Basic HTML Version
Chapter 7: Timing Processes for the Intersection
225
In Chapter 6, you studied the operation of one intersection approach and determined the value of the
vehicle extension time that would extend the green for as long as a queue existed, but not longer. The
focus was on the traffic flow and signal timing on one approach only, with no consideration of the effect
of this value on the other intersection approaches. In this chapter, now that you have established a basic
understanding of the timing processes for one approach of an intersection, we will consider how the timing
parameters on one approach affect the operation on the other approaches and the intersection overall.
When you have completed the activities in this chapter, you will be able to
•
Describe the function of the maximum green time
•
Describe the effect of the maximum green time on the cycle length and delay
•
Describe the maximum green time setting and timer process
•
Determine the optimal maximum green time (based on the optimal cycle length) at a signalized
intersection
•
Determining the effect of the minor street vehicle extension setting on the efficiency of major street
and intersection operations
•
Describe the advantages and disadvantages of increasing maximum green time on intersection
operations
•
Set the maximum green time for both approaches of an intersection, balancing the performance of both
the minor street and the major street
•
Compare the maximum green times that you developed in your design with those used in practice
This chapter begins with a
Reading
(Activity #39) on the relationship between the maximum green time,
the cycle length, and delay. The chapter also includes four activities including an assessment of your
understanding of the effect of the maximum green time on intersection operations (Activity #40), the effect
of long vehicle extension times on one approach on the operation of the other approaches (Activity #41),
and the pros and cons of increasing the maximum green time in order to solve the problem of phase failure
(Activity #42). You will complete a design activity (Activity #43) in which you will select the maximum
green time for the design project with which you have been working. The chapter concludes with an
In
Practice
activity (Activity #44) with background on the maximum green time, both recommended values
for its setting and how this timing process works.
7
Timing Processes for the Intersection