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Chapter 7: Timing Processes for the Intersection
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The purpose of this activity is to set the maximum green time for your intersection such that the delay is
optimized for all approaches and for the intersection as a whole.
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Set the maximum green time for both approaches of an intersection, balancing the performance of both
the minor street and the major street
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VISSIM file from Activity #37
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Prepare a spreadsheet that includes the analysis and reporting requirements listed in the tasks below:
Tab 1:
Title page with activity number and title, authors, and date completed
Tab 2:
Delay analysis for range of maximum green times
Tab 3:
Prepare a brief report that summarizes your conclusions, your recommended maximum green
times, and the data that support your conclusions and recommendations. Include a plot of
delay vs cycle length for the results that you generated.
Consider this question: How do you set the timing parameters to balance the risks of early termination
of green and inefficiently long green time? Consider the following criteria that could be used to
produce efficient phase operations:
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The phase is not extended inefficiently for a very short queue
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The phase extends long enough to clear the standing queue
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The phase doesn’t extend beyond the time that it takes for the queue to clear
In addition to these three criteria, the following criteria could also be considered to achieve intersection
operational efficiency:
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The major street green time should be extended to serve vehicles arriving after the queue clears
without causing excessive delay to the minor street traffic
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The maximum green time should be increased in case of phase failure when a phase consistently
terminates by maxing out
Your objective in this activity is to determine the maximum green times such that the phases generally
gap out (and not max out) balanced by making sure the cycle times are not excessive and long delay
times are produced.
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Setting the Maximum Green Timing Parameter for All
Approaches of an Intersection