Kentucky Statewide Travel Model (KYSTM) Rob Bostrom Wilbur Smith Associates Combined Kentucky-Tennessee Model Users Group Meeting Bowling Green, KY October 26, 2006
Presentation Overview Overview of statewide model synthesis Kentucky s statewide model history Overview of recent Kentucky statewide model development
Statewide Travel Forecasting Study origins Suggested by this committee Models NCHRP studies: http://www4.trb.org/trb/crp.nsf/reference/appendices/nchrp+overview Panel members TRB Program Manager Jon Williams Other: G. Giamio, R. Bostrom, J. Dunbar, H. Shen, D. Hunt, B. Gorman,B. Upton, M. Duross, H. Miller Schedule Selection meeting in winter, 2005 in D.C., selected Alan Horowitz of UWM Draft review meeting in July, 2005 in O.C. Final draft in editorial process
Study Highlights Survey of Statewide Travel Forecasting Practice Rural forecasting States doing statewide modeling Rationale Barriers Hardware/software Model usages Passenger/freight LU/Economic activity Statewide/urban integration Validation Post-processing Case Studies: KY, IN, OH, VA, WI Findings and Research Recommendations
Methodology Peer Exchange Reporthttp://www.dot.state.oh.us/urban/Download.htm Surveys Screening questionnaire sent to all states Full questionnaire for states not participating in the Peer Exchange
Passenger Models Wide range of approaches Integrated models Ohio Oregon
Freight Models Trend towards commodity based, e.g. WI Generation Total Tons Distribution Tons by O-DO Truck Shares & Payloads O-D D Trucks Truck Assignment Trucks by Route
Findings Recent evolution of Statewide Travel Forecasting Models Network detail, commodity based freight, GIS networks, equil. assn.s Challenges ATS not updated, 24-hr. assn.s, transferable parameters not developed, little integration of urban/statewide, county-level data still used Recent Innovative Efforts Nested zone structures, integration of freight/passenger/econ., tourbased components,
Recommendations Four main research recommendations (from Peer) Rural Area Trip-making characteristics Development of a national passenger travel model Development of validation performance standards Long distance travel data collection State of practice suggests: Improvements in traffic assignment Intermodal freight networks Better info for non freight commercial vehicles Better public source commodity flow info Innovative means of ODME Improved curricula for trans. Planning graduate programs
Kentucky s Statewide Model History First model (1975) Study design by Alan Voorhees Planpac Work performed in-house Used for system needs Second model (1991) Limited update Features: triptable, in-state zones, MinUTP WSA performed work
Kentucky s Statewide Model Third model (1996) History Expanded zone system (1400 total, 700 in-state) First attempt at truck modeling, used matrix estimation Data sources: NPTS, Census, Transearch Impetus for model: I-66 Corridor Study Software: MinUTP Vendor: WSA 1999 corridor validation for additional I-69 study & new I- 66 alternatives
Kentucky s Statewide Model History Current model (2006) Expanded zone system (4870 total, 3651 in-state) Improved truck modeling, based on commodity flows Data sources: NPTS, Census, Transearch Impetus for model: corridor studies, freight needs, input from Stakeholder Meeting Software: TransCAD Vendor: WSA
Kentucky s Statewide Model Current model (2006) Combined zone system (2002) Version 1.0 Version 2.0 Future Enhancements Freight Interface History
2006 KYSTM: Goal Statement to develop a set of computerized mathematical and data management procedures ( model ) that will: Replicate existing intercity car and truck movements on major roads in Kentucky. Forecast alternative intercity car and truck movements likely to occur Generate reproducible model outputs, that can be easily understood Does not try to replicate volumes in urban areas.
Intercity not intracity
Model Framework Two inter-related models were used to forecast statewide traffic: A Macro Model covering all 48 contiguous states. 100,579 miles of total highway miles A Micro Model covering only Kentucky but at a much more detailed level than the Macro Model. 27,874 miles of KY highway miles 1,490 miles of double-lined routes 406 miles of ramps The two models are integrated.
Macro Model Network
Micro Model Network
Model Framework The Macro Model forecasts longer distance auto and truck travel to, from, through and within Kentucky. The Micro Model forecasts shorter distance auto and truck travel within Kentucky. The Final Model integrates both types of trips and forecast total auto, total truck, and total vehicle travel within Kentucky.
Trip Categories Truck Trips Long Distance Truck Trips Local Truck Trips Private Occupancy Vehicles (POV) Trips Short distance (<100 miles) Home Based Work (HBW) Home Based Other (HBO) Non Home Based (NHB) Long Distance Business Tourist Other
Truck Trips Base Year Long Distance Truck Trips Source: Transearch Database. Disaggregate County/BEA level data to Zone level using employment. (for each STCC) Convert Tons to Trucks. Local Truck Trips Calculated using an ODME procedure in order to calibrate to Truck Counts.
Truck Trips
HBW Trips Base Year Coverage: Intrastate and Interstate with one end in Kentucky Sources: Census Journey to Work data 2001 NHTS Methodology: Developed cross classification trip generation rates (Claritas Area Type and MSA Size) from NHTS and TransCAD QRM regression equations. Distributed based on the JTW data.
HBO and NHB Auto Trips Base Year Source: 2001 National Household Travel Survey (NHTS) Methodology: Developed trip generation rates. Distributed using Gravity Model. Includes HBO and NHB auto trips to and from adjacent counties. (External Stations) Eliminated any trip > 100 miles. Developed K Factors during calibration. Developed average auto occupancy from NHTS. Apply to obtain auto trip tables for HBO and NHB.
Long Distance POV Trips Base Year Coverage: Interstate Auto trips to, from, and through Kentucky and long distance intrastate auto trips. Purposes: Business, Tourist, Other. Sources: 1995 American Travel Survey (ATS). Methodology: Interstate: Expand ATS to develop 1995 trip tables. Intrastate: Expand ATS to develop 1995 trip tables. Verify that trip length > 100 miles. Develop growth factors based on socio-economic growth and fratar to 2003.
Traffic Assignment Base Year Assign trucks first using All or Nothing (AON) Assign all POV together using User Equilibrium (UE) Preload Trucks. Use calculated capacity. Use standard BPR curve to adjust for congestion.
Calibration Results Base Year 1. VMT Comparison (count vs. estimated) by Rural Functional Class Total Traffic 2. Screenlines Results Total Traffic 3. Screenlines Results Truck Traffic 4. NCHRP Curve (Percent Deviation) 5. VMT Comparison (count vs. estimated) by Rural Functional Class Truck Traffic
VMT Comparison ( count vs. estimated) NO. LINKS WITH V M T VMT DISTRI. AVERAGE VOLUME_ ----------------- COUNT NO CNT COUNT ----------------- VMT % ----------- -------------- % FC COUNT NO CNT MILES MILES % COUNTED ESTIMATED ERROR CNT. EST. COUNTED ESTIMT RMSE RMSE 1 104 1654 442 815 35.2 7422464 7678222 3.4 22.5 25.3 18000 18343 2347 13.0 2 460 2772 989 1605 38.1 5552458 5334927-3.9 16.8 17.6 7770 7185 1703 21.9 6 378 2602 386 1249 23.6 1593559 1485627-6.8 4.8 4.9 4707 4322 1290 27.4 7 1607 9004 1920 5012 27.7 3914059 3587907-8.3 11.9 11.8 2534 2269 945 37.3 8 957 10133 1199 8297 12.6 1055946 930095-11.9 3.2 3.1 1102 958 608 55.2 9 239 5196 224 3705 5.7 120136 111358-7.3.4.4 714 667 389 54.5 ----------------------------------------------------------------------------------------------------- RUR 3745 31361 5161 20681 20.0 19658622 19128138-2.7 59.6 63.1 3344 3089 1079 32.3 ----------------------------------------------------------------------------------------------------- 11 90 1769 118 512 18.7 4180816 3668940-12.2 12.7 12.1 43386 37205 12824 29.6 12 51 312 48 117 29.1 785160 603579-23.1 2.4 2.0 16364 12351 8031 49.1 14 617 2571 223 450 33.1 4656788 4544725-2.4 14.1 15.0 19609 20834 14347 73.2 16 848 3560 295 631 31.9 3146262 2114617-32.8 9.5 7.0 10895 7818 6898 63.3 17 248 1123 105 306 25.6 499546 246225-50.7 1.5.8 5052 2966 5146 101.9 19 54 359 19 91 16.9 40603 24918-38.6.1.1 2499 1667 2879 115.2 ----------------------------------------------------------------------------------------------------- URB 1908 9694 809 2107 27.7 13309177 11203008-15.8 40.4 36.9 14394 12730 10043 69.8 ----------------------------------------------------------------------------------------------------- TOT 5653 41055 5969 22788 20.8 32967798 30331146-8.0 100.0 100.0 7074 6343 5900 83.4 -----------------------------------------------------------------------------------------------------
Screenline Locations
Screen Lines Validation Summary ---------------------------------------------------------------------------------------------------------------- SCREEN NO.COUNT COUNT V O L U M E E R R O R TRK CNT TRUCK VOLUME TRUCK ERROR TOTAL TOT EST. LINE LINKS % COUNTED ESTIMATED DIFF. PERCENT LINKS COUNTED ESTIMATED DIFF. PERCENT LINKS VOLUME --------------------------------------------------------------------------------------------------------------- 1 15 100.0 117960 110563-7396 -6.3 5 24338 24451 113.5 15 110563 --------------------------------------------------------------------------------------------------------------- 2 7 100.0 101900 109679 7779 7.6 4 1753 2396 643 36.7 7 109679 --------------------------------------------------------------------------------------------------------------- 3 17 100.0 59154 52277-6876 -11.6 4 1685 2426 741 44.0 17 52277 --------------------------------------------------------------------------------------------------------------- 4 18 100.0 81913 77525-4387 -5.4 10 17807 18656 849 4.8 18 77525 --------------------------------------------------------------------------------------------------------------- 5 28 100.0 89913 99472 9559 10.6 7 15871 16307 436 2.7 28 99472 --------------------------------------------------------------------------------------------------------------- 7 12 100.0 53593 49914-3678 -6.9 7 9415 9582 167 1.8 12 49914 --------------------------------------------------------------------------------------------------------------- 9 28 100.0 36275 35958-316 -.9 9 2996 2940-55 -1.9 28 35958 --------------------------------------------------------------------------------------------------------------- 10 34 100.0 148474 152650 4176 2.8 15 27898 28562 664 2.4 34 152650 --------------------------------------------------------------------------------------------------------------- 11 13 100.0 73941 71751-2189 -3.0 7 14904 14884-19 -.1 13 71751 --------------------------------------------------------------------------------------------------------------- 12 9 100.0 52379 49925-2453 -4.7 4 4057 3888-168 -4.2 9 49925 --------------------------------------------------------------------------------------------------------------- 14 9 100.0 102200 99930-2269 -2.2 7 9118 9299 181 2.0 9 99930 --------------------------------------------------------------------------------------------------------------- 15 26 100.0 92540 93144 604.7 11 21924 22233 309 1.4 26 93144 --------------------------------------------------------------------------------------------------------------- 16 25 100.0 47045 47092 47.1 4 3057 2561-495 -16.2 25 47092 --------------------------------------------------------------------------------------------------------------- 17 28 100.0 68400 62964-5435 -7.9 6 3228 3298 70 2.2 28 62964 --------------------------------------------------------------------------------------------------------------- 18 31 100.0 85009 82264-2744 -3.2 16 10372 10971 599 5.8 31 82264 --------------------------------------------------------------------------------------------------------------- Total 300 100.0 1210696 1195108-15587 -1.3 116 168423 172454 4031 2.4 300 1195108 ---------------------------------------------------------------------------------------------------------------
Percent Deviation For Rural Links in Kentucky 100.0% 90.0% 80.0% 70.0% Percent Deviation 60.0% 50.0% 40.0% Maximum Desirable Deviation 30.0% 20.0% 10.0% 0.0% - 10.0 20.0 30.0 40.0 50.0 60.0 Counts (Thousands)
Future Year Model Highway Network: Can use existing network. (current approach) Modify network to incorporate existing plus committed highways. (E+C) Others Trip Tables: Most changes due to change in socio-economic (SE) data. User can use alternative SE forecasts.
Truck Trip Table Forecast year Developed growth factors at each zone origin and each zone destination for each STCC truck trip table and local truck trip table and applied Fratar procedure. Combined into one future (2030) LD Truck Trip Table. Intermediate years are forecasted by interpolation. Note: Truck trips are not sensitive to alternate SE forecast
HBW Trip Table Forecast Year Estimate growth for each zone based on household (origin) and total employment (destination) forecasts. Apply Fratar procedure to base year HBW person trip table in PA format. Balance and convert to vehicle trip table.
HBO and NHB Trip Tables Forecast Year Apply same methodology as base year: Trip generation using forecast year socio-economic data. Trip distribution using time from future network. Eliminate trips > 100 miles. Balance and convert to vehicle trip tables.
Long Distance Auto Trip Tables Forecast Year Estimate growth for each zone (one for origin, one for destination) based on socio-economic forecasts. Uses different socio-economic data depending on trip purpose. For example: Business trip Uses population growth for origin. Uses total employment growth for destination. Apply Fratar procedure to base year PA person trip tables by purpose. Balance and convert to vehicle trip tables.
Traffic Assignment Forecast Year Assign trucks first using All or Nothing. (AON) Assign all POV together using User Equilibrium. (UE) Preload Trucks. Use calculated capacity. Use standard BPR curve to adjust for congestion.
User Interface
User Interface
Questions? Rob Bostrom 859-254-5759 & RBostrom@WilburSmith.com Sashank Singuluri 803-251-2195 & Ssinguluri@wilbursmith.com Anne Reyner 803-251-2037 & AReyner@wilbursmith.com