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Timing Design: Theory and Concepts  Green Split Calculations
Once you have the total cycle length, you can determine the
length of time that is available for green signal indications by
subtracting the intergreen periods from the total cycle
length. But, the result is useless unless you know how to
allocate it to all of the phases of the cycle.   As explained in
the module about critical movement analysis, the critical
movements or lanes are used to distribute the available green
time among all of the phases. The flow ratio for a movement or
lane is the actual (design) flow rate, for that entity, divided
by the saturation flow rate. The critical flow ratio, which is
the one that is important for this calculation, is the flow
ratio for the critical movement or lane.   Green time is
allocated using a ratio equation. Each phase is given a portion
of the available green time that is consistent with the ratio of
its critical flow ratio to the sum of all t