Case Study 5 Museum Road Educational and Training Presentation Problem 2

1. Case Study 5Museum RoadEducational and Training PresentationProblem 2

2. Problem 2 2a. Fully actuated signal - Improved T intersection - Minimum green times - Exclusive pedestrian phase 2b. Signalized analysis - Phasing options - Combining movements - Reduced cycle length 2c. Coordination effects - Arrival type - Unit extension and k-value - Delay (d1 and d2)

3. Overview of the Problem • Fully actuated signal • Lane configuration • Volumes and PHFs • Pedestrian flow rates • Pedestrian crossing data • Bicycle flow rates • Queue spacing • Queue storage • Grades • Heavy vehicles • Parking data • Bus stop data

4. Overview of the Problem (cont.) • Critical data • Traffic, geometry and signal phasing

5. Run Overview of the Problem (cont.) Initial Run • Queues: Important to look at independently • Delays: Important to look at all movements • LOS: Overall intersection not the only LOS

6. Problem 2a: fully-actuated signal • Pedestrian effects • Minimum green times • Crossing distance of 50 ft • Crosswalk width of 10 ft • Walking speed of 4 fps  Yields a minimum green of about 20 sec

7. Problem 2a: fully-actuated signal • Pedestrian effects • Exclusive pedestrian phase Will pedestrians get more time than before? What are the benefits of an exclusive pedestrian phase?

8. Run Problem 2a: fully-actuated signal • Pedestrian effects • Exclusive pedestrian phase • Pedestrians accommodated more efficiently and safely • However, the intersection performance is compromised • SB approach from LOS C to LOS E/F • Intersection from LOS D to LOS E

9. Problem 2b: signalized analysis • Signal phasing options • EB left-turn movement critical • SB right-turn movement critical • Modify phasing to improve?

10. Problem 2b: signalized analysis • Adding protection • Combining movements • Modifying cycle length • More protected time to deficient movements • Concurrent movements for efficiency • Lower cycle and still accommodate needs

11. Run Problem 2b: signalized analysis

12. Problem 2c: coordination effects • Signal control options - Fully actuated - Semi-actuated - Coordination • Analysis factors affected? • Arrival type  Progression factor • Unit extension  k-value

13. Problem 2c: coordination effects • Arrival type • 1 – Very poor progression • 2 – Unfavorable progression • 3 – Random arrivals • 4 – Favorable progression • 5 – Highly favorable progression • 6 – Exceptional progression • Progression factor – Accounts for effects of progression • Unit extension – Minimum gap between successive vehicles • k-value – Accounts for effects of actuation

14. Observations? Problem 2c: coordination effects Progression effects on delay: • Arrival type described level of progression • Progression factor applied to uniform delay (d1) term Actuation effects on delay: • Unit extension describes actuation activity • k-value applied in the incremental delay (d2) equation Progression factor is 1.0 for fully actuated intersections  But actuation is accounted for in the k-value Progressed phases are not actuated (k-value = 0.5)  But progression accounted for in the progression factor

15. Run Problem 2c: coordination effects • Comparing operations • Fully actuated (but not progressed) • Semi-actuated (with progression)

16. Run Problem 2c: coordination effects • Comparing cycle lengths • 120-second cycle • 60-second cycle