non-Home Based • Used Trip Rates and Lengths From National Household Survey • Urban • Rural
Synthetic Trip Table Seed Matrix Seed Matrix – Trip Generation 2001 NHTS Database ● HBW – 1.70 trips/household ● HBO – 3.20 trips/household ● NHB – 2.65 trips/household ● Total – 7.55 trips/household
Synthetic Trip Table Seed Matrix Seed Matrix – Trip Distribution 2001 NHTS Trip Length Distribution - HBW
Synthetic Trip Table Seed Matrix Seed Matrix – Trip Distribution 2001 NHTS Trip Length Distribution - HBO
Synthetic Trip Table Seed Matrix Seed Matrix – Trip Distribution 2001 NHTS Trip Length Distribution - NHB
Synthetic Trip Table Seed Matrix Seed Matrix – Initial Matrix • Not Person Trips; • Merging of HBW, HBO, NHB, Internal-External and External-External Trip Tables; • Seed Matrix represents Passenger Cars and Light Commercial Vehicle Trips Only; and, • Additional Intercity (MPO to MPO) vehicle trips were added in relation to 2000 CTPP Place of Residence and Place of Work Information.
Base Year (2003) Synthetic Trip Table • Traffic Counts • Traffic Assignment Network • Seed Trip Table • Application of TransCAD Matrix Estimation Program
Trip Table Evaluation Good ? NO YES Base Year (2003) Trip Table Matrix Estimation Applicaiton Application of TransCAD Matrix Estimation Program Input Adjustments: Network Seed Table Counts
Matrix Estimation Applicaiton Matrix Evaluation Parameters • Trip Length • Goodness of Fit • Screenlines
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Auto Model Validation Procedures Screenline Results – Region 1
Auto Model Validation Procedures Screenline Results – Region 1
Auto Model Validation Procedures Screenline Results – Region 1
Auto Model Validation Procedures Screenline Results – Region 1
Auto Model Validation Procedures Screenline Results – Region 1
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Auto Model Validation Procedures Screenline Results – Region 2
Auto Model Validation Procedures Screenline Results – Region 2
Auto Model Validation Procedures Screenline Results – Region 2
Auto Model Validation Procedures Screenline Results – Region 2
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Auto Model Validation Procedures Screenline Results – Region 3
Auto Model Validation Procedures Screenline Results – Region 3
Auto Model Validation Procedures Screenline Results – Region 3
Auto Model Validation Procedures Screenline Results – Region 3
Auto Model Validation Procedures Screenline Results – Region 3
Auto Model Validation Procedures Screenline Results – Region 3
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