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DKS Associates. A Hybrid Model for CSMP. Outline. Corridor System Management Plan (CSMP) Travel Demand vs. Simulation Models Micro vs. Meso Simulation Models US-101 Corridor Modeling Methodology and Techniques. A Hybrid Model for CSMP. CSMP – A New Approach.
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A Hybrid Model for CSMP Outline • Corridor System Management Plan (CSMP) • Travel Demand vs. Simulation Models • Micro vs. Meso Simulation Models • US-101 Corridor • Modeling Methodology and Techniques
A Hybrid Model for CSMP CSMP – A New Approach A new approach of taking planning through operations Using simulation as a planning tool Taking a new look at existing conditions Creating a living document that will extend the life of the corridor plan
A Hybrid Model for CSMP Corridor System Management Plans (CSMP) Evaluate System Management Approach Summarize Corridor Conditions Ensure Adequate Detection Develop Preliminary Performance Comprehensive Corridor Performance Assessment Stakeholder Involvement – Consensus Building Forecast Future Travel Identify Causality and Degradation Develop CSMP Test Scenarios Acceptance by MPO and Caltrans District – 5, District – 7 and HQ
A Hybrid Model for CSMP Key Challenges • Simulating a very large corridor (50*4 miles2) • Dealing with multiple stakeholders • Integrating information from three existing travel demand models • Bridging the gap between travel demand models and simulation models • Developing future-year simulation models • Assessing operational strategies • Making the processes livable in supporting future CSMPs.
A Hybrid Model for CSMP Santa Barbara County Ventura County Goleta Santa Barbara Carpinteria US-101 at the CMIA Project Area Ventura Oxnard
A Hybrid Model for CSMP Reality Travel Demand Model Simulation Model Travel Demand vs. Simulation Models
A Hybrid Model for CSMP (Static) Travel Demand Model
A Hybrid Model for CSMP (Dynamic) Simulation Model
A Hybrid Model for CSMP MICROscopic Simulation • Simulates the movement of individual vehicles based on car-following and lane-changing logics. • Has the highest detailed assessment (but the size of network is limited due to its computationally expensive and sensitive to gridlocks).
A Hybrid Model for CSMP MESOscopic Simulation • Relatively less detailed assessment but can cover a larger network. • Unit of traffic flow is the individual vehicle; however, their movements are governed by the basis of aggregate speed/volume relationship instead of car-following and lane-changing theories.
A Hybrid Model for CSMP Hybrid Simulation • Take advantages of microsimulation to model roadway segments of interest and yield relatively less detailed in modeling side streets. • Both parts are simulated simultaneously within the same run--no discrepancy between the two parts.
A Hybrid Model for CSMP US-101 Outer Inner Core US-101 Hybrid Simulation Model in Santa Barbara Core Inner Outer
A Hybrid Model for CSMP US-101 Hybrid Simulation Model in Ventura
A Hybrid Model for CSMP Data Collection • 247 intersection counts • 24 mainline manual counts • All on/off ramp counts for the all freeways (50*4 miles2) • 30 arterial loop counts • Tach runs for 2 days (8 probes, 15-minute headway) • Speed detectors, camcorders, etc.
A Hybrid Model for CSMP Base-year Modeling Methodology
A Hybrid Model for CSMP Base-year Modeling Methodology (1)
A Hybrid Model for CSMP Base-year Modeling Methodology (2)
A Hybrid Model for CSMP Future-year Modeling Methodology
A Hybrid Model for CSMP Future-year Modeling Methodology (1)
A Hybrid Model for CSMP Future-year Modeling Methodology (2)
A Hybrid Model for CSMP Modeling Arterials Roadways in Reality > Travel Demand Model > Simulation Model • Reality: • Too many intersections • Traffic counts are unbalanced • So, what’s best for simulation world? Real Network (with Intersection Counts)
A Hybrid Model for CSMP Modeling Arterials (2) TDM Link Sim Zone SI DZ Sim Zone Simulation Link DI DZ Sim Zone DZ DZ DI DI SI DZ DZ TDM = Travel Demand Model SI = Study Intersection DI = Dummy Intersection Sim Zone = Simulation Zone DZ = Dummy Zone DZ DI DZ Subarea Network
A Hybrid Model for CSMP Modeling Arterials (3) Need only one “Dummy Intersection” between two “Study Intersections” Sim Zone Combine O-Ds to remove unnecessary Dummy Zones SI DZ Sim Zone Simulation Link DI Sim Zone DZ SI SI = Study Intersection DI = Dummy Intersection Sim Zone = Simulation Zone DZ = Dummy Zone DZ DI DZ Interface Network
A Hybrid Model for CSMP Travel Demand Model vs. Interface Model
A Hybrid Model for CSMP Travel Demand Model vs. Interface Model (2) Combined Demands
A Hybrid Model for CSMP Dummy Intersection Interface Model Study Intersection A zone at each boundary link (one-to-one mapping)
A Hybrid Model for CSMP Simulation Model
A Hybrid Model for CSMP Path-based Routing • Allows more control to vehicle routing. Path Table Trip Data Table Path ID { Sequence of Link IDs } 809{ 1031 1032 1033 1034 1035 31209 1037 1038 1039 1040 1041 1042 1043 1134 1135 1136 1137 1138 1165 1139 36582 1166 1140 1141 28840 28838 28744 36591 28851 28941 31381 }
A Hybrid Model for CSMP Guidance • There is a big gap between the travel demand world and the simulation world. • We hope that our approach can tighten this gap. • There is a need for a dynamic ODME to help calibration. • We believe that the path-based routing is the right trend for traffic simulation.
A Hybrid Model for CSMP Guidance (2) • Base Case • Dynamic User Equilibrium • Short-term Impacts • Fixed paths (from Base Case) • Long-term Impacts • New Dynamic User Equilibrium
A Hybrid Model for CSMP Conclusions • Hybrid simulation is a new tool to model corridors. • The proposed approach is quite a unique technique to integrate travel demand models with simulation models. • Understanding traffic assignment is crucial for corridor studies; we need a good user-manual.
Thank You scp@dksassociates.com