1. Traffic Simulation Model Theory and Application Basics of Traffic Simulation Course Instructors: Mark Hallenbeck, Director, UW TRAC Tony Woody, P.E., CH2M HILL Offered By: UW TRANSPEED xxxxx, 2008

2. What is Transportation Analysis? Traffic Analysis Quantifies Results for Decision Making Purposes Traffic Analysis Identifies Impacts to the Transportation System Many Type of Analysis can be conducted Long Range Planning Mid-Range Planning Operational Analysis

3. What is Transportation Modeling? “Analysis of Transportation Systems and Facilities using abstract networks that are based on mathematical and statistical functions and formulas.” Purpose: To replicate “real-life” behavior as best as possible to help make decisions on design, operational, and demand management strategies. Very Broad term – Can encompass all types of analysis Traffic Forecasting  Can be Simple or Complex Operational Analysis  Can be Simple or Complex

4. Overview of Transportation Modeling An Imperfect Science Relies on Algorithms, Judgment, Field Data, and “Human Element” Models Categorized by Scale: Macro Meso Micro Models Categorized by Purpose Optimization Tools Traffic Operational Performance (Stochastic, Deterministic) Travel Forecasting Models

5. Types of Analysis Tools Sketch Planning Tools Easy, Less Detailed Travel Demand Modeling Demand Modeling – Typically Long-Range and Broad in Scope Operational Analysis Deterministic Models (i.e. Synchro, HCM) Simulation Models (i.e. VISSIM, CORSIM)

6. Some Notes on Analysis Tools Each Tool has its purpose Each Project is different and may use all or some combination of the tools Each Tool has differences: Data Requirements Complexity & Level of Detail Required Size and Function Training/Experience Required Time/Resource Commitments Different Outputs

7. Travel Demand Models What they are: Macro Level Analysis Node-Link Applications of Travel Demand Models Long-Range Impacts on System Demand on Transportation Facilities

8. Traffic Operational Models What they are: Detailed analysis of traffic flows and vehicles Typically are Link-Node or Link-Connector structure Applications of Operational Models Quantify Facility Operations (Intersections, Freeways, Transit Systems) Focused Analysis Two Sub-Groups of Operational Models Deterministic Models (Based on Equations) Simulation Models (Based on Stochastic Processes)

9. Traffic Operational Models: Deterministic Equation and Empirical Data Based Same Inputs = Same Outputs Does not Require Multiple Runs Isolated Analysis Typically Quick to Build but Data Intensive Common Models: HCM, Synchro, Sidra

10. Traffic Operational Models: Stochastic Simulation Stochastic Based (Distributions for Inputs) System-Wide Analysis Very Data Intensive Complex Driver Behavior Characteristrics

11. What Microscopic Traffic Simulation is: Based on probability and stochastic processes A System Wide Analysis over Time and Space A model that includes Driver Behavior Characteristics A tool that models individual vehicles A tool that can have visual Representation w/3D A tool that can be integrated with other types of models Able to model complex signal control systems A model that requires more work than your average model!

12. What a Microscopic Traffic Simulation is not: Not an Optimization Tool Not an Demand Estimation Tool Not an HCM based Analysis Tool Not just an Visualization tool (not jut pretty pictures) Not a deterministic Analysis Method (Like HCM, Synchro, Sidra)

13. Signal Optimization & Assignment Models Signal Optimization Models Used to Optimize Splits, Phasing, Offsets, Cycle Lengths Typical: Transyt-7F, Synchro, PASSER, Signal 2000, HCS + Assignment Models/Methods Simulation Dynamic Assignment Travel Demand Modeling Assignment

14. Software Packages vs. Types of Models Often, Software incorporates many types of models into one A variety of applications can be incorporates into one model Oftentimes software vendors develop there own standards/algorithms Important to understand the intricacies of the software programs and their relationship to the theory. (When to use, How to use, what are they considered, etc.)

15. Popular Software Packages Software PackageDemand Model Traffic Simulation Freeway Deterministi c Arterial Deterministi c Signal Optimization Traffic Assignment Trafficware: Synchro/SimTraffic XXX Inro: EMME/3 XX TEAPAC: Signal 2000 etc XX FHWA: HCM/Transyt/CORSI M XXXX PTV Vision: VISSIM/VISUM XXxX Caliper Corporation: TransCAD/TransMode ler XXX