How To Plan A City Of Korea

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1 TRANSCAD MODELING AT NCTCOG: WHAT WE NOW HAVE For UT-Austin/NCTCOG Meeting January 28, 2004

2 AGENDA Background Modeling Environment Trip Generation And Distribution Transit Skims Mode Choice Transit And Traffic Assignment Future Issues

3 MODELING ENVIRONMENT NCTCOG-Developed FORTRAN Programs (Mainframe) MOBILE5A Emissions Analysis Latest Mobility Plan Update For Legacy Applications TRANPLAN (PC) Subarea Traffic Modeling (Legacy Applications) TransCAD (PC-Windows) MOBILE6 Emissions Analysis Future 2030 Mobility Plan All New Travel Modeling Activities

4 SOFTWARE SELECTION DECISION We Are Tired Of Maintaining/Updating Our Own FORTRAN Programs It s Difficult, Being Our Own Software Vendor! And It Costs A Lot Of Money To Rent Mainframe Time Competitive Travel Model Software Procurement Process RFP Sent To Travel Model Software Vendors (1998) Selection Committee NCTCOG, Texas DOT, DART, And City of Fort Worth Staff TransCAD Selected From The Five Submissions

5 TRANSCAD MODEL SIZE 4874 Zones Retained For ALL Modeling Steps From Trip Generation To Traffic/Transit Assignment Number Of Zone-To-Zone Pairs = 23.8 Million Year 2025: 27,000 Roadway Links + 9,600 Zone Connectors Over 36,000 Coded Links 22,000 Network Nodes 2025 Transit 410 Coded One-Way Bus Lines And 36 Rail Lines 14,500 Bus Stops And 171 Rail Stations

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8 TRAVEL DEMAND FORECASTING PROCESS Urban Activity Trip Frequency Destination Choice Mode Choice Roadway Route Choice Transit Route Choice

9 FOUR-STEP TRANSCAD MODELING PROCESS DEMOGRAPHIC INFORMATION ZONE LAYER ROADWAY NETWORK TRIP GENERATION ROADWAY SKIMS TRIP DISTRIBUTION TRANSIT NETWORK LOOP MODE CHOICE TRANSIT SKIMS ROADWAY ASSIGNMENT NO TRAVEL TIME CONVERGENCE YES INPUT PROCESS TRANSIT ASSIGNMENT DECISION

10 PROBLEMS WITH INTUITIVE FULL TRAVEL PATTERN APPROACH The Great Problem Of Data Modeling Algorithm Shortcomings Calibration Difficulties Model Maintenance Issues The Greater Problem Of Prediction Computational Power Problem

11 TRANSITION TO THE REAL WORLD Actual Scope Model Scope All Trips Motorized Trips All Purposes HBW, HNW, NHB, And Truck Purposes All Occupations Basic, Retail, Service All Households Income Size Categories All Streets Non-Local Streets Individual Data Aggregate Data Need For Adequate Samples In Household Survey RAA level In Loading The Trips TSZ level Chained Models Separate Models

12 CREATION OF 4,874-ZONE STRUCTURE Start With Year 2000 Census Block Layer GDT Rectification Some Block Splits (e.g., DFW And Love Field Airport) 76,336 Blocks Aggregated to 6,399 zones Add 61 External Station Tiny Circle Zones = 6,460 Total Zones Aggregate The 6,460-Zone Layer = 4,813 Internal Zones + 61 External Station Zones = 4,874 TAP zones

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14 MODEL RUN TIMES (FOR 3.2 GHz PC) Full No Feedback Model Run = 647 Minutes (10.8 Hours) Trip Generation = 1.0 minute Roadway Skimming (4) = 11 minutes Trip Distribution = 11 minutes Market Segmentation = 6 minutes Transit Prep And Skimming (4) = 77 minutes Mode Choice (13) = 65 minutes Matrix Preparations (For Transit Assignment) = 10 minutes Transit Assignment (4) = 21 minutes Matrix Preparations (For Traffic Assignment) = 98 minutes Traffic Assignment (3) = 347 minutes (5.8 hours)

15 TRIP GENERATION GISDK Macro Language Seven Regular Internal-Internal Trip Purposes 4 HBW, 1 HNW, 1 NHB, And 1 Truck Inputs Population, Households, Income, And Basic/Retail/Service Jobs Special Generators (Shopping Malls, Colleges, Hospitals, Airports)

16 HOUSEHOLD INCOME DISTRIBUTION Income Group Portions in Zone Total = Qrtl. 1 Qrtl. 2 Qrtl. 3 Qrtl Average Zone Income / Regional Median Income 0.11

17 HOUSEHOLD INCOME DISTRIBUTION ADJUSTMENT Enforcing 25% Of Households To Be In Each Quartile Requires Applying Iterative Proportional Fitting (IPF) To The Raw Distributed Households

18 HOUSEHOLD SIZE DISTRIBUTION Household Size portions in Zone HH1 HH2 HH3 HH4 HH5 HH Avg. Zone Household Size

19 JOINT INCOME AND HOUSEHOLD SIZE DISTRIBUTION Using The Regional Distribution As A Seed, We Create A Joint Distribution For Each Zone HH1 HH2 HH3 HH4 HH5 HH6+ QT QT QT QT

20 TRIP PRODUCTION STRATIFICATION Home-Based Work (Trips Made With Car Or Transit) 4 Income Groups And 6 Household Sizes Home-Based Non-Work (Trips Made With Car Or Transit) 4 Income Groups And 6 Household Sizes Non-Home-Based (Trips Made With Car Or Transit) 4 Income Groups And 6 Household Sizes Truck (Trips By Non-Transit Vehicles With 6 Or More Tires) 4 Employment Types (Including Household) And 5 Area Types

21 TRIP PRODUCTION RATE TABLE FOR HBW Inc.Q. Household Size

22 AREA TYPE CALCULATIONS Based On RAA-Level Calculations: b = 1.59 (Population / Employment Ratio In 1999) ad = [pop + b*(bas + ret + ser)] / landarea 30 <ad ==> Area Type = <ad<=30 ==> Area Type = <ad<=7.5 ==> Area Type = 4 ad<=1.8 ==> Area Type = 5 CBD Zones Always Considered Area Type 1 Changes Based On Being An Island And Being Close To Thresholds

23 EMPLOYMENT INCOME DISTRIBUTION The Distribution Of Employment Across Income Quartiles At Work Is Needed, To Prevent Misallocation Of Trips During Trip Distribution Income Distribution At Workplace Based On Household Income And Number Of Nearby Employees IPF Used To Adjust Distributions To Regional Ratios

24 TRIP ATTRACTION STRATIFICATION Home-Based Work 4 Income Groups, 5 Area types, And 3 Employment Types Home-Based Non-Work 4 Employment Types (Including Household) And 5 Area Types Non-home-based 4 Employment Types (Including Household) And 5 Area Types Truck 4 Employment Types (Including Household) And 5 Area Types

25 TRIP BALANCING HBW Productions Balanced To Attractions HNW Attractions Balanced To Productions NHB Attractions Balanced To Productions And Then For Each Zone Production Is Set To Equal Attraction Truck Attractions Balanced To Productions

26 DEMOGRAPHICS FOR SPECIAL GENERATORS Current Special Generators Regional Shopping Malls With Over 500,000 Square Feet (20) Colleges/Universities With Over 1,500 Enrolled Students (27) Hospitals With Over 300 Service Employees (42) DFW And Love Field Airport Terminals (Special Treatment) Special Input Data Fields (e.g., For Shopping Malls) SGRETAIL = Number of Jobs In Zone That Relate To The Shopping Mall SGUNIT = Total Leasable Square Footage (Thousands Of Square Feet) HBW, HNW, NHB, And Truck Trip Rates Per Thousand Square Feet

27 EXTERNAL STATION TRIP TABLES Internal-External And External-Internal (IE/EI) Weekday Passenger Vehicles (Total Trip Ends) External-External (EE) Weekday Passenger Vehicles IE/EI Weekday Trucks (Six Or More Tires) EE Weekday Trucks (Six Or More Tires)

28 TRIP DISTRIBUTION Gamma-Format Gravity Model (7 Purposes) Four HBW Groups (Income Quartiles) AM Peak HNW (Non-Airport) -- OffPeak NHB (Non-Airport) -- OffPeak Trucks (Vehicles With Six Or More Tires) -- OffPeak Base Year Trip Table Factoring (6 Purposes) HNW And NHB Airport Trips Four External-Related Auto/Truck Trips

29 ZONE TO ZONE SKIM TABLES FOR MODE CHOICE Four AM Peak Skims (6:30a 8:59a) Roadway Without HOV Links Available (Drive Alone) Roadway With HOV Links Available (Shared Ride 2 And 3+) Transit Drive Access (PA Format) Transit Walk Access (PA Format) Four OffPeak Skims Roadway Is 18-hour Offpeak Without HOV Links Available (Drive Alone) With HOV Links Available (Shared Ride 2 And 3+) Transit Is 6-hour Mid-Day Offpeak (9:00a 2:59p) Drive Access (PA Format) Walk Access (PA Format)

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37 Auto Travel MODE CHOICE INPUTS Roadway Travel Time Roadway Length (Operating Cost) Daily Parking Cost Transit Travel In-Vehicle Transit Travel Time (Includes Dwell) Walk (Or Drive) Access Time Walk Transfer And Egress Time Initial And Transfer Wait Time Transit Fare Market Segment And Area Type Constants

38 MARKET SEGMENTATION Objective: To Account For Differences In Commuter Behavior Segmentation Basis (For HBW And HNW) Household Income (3) Low Medium High Vehicle Availability For A Household (2) Vehicles Less Than Persons Vehicles Greater Than Or Equal To Persons

39 HBW MODE CHOICE: MAINFRAME VS TRANSCAD Choice Drive Alone Shared Ride 2 Shared Ride 3+ Transit Drive Transit Walk Choice Auto Transit Drive Transit Walk Drive Alone Shared Ride 2 Shared Ride 3+

40 HNW MODE CHOICE: MAINFRAME VS TRANSCAD Choice Drive Alone Shared Ride 2+ Transit Drive Transit Walk Choice Drive Alone Shared Ride Transit Shared Ride 2 Shared Ride 3+ Transit Drive Transit Walk

41 NHB MODE CHOICE: MAINFRAME VS TRANSCAD Choice Drive Alone Shared Ride 2+ Transit Drive Transit Walk Choice Drive Alone Shared Ride 2 Shared Ride 3+ Transit Drive Transit Walk

42 POST MODE CHOICE 13 Market Segments 5 Mode Shares Trucks (From Trip Distribution) PA To OD Time Of Day Factoring And Aggregation Vehicle Trip Table Factoring

43 TRANSIT ASSIGNMENT Four Multi-Path (Pathfinder) Production-Attraction Assignments For All HBW Transit Trips Peak Transit-Initial Drive Access (Park-and-Ride) Peak Transit-Initial Walk Access (No Park-and-Ride) For All HNW And NHB Transit Trips Offpeak Transit-Initial Drive Access (Park-and-Ride) Offpeak Transit-Initial Walk Access (No Park-and-Ride)

44 TRAFFIC ASSIGNMENT PREPARATION Trip Table Aggregation AM Peak Period (2.5 Hours) PM Peak Period (3.5 Hours) OffPeak Period (18 Hours) K Factoring Compensate For Gravity Model Limitations OD Estimation Procedure To Help With Identification Adjustments/Checks Based On Screen Line Results

45 TRAFFIC ASSIGNMENT User Equilibrium Generalized Cost (Three 30-Iteration Assignments) A.M. Peak (6:30a 8:59a: 2.5 hours) P.M. Peak (3:00p 6:29p: 3.5 hours) OffPeak (18 hours) Four Vehicle Classes Loaded Simultaneously Drive Alone Shared-Ride Sees HOV Lanes Shared-Ride Doesn t See HOV Lanes Trucks (Vehicles With 6 Or More Tires)

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47 SPEED VS V/C RATIO Speed (mph) V/C Ratio Assignment Speed Post Process Speed

48 POST-PROCESSING OF LINK SPEEDS Example: AM Peak Directional Link Speeds Allocate (Based on ATR Factors) The 2.5-Hour AM Peak Assignment Volume Into Three Sub-Periods 6:30a 6:59a 7:00a 7:59a 8:00a 9:00a Calculate V/C ratios For Each Sub-Period Note: Capacity for 30-minute period is ½ the hourly capacity Apply The Post Process Volume Delay Curves

49 TRAFFIC MODEL LIMITATIONS (First Page) Ideally, the congested speeds directly from traffic assignment should be used in trip distribution but we post process because the calibrated parameters do not give us realistic speeds A low C parameter in the volume-delay equation (maximum minutes of delay per mile) has important implications for high-congestion scenarios Related to above: Peak Spreading is not directly considered; in the future, we may consider peak hour and shoulder of the peak assignments

50 TRAFIC MODEL LIMITATIONS (Second Page) The Offpeak assignment represents 18 hours of the day perhaps a future breakdown into Mid-Day Offpeak (9:00 a.m. 2:59 p.m.) and Evening/Night Offpeak (6:30 p.m. to 6:29 a.m.) We have no observed data to directly calibrate HOV-Toll usage; instead, we have to rely on our calibrated sharedride trip table HOV/NoHOV factoring and toll road value of time modeling The HOV/NoHOV factoring procedure is just one way of making things work Special link impedances could also have been used

51 TRAFFIC MODEL LIMITATIONS (Third Page) All passenger vehicles are assumed to have the same value of time Trucks (By Our Choice) are given a Passenger Car Equivalency of 1.0 Real link capacities are more complex than our look-up tables CAUTION on number of UE assignment iterations: complete closure is NOT practical!

52 AUTOMATED NETWORK CONVERSION

53 WHAT HAPPENS NEXT FOR NCTCOG One Key To Good Modeling Is The Quality Of The Overall Information System Improvements/Updates To Modeling Procedures Expansion Of The Modeled Area Destination Choice Instead Of Gravity Model Trip Distribution LOGSUM Consistencies New Travel Surveys In 2006 Activity-Based Implementation (After Full Testing!) Traffic Microsimulation TransCAD Subarea Analysis To Create Windowed OD Table Dallas CBD Project Underway (Using VisSim)