Question

Part (a) ___________is defined as the maximum number of vehicles that can pass through a lane when departing an intersection over the course of an hour if allocated a constant green

Part (b) ___________ is one complete sequence (for all approaches) of signal indications (greens, yellows, reds).

Answer 1

Cycle time is the time taken by a signal to complete one full cycle of iterations. i.e. one complete rotation through all signal indications. It is denoted by C. The way in which the vehicles depart from an intersection when the green signal is initiated will be discussed now. Figure 1 illustrates a group of N vehicles at a signalized intersection, waiting for the green signal.

As the signal is initiated, the time interval between two vehicles, referred as headway, crossing the curb line is noted. The first headway is the time interval between the initiation of the green signal and the instant vehicle crossing the curb line. The second headway is the time interval between the first and the second vehicle crossing the curb line.

Clearance interval is also called all red and is provided after each yellow interval indicating a period during which all signal faces show red and is used for clearing off the vehicles in the intersection