Murli K. Adury Youssef Dehghani Cathy Strombom Parsons Brinckerhoff Quade & Douglas, Inc.

1. A PERSPECTIVE ON APPLICATION OF A PAIR OF PLANNING AND MICRO SIMULATION MODELS: EXPERIENCE FROM I-405 CORRIDOR STUDY PROGRAM Murli K. Adury Youssef Dehghani Cathy Strombom Parsons Brinckerhoff Quade & Douglas, Inc. Seattle, WA, USA

2. Project Context • I-405 Corridor Program: • I-405 was built in 70s to alleviate congestion along I-5 • Experiencing unexpectedly high rate of growth from high tech sector (e.g., Microsoft) within I-405 corridor – resulting in high levels of congestion • Undertaking comprehensive alternatives analysis

3. Project Area Map

4. Why Micro Simulation? • Be able to evaluate realty checks on capacity enhancement elements of the preferred alternative – balancing capacity needs on arterials vs. I-405 thru better diversion mechanism • Be able to refine and/or modifycapacity enhancement elements of the preferred alternative • Be able to highlight potential deficiencies – e.g., lid concept thru downtown Bellevue

5. Why Integration? • WSDOT undertook a rigorous evaluation of the existing micro simulation software programs • Integration most suited because of its capabilities for: • Micro simulation analysis at corridor level • Equilibrium route diversion analysis • State-of-the-artmethodology for traffic simulation analysis • Being able to interface with the existing regional planning model databases

6. Model Development Process • Network preparation/calibration • Data collection • Details of network geometry • Signal timings • Traffic counts • Trip table development • Model validation analysis • Model application

7. Network Development • Included only: • I-405 & major parallel arterials (3000 links) • Major intersections (100 signalized intersections) • Initially used default parameters & refined further during validation process • Most difficult tasks: • Developing a network to fit INTEGRATION limits • Data input for microsimulation – lane geometry, signal data, turn pockets, physical attributes of roadway system

8. Trip Table Development • Regional model produced PM peak (hour) vehicle trip tables for HOVs and Non-HOVs • Post regional modeling procedure: • Direction peak-hour base year counts were seeded on designated links on I-405 and arterials • Matrix adjustment macro DEMADJ.MAC developed Heinz Spiess was used to update original matrix • Resulting O-D matrix was imported into the Integration model environment

9. Model Validation Analysis • Initial analysis indicated that study area network needed to be streamlined: • Secondary arterials were removed • Secondary signalized intersections were also removed • Hourly counts exhibited wide variations across weekdays and months: • Overall average and max/min limits were established • Attempts were made to “optimize” signal timing coordination

10. Model Validation Analysis- Continued - • Prepared summary system-wide measure: • Peak-hour demand input as % of total demand • % vehicles reached destinations • VMTs/VHTs • Total delays & stop delays • Prepared link-level summaries: • Total flow • Travel time • Queue length

11. Model Validation Analysis- Continued -

12. Model Validation Analysis- Continued - • Comparative analysis of queue build-up against recurring bottleneck areas posted on the WSDOT website • Performed additional network refinement accordingly • Accomplished reasonable base year validation results

13. Model Validation Analysis- Continued -

14. Model Application • In I-405 EMME/2 Model • Developed 2020 network for the preferred alternative • Prepared 2020 Travel Forecasts • Developed 2020 peak-hour trip table • Prepared base year to 2020 zone-to-zone growth rates • Applied implied zone-to-zone growth rate to the base year adjusted peak-hour trip table

15. Model Application- Continued - • Provided insights into the alternatives analysis process • Highlighted initially proposed improvement plan/conceptual design deficiencies within the project corridor • Identified potential bottleneck areas • Integration modeling achieved its purpose

16. Lessons Learned • Allow adequate time to: • Define objectives for why needing to do micro simulation and for what purpose • Identify appropriate software program and its limits accordingly • Identify study area carefully for: • Boundaries • Network details (no. of links & intersections)

17. Lessons Learned - Continued • Assess potential interface with other tools (e.g., regional model databases, network editing, etc.) • Trip matrices need to go through an adjustment process reflecting actual counts • Assess data needs carefully • Micro simulation model is data hungry & time consuming