INTERSECTION MODEL COMPONENTS

1. INTERSECTION MODEL COMPONENTS TTE 6815 K. Courage

2. TOPICS • Queue accumulation polygon • Uniform delay, stops & queue • Effects of random arrivals • Effects of oversaturation • Effects of coordination • Unsignalized control

3. QUEUE ACCUMULATION POLYGON (QAP) ASSUMPTIONS • Cyclical repetition • Uniform arrivals over the whole cycle

4. QUEUE ACCUMULATION POLYGON (QAP) Maximum queue accumulation

5. DELAY • Uniform delay • Incremental delay • Deterministic queue delay

7. UNIFORM DELAY (sec/veh) • C = Cycle length • 8 = Green / cycle • X = Degree of Saturation

9. HCM 94/97

10. NCHRP 3-48

11. STOPS • Arrival on red • Arrival on green before queue has cleared

12. Stopped Not stopped

13. UNIFORM STOPS • 8 = Green / cycle • X = Degree of Saturation

14. EFFECT OF RANDOM ARRIVALS • Different QAP each cycle • Probability of overflow

16. QUEUE SIZE • Maximum queue accumulation • Maximum queue reach

17. Max Reach Max Accumulation Front of queue Back of queue

18. UNIFORM QUEUE REACH • q = arrival rate per sec = Volume (vph) / 3600

19. What Happens When The Demand Exceeds The Capacity?

20. Tp Time

21. UNDERSATURATION Tp Time ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^

22. Deterministic Queue Delay OVERSATURATION DQD Tp ^^^^^^^^^^^^^^^^^^^^^^^^^^^ ^^^^^^^^^^^^^^^^^^^ ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^

23. OVERSATURATED DELAY DEFINITIONS • Delay per vehicle within the analysis period • Delay to each vehicle arriving during the analysis period

24. DEFINITION # 1

25. # of vehicles in queue DEFINITION #2

26. DEFINITION #2 Delay to nth vehicle

27. DQD Uniform DELAY MODEL 1.0 DELAY X

28. GENERALIZED INCREMENTAL DELAY EQUATION

29. EFFECT OF SIGNAL COORDINATION • Uniform: QAP arrivals • Incremental: Reduced randomization

30. QUANTIFICATION OF PROGRESSION QUALITY • Arrival type • Time-space diagram • Flow profile • Implicit treatment by simulation

31. MODELING OF COORDINATED SIGNALS • Performance • Platoon dispersion • Optimization criteria and procedures