Question

1. On one approach of an intersection with fixed time traffic signal, vehicles arrival rate is 600 vehicles per hour. The effective green time for this approach is 30 seconds, the saturation flow of this approach is 1800 vehicles per hour and the cycle time of the intersection is 80 seconds.

a. Evaluate the performance of the signal design i.e. will all vehicles clear during the green time?

b. Recommend the changes to the green time for this approach to achieve an optimum signal design i.e. If there is surplus green time, then state its value.

c. Due to a traffic incident, the original saturation flow is reduced by 20%. Will there be any delay under the new situation based on the original design? How many vehicles will experience the delay?

d. Under a new strategic transport plan to divert some vehicles to other areas, the saturation flow has been reduced to 1300 vehicles per hour by reconfiguring the layout of the intersection. Under this condition how may vehicles will be delayed in each cycle?

Answer 1