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Congestion and Time-Of-Day Forecast Outcomes of an Activity-Based Model . Congestion and Time-Of-Day Forecast Outcomes of an Activity-Based Model. Erik Sabina – Regional Modeling Manager Suzanne Childress – Senior Modeler Transportation Research Board Planning Applications Conference
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Congestion and Time-Of-Day Forecast Outcomes of an Activity-Based Model
Congestion and Time-Of-Day Forecast Outcomes of an Activity-Based Model Erik Sabina – Regional Modeling Manager Suzanne Childress – Senior Modeler Transportation Research Board Planning Applications Conference Reno, Nevada, May 10th, 2011
A Bit About Denver • 2010 • Population 2.9m • Employment 1.6m • 2035 • Population 4.5m • Employment 2.6m • Planning Goals • Urban Centers • Urban Growth Boundary • New regional light rail • TODs
The answer: probably two threads • Expected time of day effects of the activity-based model. • Interaction effects between disaggregate demand-side model and aggregate supply side (static equilibrium)
The new FOCUS Model Population Synthesis Work-based Sub-tour Generation Workplace Location Tour Destination School Location Tour Mode Auto Availability Tour Time of Day Daily Activity Pattern Intermediate Stop Generation Exact Number of Tours Intermediate Stop Location Work Tour Destination Type Trip Mode Intermediate Stop Departure Time
The new FOCUS Model Population Synthesis Work-based Sub-tour Generation worker? Workplace Location Tour Destination School Location Tour Mode Auto Availability Tour Time of Day Daily Activity Pattern Intermediate Stop Generation Exact Number of Tours Intermediate Stop Location Work Tour Destination Type Trip Mode Intermediate Stop Departure Time
The new FOCUS Model Population Synthesis Work-based Sub-tour Generation worker? Workplace Location Tour Destination School Location Tour Mode Auto Availability Tour Time of Day Daily Activity Pattern Intermediate Stop Generation Exact Number of Tours Intermediate Stop Location Work Tour Destination Type Trip Mode Intermediate Stop Departure Time
Key variables: accessibility Population Synthesis Work-based Sub-tour Generation Workplace Location Tour Destination School Location Tour Mode Auto Availability Tour Time of Day Daily Activity Pattern Intermediate Stop Generation Exact Number of Tours Intermediate Stop Location Work Tour Destination Type Trip Mode Intermediate Stop Departure Time
Key variables: age Population Synthesis Work-based Sub-tour Generation Workplace Location Tour Destination School Location Tour Mode Auto Availability Tour Time of Day Daily Activity Pattern Intermediate Stop Generation Exact Number of Tours Intermediate Stop Location Work Tour Destination Type Trip Mode Intermediate Stop Departure Time
Our Trip-Based Model i. Network Processing ii. Area Type 1. Trip Generation i. Highway/Transit Skims 2. Trip Distribution 3. Mode Choice i. Parking Cost ii. Time-of-Day 4. Highway/Transit Assignment
Calibration Outcome: trip time of day Trip time-of-day
Calibration Outcome: trip time of day versus VHT Trip time-of-day VHT
Possible Remedies • Interfere with the calibration outcomes of the time-of-day choice models – REALLY BAD IDEA! • Adjust “WriteTripsToTransCAD” module • Module that writes from database into TransCAD matrices for assignment • Outbound half-tour trip times are arrival times – bias backward in time. • Return-bound half-tour trip times are departure times – bias forward in time. • Key point – distribution INSIDE each hour. • Proper remedy – DTA?
Conclusions • Interaction issues between static assignment and ABMs can significantly affect congestion outcomes. • ABMs do show “peak spreading” in forecast years (at this point, not appearing to be huge.) • Demographic and accessibility variables appear key. • Calculate arc elasticities via scenario runs to better evaluate sensitivities. • Validation will be a challenge in any case.
Contact Information • Suzanne Childress – schildress@drcog.org • Erik Sabina – esabina@drcog.org • 303-455-1000
Influence of components Population Synthesis Work-based Sub-tour Generation Workplace Location Tour Destination School Location Tour Mode Auto Availability Tour Time of Day Daily Activity Pattern Intermediate Stop Generation Exact Number of Tours Intermediate Stop Location Work Tour Destination Type Trip Mode Intermediate Stop Departure Time
Calibration Outcome: trip time of day versus VHT Trip time-of-day