GATE (CE) 2022:Highway Engineering:18 (App update required to attempt this test)

Calculate the total cycle time by Webster’s approach with the following data in a two phase traffic:

All red time required for pedestrian crossing = 12 sec

Amber time = 3 sec

y_a and y_b for cross roads A and B are 0.35 and 0.25

Assertion(A): Webster’s method of traffic signal design is an analytical approach.

Reason(R): The goal is to minimize the total delay to all the vehicles at the approach roads of the intersection.

A pre-timed four phase signal has critical lane flow rate for the first three phases as 200, 187 and 210 veh/hr with saturation flow rate of 1800 veh/hr/lane for all phases. The lost time is given as 4 seconds for each phase. If the cycle length is 60 seconds, the effective green time (in seconds) of the fourth phase is _________

An isolated three–phase traffic signal is designed by Webster’s method. The critical flow ratios fort three phases are 0.20, 0.30, and 0.25 respectively, and lost time per phase is 4 seconds. The optimum cycle length (in second) is ________________

Find out the cycle length (in seconds) for a 2-phase intersection as per the Webster’s method. The flow on road A and B are 275 PCU and 315 PCU respectively. The saturation flow on each road is 765 PCU per hour. Assume the time lost to be 15 seconds.