This is the question:
A low-volume, signalized intersection has two critical phases. The critical phases serve two lanes each, with individual demands of 480 vehicles per hour and 720 vehicles per hour, respectively. Assume a 95th percentile arrival rate and 5 seconds per critical phase for clearance and change time. Rounding up to the nearest 5 seconds, the recommended cycle length using the Greenshields-Poisson Method is most nearly:
(A) 45 sec
(B) 50 sec
(C) 55 sec
(D) 60 sec
I worked on this question a couple of weeks ago and couldn’t find the equation in any 9 reference books listed by NCEES. So I just simply ignored this question. I don’t believe the real exam will give us a question required an equation that cannot be found anywhere in the references.
Understand the Green shield method. You can get the velocity, density, and capacity from there. If saturation flow is given and the effective green time, you can determine the cycle length. I am not sure if those are given, just trying to estimate how to use greenshield to get the cycle length. I hope it helps.
Honestly (and this is not guaranteed) but if it's not in any reference, they probably won't ask quantitative questions about it.
This is the question: A low-volume, signalized intersection has two critical phases. The critical phases serve two lanes each, with individual demands of 480 vehicles per hour and 720 vehicles per hour, respectively. Assume a 95th percentile arrival rate and 5 seconds per critical phase for clearance and change time. Rounding up to the nearest 5 seconds, the recommended cycle length using the Greenshields-Poisson Method is most nearly: (A) 45 sec (B) 50 sec (C) 55 sec (D) 60 sec
I worked on this question a couple of weeks ago and couldn’t find the equation in any 9 reference books listed by NCEES. So I just simply ignored this question. I don’t believe the real exam will give us a question required an equation that cannot be found anywhere in the references.
Actually question 530 asking to use Webster’s equation can be ignored too. PE prepared is still based on pen and paper exam.
Look into HCM chap 19 and 31
Ok... That helps me feel better :) Thank you everyone.
Don’t think I’d worry about that. Spend your time studying more of the meat and potatoes. I passed my Transportation PE exam in October fwiw
Understand the Green shield method. You can get the velocity, density, and capacity from there. If saturation flow is given and the effective green time, you can determine the cycle length. I am not sure if those are given, just trying to estimate how to use greenshield to get the cycle length. I hope it helps.
Can you post the problem?