Task 3: The Intersection design a. Describe the various principles involved in the design of at-grade intersections and the different types of at-grade intersections. Also, give an example of an appropriate location for the use of each type. b. Design a suitable signal phasing system and phase lengths for the intersection using the Webster method. Show a detailed layout of the phasing system and the intersection geometry used for the geometric and traffic characteristics shown in table 6 below. And the saturation flow of the intersection is shown in table 7 Discuss the effect of increasing saturation flow rates by 10% higher on the cycle length? Table 6:The geometric and traffic characteristics of the intersection Approach (Width) North (56m) South (56 m) East (68m) West
Task 3: The Intersection design
a. Describe the various principles involved in the design of at-grade intersections and the different types of at-grade intersections. Also, give an example of an appropriate location for the use of each type.
b. Design a suitable signal phasing system and phase lengths for the intersection using the Webster method. Show a detailed layout of the phasing system and the intersection geometry used for the geometric and traffic characteristics shown in table 6 below. And the saturation flow of the intersection is shown in table 7 Discuss the effect of increasing saturation flow rates by 10% higher on the cycle length?
Table 6:The geometric and traffic characteristics of the intersection
| Approach (Width) | North (56m) | South (56 m) | East (68m) | West (68m) |
| Peak hour approach volumes | ||||
| Left turn | 133 | 73 | 168 | 134 |
| Through movement | 420 | 373 | 563 | 516 |
| Right turn | 140 | 135 | 169 | 178 |
| Conflicting pedestrian volumes | 900 | 1200 | 1200 | 900 |
| PHF | 0.95 | 0.95 | 0.95 | 0.95 |
Assume the following saturation flows:
Table 7: The saturation flow of the intersection
| Through lanes Veh/ln/h | Through and right lanes Veh/ln/h | Left lanes Veh/ln/h | Left and through lanes Veh/ln/h | Left, though, and right lanes Veh/ln/h | saturation flow rates % |
| 1600 | 1400 | 1000 | 1200 | 1100 | 10 |
c. A two-phase signal system is installed at an un-signalized + intersection with channelized left-turn lanes and shared through and right-turn lanes. Using a suitable diagram, determine the possible conflict points. Indicate the phasing system used.
Trending now
This is a popular solution!
Step by step
Solved in 2 steps
