14. Signal Design Flashcards
1
Q
What is the saturation flow rate?
A
The maximum hourly volume thru an intersection from a given lane if signal was constant green for an hour.
s (veh/hr) = 3600/saturation headway (sec/veh)
2
Q
What is (intersection) capacity?
A
The hourly volume that be accommodated for an intersection approach given that the approach will receive less that 100% green time.
c = N x s x (g/C)
3
Q
What is lost time?
A
The combination of the start-up and clearance lost times. Includes: start-up (2.0s) , yellow change interval (2.0s), red clearance interval, and effective green extension (2.0s, subtracted from lost clearnace time)
4
Q
What is a flow ration for a phase
A
Volume/saturation flow rate
