Consider the intersection on the next page. As shown in the figure, a 4-phase signal
design is being planned for the intersection. Local state traffic regulations require that the
"equivalent critical thru-volume" discharge at the intersection cannot exceed 75% of the
maximum possible "equivalent thru-volume" discharge. With this in mind, compute the
following:
1a) The minimum cycle length required
1b) The green and red time lengths for each phase.
Also, draw a signal timing plan based on your results from 1b.
You may assume the following:
lost time/phase = 4 sec.
amber time = 5 sec. for all phases
Ideal saturation headway = 2.1 sec.
1 left turn/right turn = 1.4 equivalent thru-movement (1.4T)

 

  

1. Consider the intersection on the next page. As shown in the figure, a 4-phase signal design is being planned for the intersection. Local state traffic regulations require that the "equivalent critical thru-volume" discharge at the intersection cannot exceed 75% of the maximum possible "equivalent thru-volume" discharge. With this in mind, compute the following: la) The minimum cycle length required 1b) The green and red time lengths for each phase. Also, draw a signal timing plan based on your results from 1b. You may assume the following: lost time/phase amber time Ideal saturation headway 1 left turn/right turn = 4 sec. = 5 sec. for all phases = 2.1 sec. = 1.4 equivalent thru-movement (1.4T)