13 Fundamentals of Signal Timing and Design: Pretimed Signal (Traffic Engineering هندسة المرور & Prof. Saad AlGadhi)

1. CE 436 Traffic Engineering
Topic 13: Fundamentals of Signal
Timing and Design:
Pretimed Singnals (Ch. 21)
Prof. Saad AlGadhi
CE 436 –Traffic Engineering
King Saud University
email: salgadhi@ksu.edu.sa

2. Signal Timing Procedure
(Steps)
1. Develop “Phasing” plan
2. Determine Vehicular signal needs:
a. Y & AR for each phase
b. Sum of critical-lane volumes (Vc)
c. Lost time per phase and cycle (tL & L)
d. Cycle Length (C)
e. Green split
3. Check for Pedestrian crossing needs

4. there

5. Figure 21.2 Selected Signal Phase Arrows Illustrated

7. Figure 21.3 Illustration of a Two-Phase Signal

11. 200 veh/h
Cross-product Rule

12. Step 2.a

17. Step 2.b

20. Step 2.b

21. Sum of Critical v/s (Vc)
Where
Vc = sum of flow ratios for critical lane groups
(V/S)i = flow ratio for critical lane group I, and
n= number of critical lane groups
𝑉𝑐 = ෍
1
𝑛
(
𝑉
𝑆
)𝑖

22. Step 2.c: Determine Lost Time

23. Step 2.d: Calculate Cycle Length

24. Step 2.e: Splitting the Green

25. Step 3:

26. HCM Pedestrian Min. Green

27.  Example 21-1 (pp. 511-514)
 Example 21-4 (pp. 519-521)
Read Sample Signal Timing
Applications

28. H.W. # 10-Part 1
Ch. 21(p. 522)
1. 21-1
2. 21-2
3. 21-3