1. TSSM BI-WEEKLY MEETING and Stakeholder Update
July 10th, 2017

2. Meeting Topics Review current schedule
Critical need chapter drafts due on November 21st
Progress checkpoints and self-assessment
July 21st (one-third checkpoint)
September 21st (two-thirds checkpoint)
Re-open comment tracking site in September
Chapter review assignments in September
Review interest level per chapter
Seek consensus on technical topics
Chapter outlines, VC&V definitions
Intermediate need topics (optional)

3. Outreach Timeline (draft)
July 10th ~1/3rd checkpoint
Traffic analysis PFS
TRB Task Force
Stakeholder webinar #3
(annotated outline review)
Start project
2016
2017
2018
2019
Interviewed 16
PFS states
TRB Mid-Year
HCQSC (Sturrock)
September 18th ~2/3rd checkpoint
Assign chapter reviews*
Traffic analysis PFS
TRB Task Force
ITE SimCap & TENC**
TRB SimSub & others**
* re-open comment tracking site
** contact Chris/David if interested

4. Interest Level per Chapter
Chapter 5: Defining the Problem
Chapter 6: Data
Chapter 7: Creating the Model
Chapter 8: VC&V
Chapter 9: Output & Visualization

5. Chapter 5 (Defining the Problem)
Scoping overview
Questions simulation can and cannot answer
Connecting simulation objectives to project purpose
Estimating effects of business/regulatory/emerging technologies
Geographic limits
Time periods and timeframes for analysis
Baseline scenario
Build alternatives
Operating conditions (e.g., cluster analysis)
Performance measures
Externalities (e.g., spillover effects, demand effects)
Verification and validation checks
Documentation

6. Chapter 6 (Data) Two candidate outlines Data type-oriented outline
Network data, traffic data, control data, IT subsystem data, operating condition data
Analysis type-oriented outline
Data needs assessment; types and sources; fusion and aggregation
Simple facility analysis, corridor analyses, city-wide needs, annual reliability context, multimodal consideration
Success stories
Other considerations
Data requirements for meso, macro, micro analyses

7. Chapter 7 (Creating the Model)
Page 1: Initialization and Equilibrium
Network Development (5 pages)
Page 2: Conventional Windows-based data entry
Page 3: Data entry over a ‘bitmap background’
Page 4: Pre-processors
Page 5: Importing detailed traffic data
Page 6: Raw data entry
Geometric Data (6 pages)
Page 1: Links
Page 2: Nodes
Page 3: Link-node versus link-link connections
Page 4: Link lengths and curvature
Page 5: Super-elevation and grade
Page 6: Lane-specific data
Traffic Data (9 pages)
Page 1: Origin-destination volumes and matrices
Page 2: Intersection turn movement volumes
Page 3: Conditional turn movements
Page 4: Lane utilization and pre-positioning
Page 5: Off-ramp exit volumes
Page 6: Multi-period volumes
Page 7: Vehicle fleet composition
Page 8: Driver characteristics
Page 9: Headway and saturation flow rate
Control Data (9 pages)
Page 1: Pre-timed traffic signal control
Page 2: Actuated traffic signal control
Page 3: Actuated traffic signal detectors
Page 4: Ramp meters
Page 5: Freeway detectors
Page 6: Sign controlled intersections
Page 7: Freeway warning signs
Page 8: Toll plazas
Page 9: Roadway pricing
Operating Condition Data (8 pages)
Pages 1-2: Demand variability
Pages 3-4: Weather
Page 5: Incidents
Page 6: Pavement quality
Page 7: Work zones
Page 8: Special events

8. Chapter 8 (Verification and Validation)
Software logic reflects system behavior (software developers)
Input data correctly describe the system (users)
At the end: logic is okay and the input data are clean.
Validation
Model predictions match observed system behavior (users)
Model parameters correctly adjusted (Calibration)
At the end: parameters are suitably tuned and model predicts observed behavior to an acceptable degree.
Static and Dynamic Conditions
Static: steady state behavior
Dynamic: transient behavior

9. Potential Problems Verification Validation
Logic (theory) is flawed (developers)
Software incorrectly implements the logic (developers)
Model is being used outside its applicable domain
Network is incorrectly specified
Controls employed are incorrect
Validation
Operating conditions are incorrectly specified
System performance is incorrectly described
Parameter values are incorrectly specified
Model produces invalid results for untested situations

10. Hierarchical Checking
Used for both verification and validation
Checks performed on
Individual elements
Subsystems
Clean datasets – inputs for which the outputs are known.
Overall system
Focus on
System dynamic trends (temporal and spatial)
Travel times (OD, route)
Queue dynamics (length, delay)
Travel rates (speeds) for individual segments
Vehicle inputs processed (entered and exited)

11. Consistency in Terminology
Verification: The process of determining that a model implementation accurately represents the developer’s conceptual description of the model and the solution to the model.
Validation: The process of determining the degree to which a model is an accurate representation of the real world from the perspective of the intended uses of the model.
Calibration: The tuning of model parameters to achieve some degree of agreement with existing validation experiments
Adapted from: Oberkampf, Trucano, and Hirsch, 2002; and Schlesinger, 1979

12. Definitions in the TAT
Verification: Process where the software developer and other researchers check the accuracy of the software implementation of traffic operations theory. Perhaps should also focus on verifying that the input data correctly describe the system being studied.
Calibration: Process where the analyst selects the model parameters that cause the model to best reproduce field-measured local traffic operations conditions. Performed using some of the field data. This is effectively part of the validation. Valid results cannot be obtained without calibration.
Validation: Process where the analyst checks the overall model-predicted traffic performance for a street/road system against field measurements of traffic performance, such as traffic volumes, travel times, average speeds, and average delays. Performed based on field data not used in the calibration process.

13. Intermediate Need Topics (optional)
Mesoscopic simulation approach
Examples of multi-scale modeling
Uncertainty analysis
Discussion of models at the discrete level
e.g., car-following, dynamic traffic assignment, cell transmission
Content of Chapter 7 (Creating the Model)
Content of Chapter 9 (Output Processing, Analysis, Presentation)

14. Questions and Answers Thank You