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Innovative ToolsOctober 27, 2011
Chi Mai
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Presentation Overview
• VISSIM Corridors
• VISSIM Protocol
• Hours of Congestion
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VISSIM Corridors
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Why VISSIM as an Analysis Tool in Region 1?
• Major transportation corridors are operating at and over capacity
• Need a tool to model queue spillbacks and freeway weaving operations
• Complex multi-modal transportation system - ramp meter operations, transit (streetcars and buses), and pedestrians
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VISSIM Operational Corridors
• OR217 (I-5 to US26)– Applied to the OR217 Corridor Study
• I-5 (Wilsonville Rd Intchge to I-405)– Being applied to I-5 Bottleneck Study
• I-205 (I-5 Wilsonville to I-84)– Being applied to I-205 Bottleneck Study
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Time Period Modeled
• 4-hour AM Model– 6:00 AM to 10:00 AM
• 5-hour PM Model– 2:00 PM to 7:00 PM
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Data Collected
• Traffic Volume Data
• Travel Time Data
• Spot Speed Data
• Queuing Data
• Control Data
• Geometric Data
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VISSIM Protocol
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History with VISSIM• June 2005 - Purchased VISUM and
VISSIM package license • October 2007 – developed “VISSIM
Protocol for Simulation on Freeways” (Region 1 – Portland Metro)
• June 2011 - completed update to “Protocol for VISSIM Simulation” for freeways and arterials and for statewide use
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Updated Protocol Requires• Developing a clear problem statement and
objective for VISSIM model
• Process of developing VISSIM model– Check-in points– Review at every critical step– Consultant/Agency reviewer knows exactly
what is expected at each deliverable – Checklist for reviewer
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Improved Process• Consultants can better prepare work
scope, timeline and budget for project
• Agency can receive the product we scoped for
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Hours of Congestion
Developing an Empirical Tool for Estimating Duration of Congestion
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How Can Transportation Decisions Be Made When Standards Are Not Meaningful?
• What does it mean when peak hour volume to capacity (v/c) ratios far exceed 1.0?
• What is the difference between a peak hour v/c ratio of 1.3 and 1.6? How much worse is congestion on the facility?
• A measure of congestion “duration” is needed to evaluate networks in this condition
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Congestion “Spreading” Analysis Can Provide Decision Makers Insight Into the Reality of Congestion
• If financial constraints, land use forecasts, and policies on facility sizing = severe peak hour failure, how many hours of the day are congested?
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Current Regional Travel Demand Models Are Not Built To Predict Congestion “Spreading”
• Trips are developed for daily trip purposes• Peak period trip tables are built with fixed time-of-day
factors– Portland Metro Model Time Periods
• AM Peak (7AM - 9AM, 2 hours)• Midday Peak (Noon - 1PM, 1 hour)• PM Peak (4PM - 6PM, 2 hours)
• Network congestion affects trip distribution, mode choice, and assignment, but excess demand is not forced into shoulder periods
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Forecasting the Duration of Congestion Improves Improves Regional Transportation DiscussionsRegional Transportation Discussions
• Hours of Congestion provides a duration measure for congested urban networks
• Hours of Congestion adds a new dimension to understanding key regional bottlenecks
• Hours of Congestion helps identify and assess locations for operations improvements
• Hours of Congestion provides a comparison to known nationwide severely congested corridors
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Hours of Congestion (HOC) Approach: Data Mining to Build a Travel Demand Model Post-
Processing Tool
• Data Mining Sources– PORTAL Data (Database of Freeway Loop Detectors) – 4 yrs of data
– ATR Data (Database of Permanent Count Recorders) – 4 yrs of data
– Roadway Tube Counts (Sample Daily Hourly Profiles) – 100+ data points
– Bus GPS Records (Database of Corridor Travel Speed) – 6 weeks of data
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Introducing Hours of Congestion Into the Transportation Planning Process
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Hours of Congestion provides a duration measure for congested urban networks
OR 43 (Macadam Avenue) northbound at Gaines Street, 2035
I-5 northbound ramp to Marquam Bridge, 2035
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Hours of Congestion adds a new dimension to understanding key regional bottlenecks
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Hours of Congestion helps identify and assess locations for operations improvements
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Hours of Congestion provides a comparison to known nationwide severely congested corridors
Source 2009 Data: INRIX National Traffic Scorecard 2009 Annual Report
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Questions?
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