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Presentation to FDOT SPO 23 March 2011 Heinrich McBean. Incorporating Time of Day Modeling into FSUTMS – Phase II. Time of Day (Peak Spreading) Model. Background. Identified as a top priority by Model Task Force in 2008 Research project divided into two phases
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Presentation to FDOT SPO 23 March 2011 Heinrich McBean Incorporating Time of Day Modeling into FSUTMS –Phase II Time of Day (Peak Spreading) Model
Background • Identified as a top priority by Model Task Force in 2008 • Research project divided into two phases • Phase I: Fixed TOD Factoring and Procedure Development • Phase II: Development and implementation of TOD peak spreading model.
Why Consider Time of Day Modeling • Time at which travel occurs vary by time of day and location • Variation results in peaking of demand during weekday AM and PM work commute • Knowledge of period travel demand provides useful insights for planning and operations Source: FHWA, Our Nation’s Highway, 2010
Why Incorporate TOD in FSUTMS? • Required by FTA for New Starts/Small Starts Alternatives Analysis. • Required by FHWA and EPA for Air Quality Conformity Analysis. • Required for transportation policies that have temporal sensitivity, e.g.: • Variable Tolling, • Managed Lanes, • Congestion Pricing, • Travel Demand Management • It is good modeling practice. Source: FTA Workshop on Travel Forecasting for New Starts, March 2009
How To Incorporate TOD Modeling • Fixed TOD factors (The common practice). • Derived from local observed travel patterns. • Relatively easy to implement. • Assumes that travel patterns will remain the same in the future. • Not sensitive to transportation LOS changes.
How To Incorporate TOD Modeling • Econometric TOD model • Sensitive to changes in transportation LOS • Can be used to model “peak spreading” • Limited only by model structure and data in the model • Requires somewhat more work to estimate and calibrate than fixed TOD factors
Approach: Proof of COncept • Acquire test model and review model structure • Acquire and prepare base year travel data • Develop fixed TOD factors for model region based on observed local travel • Restructure the test model • Implement fixed TOD factors in the base year model • Implement and test TOD peak spreading model • Model calibration and validation
The Test Model • Model Region: Capital Region (CRTPA) • Base Year: 2007 • Model Base Year Inputs: SE data, and all base year inputs provided by CRTPA.
Base Year Travel Data • Not essential for proof of concept • Hourly traffic counts (Florida DOT and City of Tallahassee, Other local jurisdictions) • Transit on-board survey (City of Tallahassee) • Household travel survey data (Florida DOT) • Census/ACS Journey to Work data
Review of TEST Model • FSUTMS four-step model • Daily highway assignment, Peak and Off-peak transit assignment • Five internal trip purposes generated and distributed (HBW, HBSH, HBSR, HBO, NHB) • Three trip purposes modeled in mode choice (HBW, HBO, NHB) • No feedback of congested impedance • No car-sufficiency data • Autocon(?)
Develop Local TOD Factors • Not essential for proof of concept • Develop fixed TOD factors for model area • Use 2009 NHTS data • Provide methodology for other planning jurisdictions to develop their TOD factors.
Existing Structure of the Test Model Any Model Scenario Year Trip Generation (Daily) Trip Distribution(Daily) Mode Choice(Daily) Trip Assignment: (Highway – Daily; Transit – PK/OP)
Restructure The Test Model Base Year Future Year Note: For each global iteration the Future Year model is run for All TOD periods before the TOD peak spreading sub-model is applied. Trip Generation Trip Generation Factor P’s & A’s by Fixed TOD Factors (9 TOD P/A Tables) Factor P’s & A’s by Fixed TOD Factors (9 TOD P/A Tables) Trip Distribution by TOD Trip Distribution by TOD Mode Choice by TOD Mode Choice by TOD Highway Assignment by TOD Assignment by TOD Skim Base Year LOS by TOD Skim Future Year LOS by TOD Transit Assignment (PK/OP) Apply TOD Peak Spreading) Sub-Model by Trip Purpose No Yes Convergence? END Transit Assignment
Restructure The Test Model • Nine TOD periods: • Very Early AM (3:00 to 5:59) • Early AM (6:00 to 6:59) • AM Peak (7:00 - 8.59) • Late AM (9:00 to 9:59) • Midday (10:00 AM -1:59 PM) • Early PM (2:00 to 2:59) • PM Peak (3:00 PM – 5:59) • Late PM (6:00 – 6:59) • Night (7:00 PM to 2:59AM)
Restructure The Test Model • Internal Trip Purpose by Direction: • Home-based Work • HBW to Work • HBW to Home • Home-based Shopping • HBSH to Shop • HBSH to Home • Home-based Social/Recreation • HBSR to SocRec • HBSR to Home • Home-based Other • HBO to Other • HBO to Home
TOD Peak Spreading Sub-Model • Incremental logit model • Driven by difference in travel impedance for modeled year versus base year • Apply in future year where significant congestion growth is expected • Requires all TOD periods to be modeled explicitly. • Model applied for each trip purpose independently • Creates adjusted trip tables after highway assignment for iterative feedback through trip distribution, mode choice and assignment
Test Convergence Calculate Difference in LOS for TOD Period (Future Year compared to Base Year: Calculate Trip Tables for next feedback iteration: Calculate absolute difference (cell by cell) in each trip table (current compared to previous) for all TOD and all Purposes and compare result to convergence criterion, δ. Feedback to Trip Distribution No All Converge? Yes END
Additional Thoughts… • Run time, in general • Feedback of impedance in Base Year • Averaging of adjusted trip tables • TOD factors for Truck & Taxi, IE and EE trip purposes
Questions? Thank You!